Our Multi-Agent Architecture for Smarter Advertising | Spotify Engineering

The post argues that fragmented advertising workflows, not backend infrastructure, are the core problem. Although buying channels share services and data, their planning and optimization logic is repeatedly reimplemented across channels and surfaces, causing drift and technical debt. The proposed solution is a shared agentic decision layer that interprets advertiser goals, orchestrates existing Ads APIs, and applies consistent reasoning across products.

Fragmented Workflows Across a Shared Backend

• Direct, Self-Serve, and Programmatic buying use largely consolidated infrastructure but retain different workflows and decision logic.
• Spotify Ads Manager, Salesforce, Slack, and internal tools contain overlapping automation.
• Budget allocation, inventory selection, reach, efficiency, and STR decisions are repeatedly implemented in different places.
• Incremental workflow changes therefore create duplicated maintenance work and inconsistent behavior.

Why Conventional Workflow Services Fall Short

• Hard-coded state machines and REST services are poorly suited to combinatorial planning tasks.
• Campaign planning depends on:
  • User and advertiser characteristics
  • Available inventory and audiences
  • Business priorities
  • Forecasts, performance, and optimization goals
• A workflow optimized for one channel or “happy path” will not adapt well as requirements change.
• Improvements to decision logic must be replicated across every product surface, increasing the risk of divergence.

The Missing Intent Layer

• Existing systems can perform individual actions such as creating line items, running forecasts, and retrieving insights.
• They do not consistently translate high-level objectives into:
  • A sequence of tool calls
  • Explicit tradeoffs
  • Validation and safety checks
• An objective such as maximizing reach in Brazil while protecting video inventory and meeting STR requires coordinated reasoning across multiple capabilities.

A Modular Agentic Architecture

• Campaign planning and management are modeled as cooperating specialized agents.
• Agents use shared signals, including:
  • Inventory
  • Audiences
  • STR
  • Quality and risk
  • Historical performance
• They jointly optimize advertiser goals and Spotify’s business constraints.
• Existing Ads services become tools that agents orchestrate, rather than capabilities being rebuilt in each workflow.
• A long-running orchestration layer delegates tasks while agents share context and evaluation logic.
• The same decision engine can support every buying channel and surface.

Engineering Implications

• APIs need to be designed as agent tools, rather than only as CRUD interfaces.
• Testing must include behavioral evaluation in addition to unit and integration tests.
• Observability should explain what an agent decided and why, not merely track latency and errors.
• Safety requires guardrails for semi-autonomous decisions, beyond ordinary input validation.
• The approach avoids both duplicated deterministic workflows and a brittle, centralized rules engine for probabilistic, ML-heavy advertising logic.

The overall recommendation is to centralize campaign decision-making in a reusable agentic platform while keeping existing services as specialized tools. This should reduce duplicated workflow logic, make improvements consistent across products, and allow advertising workflows to evolve without repeatedly rebuilding them.