LINE/Generative AI

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Unifying Analysis Through the Power of Analytics Agents: Work Innovation and Role Transformation in the Generative AI Era at a Professional Organization

PJ One Piece is LY Corporation’s initiative to connect business questions, data analysis, insight generation, and next-action planning through generative AI. Its analysis agent reduced typical turnaround times from about two weeks to roughly 10 minutes, enabling hundreds of analyses each month and adoption by more than half of an early-adopter business unit. The project treats AI not as a chat interface, but as an analysis platform that connects data, knowledge, people, and organizational processes. ## Three Disconnects Behind the Project - **Business and data:** Even with a data warehouse and BI tools, business users still needed to understand SQL, tables, column definitions, KPI rules, and result interpretation. - **Within the analysis process:** Task definition, analysis design, execution, review, and action planning were often handled by different people or tools, causing context loss, rework, delays, and inconsistent quality. - **Across domains:** Useful analysis patterns and domain knowledge remained isolated because services used different KPIs, table structures, business assumptions, and review criteria. ## The Analysis Agent as a Connector - Users ask questions in natural language without needing to know SQL or database structures. - The agent: - Clarifies the business objective and missing assumptions. - Finds relevant data and creates an analysis plan. - Executes queries and specialized analyses. - Interprets results and produces visualizations or reports. - Suggests further analysis and possible next actions. - The platform consists of: - A user-facing application. - An LLM-based agent for reasoning and tool use. - Tools for SQL, Python, document search, and visualization. - A knowledge base containing domain information, skills, and table metadata. - Logging, feedback, monitoring, and evaluation systems. - Domain knowledge is added through a plugin-like structure, while logs and feedback continuously improve the system. ## Turning Business Questions into Analysis Requirements - Natural-language questions often leave important assumptions unspecified, such as: - Target population or campaign definition. - Analysis period and comparison group. - KPI definitions. - Aggregation level. - Exclusion conditions. - Rather than requiring users to write detailed prompts, the agent uses domain knowledge to determine what can be inferred and asks only about unresolved points. - Knowledge bases document service context, KPI definitions, aggregation cautions, policy information, and review requirements. - Table metadata explains available tables, columns, appropriate use cases, samples, partition requirements, and usage restrictions. ## Reaching Data Safely and Reliably - Table metadata is revealed progressively: - The agent first narrows down relevant tables. - It then retrieves detailed definitions and usage rules only for those tables. - Analysis-oriented wide tables or logical views combine transaction data with commonly needed attributes, reducing complicated joins and SQL-generation errors. - SQL is checked before and after execution to enforce: - `SELECT`-only access. - Approved tables and usage rules. - Required partition conditions. - Restrictions on sensitive or personal data. - Result-size limits. - These guardrails allow the agent to perform analysis flexibly without exposing data or infrastructure to unnecessary risks. ## Preserving Context Across the Analysis Process - PJ One Piece uses a supervisor-style multi-agent architecture. - A main agent maintains: - The user’s request and business objective. - The current analysis plan. - Findings and constraints discovered so far. - Remaining questions and decision points. - Specialized sub-agents handle tasks such as statistical testing, time-series analysis, clustering, and independent review. - This separates complex or specialized work from the main context while preserving overall continuity. - Progress updates expose discoveries, design decisions, data limitations, and constraints so users can adjust direction during longer analyses. ## Building Reusable Organizational Capability - Logs record agent actions, assumption checks, analysis designs, generated SQL, errors, and outputs. - User and analyst feedback helps identify whether improvements are needed in prompts, tools, data, or reusable skills. - Repeated workflows are formalized as skills, including: - General-purpose methods such as time-series and clustering analysis. - Domain-specific workflows such as monthly reporting or policy monitoring. - Skills document required assumptions, comparison axes, cautions, and interpretation methods. - Over time, isolated domain knowledge becomes reusable organizational analysis capability. ## Business Impact - In early deployment, the platform expanded data use beyond data scientists to product owners and frontline employees. - More than half of the participating business unit’s members use it. - Analysis turnaround fell from an average of approximately two weeks to about 10 minutes. - The platform now supports hundreds of analyses per month and serves as a daily starting point for business questions. PJ One Piece’s main recommendation is to design AI analysis as an end-to-end operating platform—not merely an automated SQL or chatbot tool. Combining structured domain knowledge, safe data access, contextual multi-agent workflows, reusable skills, and continuous evaluation can make analysis faster while steadily improving its quality and organizational reach.

