4. Implementation and Integration (26%)
Domain 2 is where architectural knowledge meets engineering reality. The exam doesn't ask whether you can describe an agent — it asks whether you can read a multi-constraint scenario (low latency, high security, enterprise integration requirements) and identify the correct combination of agent services (Strands Agents, Amazon Bedrock AgentCore), Step Functions, API Gateway, and CI/CD tooling. Every section here is scenario-dense.
Three patterns dominate Domain 2: agentic architectures (when and how agents work, their failure modes, and the new MCP standard), enterprise integration (how GenAI components plug into existing AWS infrastructure), and FM API patterns (streaming, resilience, and intelligent routing at production scale). Weakness in any of the three will cost you multiple exam questions.
⚠️ Common Misconception: A managed agent service (the Amazon Bedrock AgentCore managed harness for new builds, or Bedrock Agents Classic for existing customers) and custom Step Functions + Lambda agent implementations are equivalent choices with different complexity levels. They are not — a managed agent service provides a managed reasoning loop, memory, and tool orchestration that takes weeks to replicate with Step Functions. The trade-off is control vs. speed-to-production, and the exam tests whether you recognize when each is appropriate.