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ODW #8: A Hands-On Internal Workshop on Accelerating Incident Response and FAQ Generation with Slack MCP

LY Corporation’s Orchestration Development Workshop demonstrated how Slack MCP can turn scattered Slack conversations into structured operational knowledge. Using AI, employees can summarize incidents, generate reports, create FAQs, and publish results to Confluence with minimal setup. The workshop’s central conclusion was that hands-on practice, reusable skills, and human review are essential for turning new AI capabilities into practical workplace tools. ## The Information and Adoption Challenge - Slack contains valuable real-time information from incident response, customer inquiries, and project discussions. - Much of this information remains unstructured because employees lack time to document it. - Documentation quality varies by author, causing useful knowledge to become difficult to find. - Although Slack MCP became available internally in March 2026, adoption barriers remained: - Limited time to explore new tools - Concerns about complex configuration - Slow internal distribution of technical knowledge ## Introducing Slack MCP Through Hands-On Practice - Slack MCP is an internally developed MCP server connected to company authentication. - Employees can access internal Slack data without issuing personal tokens or configuring OAuth. - The workshop began with a simple exercise: - Launch a coding tool such as Claude Code - Ask the AI to post “Hello” in a designated Slack channel - Confirm that the message was actually posted - This immediate success helped participants understand MCP’s practical capabilities. ## Combining Slack MCP with Other MCP Servers Slack MCP supports several core operations: - Reading messages and threads - Posting messages and performing actions - Looking up channels and members - Searching Slack content Combined with other MCP servers, it can support broader workflows: - Slack plus Confluence MCP: Generate and publish project reports or FAQs - Slack plus Jira MCP: Create work tickets from discussions - Slack conversations can be transformed into structured documents rather than remaining isolated in chat history. ## Automatically Creating FAQs from Slack Inquiries The first major exercise converted repeated support discussions into reusable knowledge. - Slack inquiry threads were collected and converted into FAQ-formatted Markdown. - Existing Confluence content was checked to identify duplicates. - New FAQs were published as child pages under an existing Confluence knowledge base. - The output was formatted as a table containing: - Symptoms - Causes - Solutions The workflow was packaged into reusable skills such as: - `slack-to-faq`: Searches recent inquiry threads and generates new FAQ files - `faq-to-confluence`: Converts and publishes the FAQs to Confluence This demonstrated how MCP can automate the entire path from conversation search to knowledge-base publication. ## Supporting Incident Response The second exercise focused on reducing the time needed to understand and document incidents. ### Rapid Situation Summaries Participants could ask the AI to summarize an outage in natural language. MCP searched relevant Slack threads and organized the information into: - Current resolution status - Customer impact - Actions being taken by team members - A chronological timeline This helps managers or newly joining responders understand the situation quickly without reading every thread. ### Automated Incident Reports After resolution, the AI generated reports in a specified format, including: - Incident and detection times - Duration - Root cause - Affected users and features - Whether data was lost - Remediation steps The `slack-incident-status` and `slack-incident-report` skills separated real-time status checking from post-incident documentation. ## Practical Guidelines and Safeguards - Clean and constrain source data before processing it: - Compare results with existing Confluence FAQs - Filter messages using reactions or other markers - Limit searches to relevant channels and threads - Do not publish AI-generated documents without review. - Check for personal information and confirm that the output accurately reflects the source conversations. - Include links or references to the original Slack threads. - Specify the desired output structure, such as a three-column table for symptoms, causes, and solutions. - Convert successful prompts into reusable skills so teams can avoid rewriting complex instructions and maintain consistent output quality. ## Lessons from the Workshop - **Timing matters:** Holding the workshop soon after Slack MCP became available captured user interest and accelerated experimentation. - **Practice is more effective than explanation:** Starting with a simple Slack post and progressing to FAQs and incident reports made the benefits immediately tangible. - **Real work makes training relevant:** Inquiry handling and incident response were chosen because they are common, time-consuming tasks. - **Reusable skills improve adoption:** Prompt patterns were tested manually, refined, saved as skills, and shared with participants for continued workplace use. The recommended approach is to introduce new AI tools through timely, task-focused workshops, then refine successful workflows into shared skills. MCP can greatly reduce the effort of operational documentation, but human validation remains necessary before generated knowledge is published.

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AI Didn’t Replace QA; It Expanded It

Generative AI has not replaced QA at LINE Album; it has expanded QA’s scope and influence. The team found that QA productivity depends less on executing tests quickly than on organizing and interpreting large amounts of scattered information. By embedding AI into event-driven quality workflows, QA engineers now focus more on risk assessment, test strategy, and final decisions. ## QA as a Quality Architect - QA operates across the entire product lifecycle: planning, development, testing, release, and post-release feedback. - Its responsibilities include: - Identifying design risks during planning - Assessing the impact of code changes - Designing test strategies - Validating releases - Connecting user feedback and operational data to product improvements - QA information comes from many sources: - Planning and technical documents - Slack discussions and decisions - Jira tickets and pull requests - Automated test scripts and logs - App Store and Google Play reviews - The central challenge is therefore managing information volume and complexity, not merely increasing testing speed. ## From AI Assistant to AI-Driven Workflow - Initially, AI was used interactively to: - Summarize documents - Draft test cases - Organize bug reports - Document reproduction steps - This improved individual productivity but required QA engineers to manually collect and prepare information. - LINE Album QA instead built an automated quality platform with more than 30 workflows. - AI now reacts automatically to events such as: - Jira issue creation - Code changes and pull requests - Test execution - User feedback collection - AI gathers, analyzes, and structures quality information, while QA engineers interpret risks and make decisions. ## Scheduling and Webhook Automation ### Scheduled Analysis - Scheduled workflows periodically collect and summarize quality data. - Examples include: - Daily App Store review classification - API test result summaries sent to Slack - UI automation reports - Weekly QA activity and issue reports - QA engineers spend less time gathering data and more time evaluating risks and verifying important findings. ### Webhook-Based Analysis - Webhook workflows run immediately when quality-related events occur. - Examples include: - Summarizing the potential impact of merged code changes - Creating meeting notes when Slack discussions end - Analyzing and visualizing automated test results - This allows the team to recognize important quality signals much earlier. ## The AI-Supported QA Workday - UI tests run through MagicPod for Android and iOS, with results updated in Jira and shared in Slack. - Failed tests trigger analysis to determine whether they are flaky tests and identify possible causes. - Pytest-based API tests are similarly reported to Jira and Slack. - Daily Scrum workflows automatically provide: - Current test progress - Scrum board and issue dashboard links - Unresolved issues - Jira mentions requiring QA attention - App reviews are analyzed daily, classified as positive or negative, translated into Japanese and Korean, and summarized for the team. - During focused work periods, QA engineers use AI-generated information to plan quality activities, execute tests, monitor workflows, and summarize relevant discussions or documents. - End-of-day workflows summarize completed work and remaining issues. ## AI as a Test Design Partner - By 2026, AI generated approximately 90% of LINE Album QA’s test-case drafts. - Simple prompting produced many generic scenarios but failed to capture: - The reason a feature was introduced - Historical defect patterns - Effects on existing user flows - The team improved results by supplying broader context, including: - Specifications and development tickets - Change rationale - Previous Jira issues - Test history - Recurring bug patterns ### Multi-Agent Test Generation - An orchestrator coordinates five specialized sub-agents: - **Plan-Analyzer:** Examines requirements, feature descriptions, and images. - **Dev-Analyzer:** Adds implementation and development-ticket context. - **TestCase-Generator:** Produces normal, exceptional, boundary-value, platform-specific, and prioritized scenarios. - **TestCase-Validator:** Checks coverage, traceability, completeness, Given/When/Then structure, priorities, and platform coverage. - **Quality-Inspector:** Uses prior feedback and quality evaluations to improve future generations. - The workflow expands testing beyond stated requirements by incorporating defects that have historically occurred. - Validation feedback creates an iterative loop, making the output more executable and useful over time. AI is most valuable when it is connected to the organization’s accumulated context and quality signals—not when it is used merely as a chat-based drafting tool. The recommended approach is to automate information collection and analysis while keeping QA responsible for interpretation, prioritization, and final quality decisions.

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Journey Toward Perfect AI Guardrails

NeurIPS 2025 research shows that AI safety is moving beyond simple post-training alignment and output filtering toward system-level, modular defenses. New approaches intervene in reasoning, multimodal interpretation, policy enforcement, and continuous evaluation to balance safety with latency and usefulness. The central conclusion is that deployable AI requires adaptable guardrails designed for real-world systems, not isolated attack benchmarks. ## The Shift Toward Practical AI Safety - Guardrails protect AI services from harmful instructions, privacy leaks, confidential-data exposure, bias, prompt injection, and other failures. - NeurIPS 2025 reflects a broader shift: - From post-training safety tuning to intervention in reasoning mechanisms. - From text-only LLMs to VLMs, RAG systems, and reasoning models. - From laboratory attack scenarios to the practical balance between utility and safety. - The article focuses on guardrail frameworks, multimodal moderation, prompt injection and jailbreaks, hallucinations, and over-refusal. ## Modular Guardrail Frameworks **PRIME Guardrails: A General, Low-Latency Safety Framework for Generative AI** addresses the trade-off between rigorous safety checks and response latency through a modular architecture: - **Policy specification:** Declarative, human-readable rules separate policies from model parameters, allowing legal or policy teams to control behavior. - **Risk sensing and scoring:** Asynchronous detectors combine lexical rules, semantic similarity, and lightweight classifiers. Early exit blocks obvious attacks quickly while allowing domain-specific calibration. - **Intervention router:** A deterministic controller chooses whether to allow, rewrite, or reject an interaction based on policies and risk scores. - **Monitoring and memory:** Lightweight records preserve decisions and rejection reasons for predictability and auditing. - **Evaluation and evolution:** Red-team recipes and automated vulnerability testing help the system adapt to new attack methods. The framework supports defense in depth without running every expensive safety mechanism sequentially. Its modularity, auditing capabilities, and continuous-evaluation loop make it suitable for production environments. ## Turning Governance Policies into Code **Policy-as-Prompt: Turning AI Governance Rules into Guardrails for AI Agents** converts informal organizational materials into runtime-enforceable controls. - The framework analyzes sources such as PRDs, technical design documents, regulations, and source code. - It builds a **source-linked policy tree** connecting individual rules to their original documents. - The policies are compiled into lightweight prompt-based classifiers. - When an agent rejects a request, the system can trace the decision back to its legal or organizational basis. - The approach helps enforce: - Least-privilege access. - Data minimization. - Restrictions on out-of-scope tasks. - Protection against prompt injection. - It may be especially valuable in regulated industries such as finance and healthcare, where frequently changing policies create substantial technical debt. ## Multimodal Safety and VLM Reasoning Vision-language models create new safety challenges because harmful meaning can emerge from interactions between images and text. **GuardReasoner-VL: Safeguarding VLMs via Reinforced Reasoning** trains models to reason about combined modalities rather than classifying each input independently. - It addresses cases where harmless text obscures harmful visual content, such as an image of a bloodied knife paired with “cooking.” - Its GRPO-based training process includes: - **Safety-aware data concatenation** to create difficult examples containing hidden or mixed harmful content. - **Dynamic clipping** that encourages exploration early in training and tighter refinement later. - **Length-aware safety rewards** that reward concise conclusions supported by reasoning. - The method aims to detect subtle harms such as hate speech hidden in memes and visual metaphors. ## Hidden Vulnerabilities in Multimodal Training Data **VLMs can Aggregate Scattered Training Patches** demonstrates that filtering training images may not be sufficient. - A harmful image can be divided into individually innocuous patches and included in training. - A VLM may reconstruct the harmful concept by associating patches that share the same text label. - The paper calls this behavior **visual stitching**, related to cross-sample reasoning and inductive out-of-context reasoning. - Text labels such as “safe” or “unsafe” can help the model connect fragmented visual information and infer the original image-level meaning. - This suggests that safety evaluations must inspect not only final outputs but also: - Input-processing pipelines. - Cross-sample interactions. - Internal or latent representations. The available article ends while introducing research on distorted safety perception, so that section cannot be summarized further from the provided text. In practice, organizations should combine modular, low-latency enforcement with traceable policy management and multimodal evaluations that test hidden interactions—not just obvious harmful prompts or images.

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A Business Trip to Japan After Only One (opens in new tab)

Joining the Developer Relations (DevRel) team at LINE Plus, a new employee was immediately thrust into a high-stakes business trip to Japan just one week after onboarding to support major global tech events. This immersive experience allowed the recruit to rapidly grasp the company’s engineering culture by facilitating cross-border collaboration and managing large-scale technical conferences. Ultimately, the journey highlights how a proactive onboarding strategy and a culture of creative freedom enable DevRel professionals to bridge the gap between complex engineering feats and community engagement. ### Global Collaboration at Tech Week * The trip centered on participating in **Tech-Verse**, a global conference featuring simultaneous interpretation in Korean, English, and Japanese, where the focus was on maintaining operational detail across diverse technical sessions. * Operational support was provided for **Hack Day**, an in-house hackathon that brought together engineers from various countries to collaborate on rapid prototyping and technical problem-solving. * The experience facilitated direct coordination with DevRel teams from Japan, Thailand, Taiwan, and Vietnam, establishing a unified approach to technical branding and regional community support. * Post-event responsibilities included translating live experiences into digital assets, such as "Shorts" video content and technical blog recaps, to maintain engagement after the physical event concluded. ### Modernizing Internal Technical Sharing * The **Tech Talk** series, a long-standing tradition with over 78 sessions, was used as a platform to experiment with "B-grade" humorous marketing—including quirky posters and cup holders—to drive offline participation in a remote-friendly work environment. * To address engineer feedback, the format shifted from passive lectures to **hands-on practical sessions** focusing on AI implementation. * Specific technical workshops demonstrated how to use tools like **Claude Code** and **ChatGPT** to automate workflows, such as generating weekly reports by integrating **Jira tickets with internal Wikis**. * Preparation for these sessions involved creating detailed environment setup guides and troubleshooting protocols to ensure a seamless experience for participating developers. ### Scaling AI Literacy via AI Campus Day * The **AI Campus Day** was a large-scale event designed for over 3,000 participants, aimed at lowering the barrier to entry for AI adoption across all departments. * The "Event & Operation" role involved creating interactive AI photo zones using **Gemini** to familiarize employees with new internal AI tools in a low-pressure setting. * Event production utilized AI-driven assets, including AI-generated voices and icons, to demonstrate the practical utility of these tools within standard business communication and video guides. * The success of the event relied on "participation design," ensuring that even non-technical staff could engage with AI concepts through hands-on play and peer mentoring. For organizations looking to strengthen their technical culture, this experience suggests that integrating new hires into high-impact global projects immediately can be a powerful onboarding tool. Providing DevRel teams the psychological safety to experiment with unconventional marketing and hands-on technical workshops is essential for maintaining developer engagement in a hybrid work era.

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We held AI Campus Day to improve (opens in new tab)

LY Corporation recently hosted "AI Campus Day," a large-scale internal event designed to bridge the gap between AI theory and practical workplace application for over 3,000 employees. By transforming their office into a learning campus, the company successfully fostered a culture of "AI Transformation" through peer-led mentorship and task-specific experimentation. The event demonstrated that internal context and hands-on participation are far more effective than traditional external lectures for driving meaningful AI literacy and productivity gains. ## Hands-on Experience and Technical Support * The curriculum featured 10 specialized sessions across three tracks—Common, Creative, and Engineering—to ensure relevance for every job function. * Sessions ranged from foundational prompt engineering for non-developers to advanced technical topics like building Model Context Protocol (MCP) servers for engineers. * To ensure smooth execution, the organizers provided comprehensive "Session Guides" containing pre-configured account settings and specific prompt templates. * The event utilized a high support ratio, with 26 teaching assistants (TAs) available to troubleshoot technical hurdles in real-time and dedicated Slack channels for sharing live AI outputs. ## Peer-Led Mentorship and Internal Context * Instead of hiring external consultants, the program featured 10 internal "AI Mentors" who shared how they integrated AI into their actual daily workflows at LY Corporation. * Training focused exclusively on company-approved tools, including ChatGPT Enterprise, Gemini, and Claude Code, ensuring all demonstrations complied with internal security protocols. * Internal mentors were able to provide specific "company context" that external lecturers lack, such as integrating AI with existing proprietary systems and data. * A rigorous three-stage quality control process—initial flow review, final end-to-end dry run, and technical rehearsal—was implemented to ensure the educational quality of mentor-led sessions. ## Gamification and Cultural Engagement * The event was framed as a "festival" rather than a mandatory training, using campus-themed motifs like "enrollment" and "school attendance" to reduce psychological barriers. * A "Stamp Rally" system encouraged participation by offering tiered rewards, including welcome kits, refreshments, and subscriptions to premium AI tools. * Interactive exhibition booths allowed employees to experience AI utility firsthand, such as an AI photo zone using Gemini to generate "campus-style" portraits and an AI Agent Contest booth. * Strong executive support played a crucial role, with leadership encouraging staff to pause routine tasks for the day to focus entirely on AI experimentation and "playing" with new technologies. To effectively scale AI literacy within a large organization, it is recommended to move away from passive, one-size-fits-all lectures. Success lies in leveraging internal experts who understand the specific security and operational constraints of the business, and creating a low-pressure environment where employees can experiment with hands-on tasks relevant to their specific roles.

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A month-long project in (opens in new tab)

This blog post explores how LY Corporation reduced a month-long development task to just five days by leveraging "vibe coding" with Generative AI tools like ChatGPT and Cursor. By shifting from traditional, rigid documentation to an iterative, demo-first approach, developers can rapidly validate multiple UI/UX solutions for complex problems like restaurant menu registration. The author concludes that AI's ability to handle frequent re-work makes it more efficient to "build fast and iterate" than to aim for perfection through long-form specifications. ### Strategic Shift to Rapid Prototyping * Traditional development cycles (spec → design → dev → fix) are often too slow to keep up with market trends due to heavy documentation and impact analysis. * The "vibe coding" approach prioritizes creating "working demos" over perfect specifications to find "good enough" answers through rapid feedback loops. * AI reduces the psychological and logistical burden of "starting over," allowing developers to refine the context and quality of outputs through repeated interaction without the friction of manual re-documentation. ### Defining Requirements and Solution Ideation * Initial requirements are kept minimal, focusing only on the core mission, top priorities, and essential data structures (e.g., product name, image, description) to avoid limiting AI creativity. * ChatGPT is used to generate a wide range of solution candidates, which are then filtered into five distinct approaches: Stepper Wizards, Live Previews with Quick Add, Template/Cloning, Chat Input, and OCR-based photo scanning. * This stage emphasizes volume and variety, using AI-generated pros and cons to establish selection criteria and identify potential UX bottlenecks early in the process. ### Detailed Design and Multi-Solution Wireframing * Each of the five chosen solutions is expanded into detailed screen flows and UI elements, such as progress bars, bottom sheets, and validation logic. * Prompt engineering is used iteratively; if an AI-generated result lacks a specific feature like "temporary storage" or "mandatory field validation," the prompt is adjusted to regenerate the design instantly. * The focus remains on defining the "what" (UI elements) and "how" (user flow) through textual descriptions before moving to actual coding. ### Implementation with Cursor and Flutter * Cursor is utilized to generate functional code based on the refined wireframes, using Flutter as the framework to ensure rapid cross-platform development for both iOS and Android. * The development follows a "skeleton-first" approach: first creating a main navigation hub with five entry points, then populating each individual solution module one by one. * Technical architecture decisions, such as using Riverpod for state management or SQLite for data storage, are layered onto the demo post-hoc, reversing the traditional "stack-first" development order to prioritize functional validation. ### Recommendation To maximize efficiency, developers should treat AI as a partner for high-speed iteration rather than a one-shot tool. By focusing on creating functional demos quickly and refining them through direct feedback, teams can bypass the bottlenecks of traditional software requirements and deliver user-centric products in a fraction of the time.

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PD1 AI Hackathon: Into the (opens in new tab)

The PD1 AI Hackathon 2025 served as a strategic initiative by LY Corporation to embed innovative artificial intelligence directly into the LINE messaging ecosystem. Over 60 developers collaborated during an intensive 48-hour session to transition AI from a theoretical concept into practical features for messaging, content, and internal development workflows. The event successfully produced several high-utility prototypes that demonstrate how AI can enhance user safety, creative expression, and technical productivity. ## Transforming Voice Communication through NextVoIP * The "NextVoIP" project utilized Speech-to-Text (STT) technology to convert 1:1 and group call audio into real-time data for AI analysis. * The system was designed to provide life security features by detecting potential emergency situations or accidents through conversation monitoring. * AI acted as a communication assistant by suggesting relevant content and conversation topics to help maintain a seamless flow during calls. * Features were implemented to allow callers to enjoy shared digital content together, enriched by AI-driven recommendations. ## Creative Expression with MELODY LINE * This project focused on the intersection of technology and art by converting chat conversations into unique musical compositions. * The system analyzed the context and emotional sentiment of messages to automatically generate melodies that matched the atmosphere of the chat. * The implementation showcased the potential for generative AI to provide a multi-sensory experience within a standard messaging interface. ## AI-Driven QA and Test Automation * The grand prize-winning project, "IPD," addressed the bottleneck of repetitive manual testing by automating the entire Quality Assurance lifecycle. * AI was utilized to automatically generate and manage complex test cases, significantly reducing the manual effort required for mobile app validation. * The system included automated test execution and a diagnostic feature that identifies the root cause of failures when a test results in an error. * The project was specifically lauded for its immediate "production-ready" status, offering a direct path to improving development speed and software reliability. The results of this hackathon suggest that the most immediate value for AI in large-scale messaging platforms lies in two areas: enhancing user experience through contextual awareness and streamlining internal engineering via automated QA. Organizations should look toward integrating AI-driven testing tools to reduce technical debt while exploring real-time audio and text analysis to provide proactive security and engagement features for users.

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Hey, won't you become a (opens in new tab)

Hack Day 2025 serves as a cornerstone of LY Corporation’s engineering culture, bringing together diverse global teams to innovate beyond their daily operational scopes. By fostering a high-intensity environment focused on creative freedom, the event facilitates technical growth and strengthens interpersonal bonds across international branches. This 19th edition demonstrated how rapid prototyping and cross-functional collaboration can transform abstract ideas into functional AI-driven prototypes within a strict 24-hour window. ### Structure and Participation Dynamics * The hackathon follows a "9 to 9" format, providing exactly 24 hours of development time followed by a day for presentations and awards. * Participation is inclusive of all roles, including developers, designers, planners, and HR staff, allowing for holistic product development. * Teams can be "General Teams" from the same legal entity or "Global Mixed Teams" comprising members from different regions like Korea, Japan, Taiwan, and Vietnam. * The Developer Relations (DevRel) team facilitates team building for remote employees using digital collaboration tools like Zoom and Miro. ### AI-Powered Personality Analysis Project * The author's team developed a "Scouter" program inspired by Dragon Ball, designed to measure professional "combat power" based on communication history. * The system utilizes Slack bots and AI models to analyze message logs and map them to the Big 5 Personality traits (Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism). * Professional metrics are visualized as game-like character statistics to make personality insights engaging and less intimidating. * While the original plan involved using AI to generate and print physical character cards, hardware failures with photo printers forced a technical pivot to digital file downloads. ### High-Pressure Presentation and Networking * Every team is allotted a strict 90-second window to pitch their product and demonstrate a live demo. * The "90-second rule" includes a mandatory microphone cutoff to maintain momentum and keep the large-scale event engaging for all attendees. * Dedicated booth sessions follow the presentations, allowing participants to provide hands-on experiences to colleagues and judges. * The event emphasizes "Perfect the Details," a core company value, by encouraging teams to utilize all available resources—from whiteboards to AI image generators—within the time limit. ### Environmental Support and Culture * The event occupies an entire office floor, providing a high-density yet comfortable environment designed to minimize distractions during the "Hack Time." * Cultural exchange is encouraged through "humanity snacks," where participants from different global offices share local treats in dedicated rest areas. * Strategic scheduling, such as "Travel Days" for international participants, ensures that teams can focus entirely on technical execution once the event begins. Participating in internal hackathons provides a vital platform for testing new technologies—like LLMs and personality modeling—that may not fit into immediate product roadmaps. For organizations with hybrid work models, these intensive in-person events are highly recommended to bridge the communication gap and build lasting trust between global teammates.

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LY's Tech Conference, ' (opens in new tab)

LY Corporation’s Tech-Verse 2025 conference highlighted the company's strategic pivot toward becoming an AI-centric organization through the "Catalyst One Platform" initiative. By integrating the disparate infrastructures of LINE and Yahoo! JAPAN into a unified private cloud, the company aims to achieve massive cost efficiencies while accelerating the deployment of AI agents across its entire service ecosystem. This transformation focuses on empowering engineers with AI-driven development tools to foster rapid innovation and deliver a seamless, "WOW" experience for global users. ### Infrastructure Integration and the Catalyst One Platform To address the redundancies following the merger of LINE and Yahoo! JAPAN, LY Corporation is consolidating its technical foundations into a single internal ecosystem known as the Catalyst One Platform. * **Private Cloud Advantage:** The company maintains its own private cloud to achieve a four-fold cost reduction compared to public cloud alternatives, managed by a lean team of 700 people supporting 500,000 servers. * **Unified Architecture:** The integration spans several layers, including Infrastructure (Project "DC-Hub"), Cloud (Project "Flava"), and specialized Data and AI platforms. * **Next-Generation Cloud "Flava":** This platform integrates existing services to enhance VM specifications, VPC networking, and high-performance object storage (Ceph and Dragon). * **Information Security:** A dedicated "SafeOps" framework is being implemented to provide governance and security across all integrated services, ensuring a safer environment for user data. ### AI Strategy and Service Agentization A core pillar of LY’s strategy is the "AI Agentization" of all its services, moving beyond simple features to proactive, personalized assistance. * **Scaling GenAI:** Generative AI has already been integrated into 44 different services within the group. * **Personalized Agents:** The company is developing the capacity to generate millions of specialized agents that can be linked together to support the unique needs of individual users. * **Agent Ecosystem:** The goal is to move from a standard platform model to one where every user interaction is mediated by an intelligent agent. ### AI-Driven Development Transformation Beyond user-facing services, LY is fundamentally changing how its engineers work by deploying internal AI development solutions to all staff starting in July. * **Code and Test Automation:** Proof of Concept (PoC) results showed a 96% accuracy rate for "Code Assist" and a 97% reduction in time for "Auto Test" procedures. * **RAG Integration:** The system utilizes Retrieval-Augmented Generation (RAG) to leverage internal company knowledge and guidelines, ensuring high-quality, context-aware development support. * **Efficiency Gains:** By automating repetitive tasks, the company intends for engineers to shift their focus from maintenance to creative service improvement and innovation. The successful integration of these platforms and the aggressive adoption of AI-driven development tools suggest that LY Corporation is positioning itself to be a leader in the "AI-agent" era. For technical organizations, LY's model serves as a case study in how large-scale mergers can leverage private cloud infrastructure to fund and accelerate a company-wide AI transition.

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Hosting the Tech Conference Tech- (opens in new tab)

LY Corporation is hosting its global technology conference, Tech-Verse 2025, on June 30 and July 1 to showcase the engineering expertise of its international teams. The event features 127 sessions centered on core themes of AI and security, offering a deep dive into how the group's developers, designers, and product managers solve large-scale technical challenges. Interested participants can register for free on the official website to access the online live-streamed sessions, which include real-time interpretation in English, Korean, and Japanese. ### Conference Overview and Access * The event runs for two days, from 10:00 AM to 6:00 PM (KST), and is primarily delivered via online streaming. * Registration is open to the public at no cost through the Tech-Verse 2025 official website. * The conference brings together technical talent from across the LY Corporation Group, including LINE Plus, LINE Taiwan, and LINE Vietnam. ### Multi-Disciplinary Technical Tracks * The agenda is divided into 12 distinct categories to cover the full spectrum of software development and product lifecycle. * Day 1 focuses on foundational technologies: AI, Security, Server-side development, Private Cloud, Infrastructure, and Data Platforms. * Day 2 explores application and management layers: AI Use Cases, Frontend, Mobile Applications, Design, Product Management, and Engineering Management. ### Key Engineering Case Studies and Sessions * **AI and Data Automation:** Sessions explore the evolution of development processes using AI, the shift from "Vibe Coding" to professional AI-assisted engineering, and the use of Generative AI to automate data pipelines. * **Infrastructure and Scaling:** Presentations include how the "Central Dogma Control Plane" connects thousands of services within LY Corporation and methods for improving video playback quality for LINE Call. * **Framework Migration:** A featured case study details the strategic transition of the "Demae-can" service from React Native to Flutter. * **Product Insights:** Deep dives into user experience design and data-driven insights gathered from LINE Talk's global user base. Tech-Verse 2025 provides a valuable opportunity for developers to learn from real-world deployments of AI and large-scale infrastructure. Given the breadth of the 127 sessions and the availability of real-time translation, tech professionals should review the timetable in advance to prioritize tracks relevant to their specific engineering interests.

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AI and Writer's Partnership (opens in new tab)

LY Corporation is addressing the chronic shortage of high-quality technical documentation by treating the problem as an engineering challenge rather than a training issue. By utilizing Generative AI to automate the creation of API references, the Document Engineering team has transitioned from a "manual craftsmanship" approach to an "industrialized production" model. While the system significantly improves efficiency and maintains internal context better than generic tools, the team concludes that human verification remains essential due to the high stakes of API accuracy. ### Contextual Challenges with Generic AI Standard coding assistants like GitHub Copilot often fail to meet the specific documentation needs of a large organization. * Generic tools do not adhere to internal company style guides or maintain consistent terminology across projects. * Standard AI lacks awareness of internal technical contexts; for example, generic AI might mistake a company-specific identifier like "MID" for "Member ID," whereas the internal tool understands its specific function within the LY ecosystem. * Fragmented deployment processes across different teams make it difficult for developers to find a single source of truth for API documentation. ### Multi-Stage Prompt Engineering To ensure high-quality output without overwhelming the LLM's "memory," the team refined a complex set of instructions into a streamlined three-stage workflow. * **Language Recognition:** The system first identifies the programming language and specific framework being used. * **Contextual Analysis:** It analyzes the API's logic to generate relevant usage examples and supplemental technical information. * **Detail Generation:** Finally, it writes the core API descriptions, parameter definitions, and response value explanations based on the internal style guide. ### Transitioning to Model Context Protocol (MCP) While the prototype began as a VS Code extension, the team shifted to using the Model Context Protocol (MCP) to ensure the tool was accessible across various development environments. * Moving to MCP allows the tool to support multiple IDEs, including IntelliJ, which was a high-priority request from the developer community. * The MCP architecture decouples the user interface from the core logic, allowing the "host" (like the IDE) to handle UI interactions and parameter inputs. * This transition reduced the maintenance burden on the Document Engineering team by removing the need to build and update custom UI components for every IDE. ### Performance and the Accuracy Gap Evaluation of the AI-generated documentation showed strong results, though it highlighted the unique risks of documenting APIs compared to other forms of writing. * Approximately 88% of the AI-generated comments met the team's internal evaluation criteria. * The specialized generator outperformed GitHub Copilot in 78% of cases regarding style and contextual relevance. * The team noted that while a 99% accuracy rate is excellent for a blog post, a single error in a short API reference can render the entire document useless for a developer. To successfully implement AI-driven documentation, organizations should focus on building tools that understand internal business logic while maintaining a strict "human-in-the-loop" workflow. Developers should use these tools to generate the bulk of the content but must perform a final technical audit to ensure the precision that only a human author can currently guarantee.

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How to evaluate AI-generated images? (opens in new tab)

To optimize the Background Person Removal (BPR) feature in image editing services, the LY Corporation AMD team evaluated various generative AI inpainting models to determine which automated metrics best align with human judgment. While traditional research benchmarks often fail to reflect performance in high-resolution, real-world scenarios, this study identifies a framework for selecting models that produce the most natural results. The research highlights that as the complexity and size of the masked area increase, the gap between model performance becomes more pronounced, requiring more sophisticated evaluation strategies. ### Background Person Removal Workflow * **Instance Segmentation:** The process begins by identifying individual pixels to classify objects such as people, buildings, or trees within the input image. * **Salient Object Detection:** This step distinguishes the main subjects of the photo from background elements to ensure only unwanted figures are targeted for removal. * **Inpainting Execution:** Once the background figures are removed, inpainting technology is used to reconstruct the empty space so it blends seamlessly with the surrounding environment. ### Comparison of Inpainting Technologies * **Diffusion-based Models:** These models, such as FLUX.1-Fill-dev, restore damaged areas by gradually removing noise. While they excel at restoring complex details, they are generally slower than GANs and can occasionally generate artifacts. * **GAN-based Models:** Using a generator-discriminator architecture, models like LaMa and HINT offer faster generation speeds and competitive performance for lower-resolution or smaller inpainting tasks. * **Performance Discrepancy:** Experiments showed that while most models perform well on small areas, high-resolution images with large missing sections reveal significant quality differences that are not always captured in standard academic benchmarks. ### Evaluation Methodology and Metrics * **BPR Evaluation Dataset:** The team curated a specific dataset of 10 images with high quality-variance to test 11 different inpainting models released between 2022 and 2024. * **Single Image Quality Metrics:** Evaluated models using LAION Aesthetics score-v2, CLIP-IQA, and Q-Align to measure the aesthetic quality of individual generated frames. * **Preference and Reward Models:** Utilized PickScore, ImageReward, and HPS v2 to determine which generated images would be most preferred by human users. * **Objective:** The goal of these tests was to find an automated evaluation method that minimizes the need for expensive and time-consuming human reviews while maintaining high reliability. Selecting an inpainting model based solely on paper-presented metrics is insufficient for production-level services. For features like BPR, it is critical to implement an evaluation pipeline that combines both aesthetic scoring and human preference models to ensure consistent quality across diverse, high-resolution user photos.

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How to evaluate AI-generated images? (opens in new tab)

LY Corporation is developing a text-to-image pipeline to automate the creation of branded character illustrations, aiming to reduce the manual workload for designers. The project focuses on utilizing Stable Diffusion and Flow Matching models to generate high-quality images that strictly adhere to specific corporate style guidelines. By systematically evaluating model architectures and hyperparameters, the team seeks to transform subjective image quality into a quantifiable and reproducible technical process. ### Evolution of Image Generation Models * **Diffusion Models:** These models generate images through a gradual denoising process. They use a forward process to add Gaussian noise via a Markov chain and a reverse process to restore the original image based on learned probability distributions. * **Stable Diffusion (SD):** Unlike standard diffusion that operates in pixel space, SD works within a "latent space" using a Variational Autoencoder (VAE). This significantly reduces computational load by denoising latent vectors rather than raw pixels. * **SDXL and SD3.5:** SDXL improves prompt comprehension by adding a second text encoder (CLIP-G/14). SD3.5 introduces a major architectural shift by moving from diffusion to "Flow Matching," utilizing a Multimodal Diffusion Transformer (MMDiT) that handles text and image modalities in a single block for better parameter efficiency. * **Flow Matching:** This approach treats image generation as a deterministic movement through a vector field. Instead of removing stochastic noise, it learns the velocity required to transform a simple probability distribution into a complex data distribution. ### Core Hyperparameters for Output Control * **Seeds and Latent Vectors:** The seed is the integer value that determines the initial random noise. Since Stable Diffusion operates in latent space, this noise is essentially the starting latent vector that dictates the basic structure of the final image. * **Prompts:** Textual inputs serve as the primary guide for the denoiser. Models are trained on image-caption pairs, allowing the U-Net or Transformer blocks to align the visual output with the user’s descriptive intent. * **Classifier-Free Guidance (CFG):** This parameter adjusts the weight of the prompt's influence. It calculates the difference between noise predicted with a prompt and noise predicted without one (or with a negative prompt), allowing users to control how strictly the model follows the text instructions. ### Practical Recommendation To achieve consistent results that match a specific brand identity, it is insufficient to rely on prompts alone; developers should implement automated hyperparameter search and black-box optimization. Transitioning to Flow Matching models like SD3.5 can provide a more deterministic generation path, which is critical when attempting to scale the production of high-quality, branded assets.