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Claude Certified Architect (CCA) Prep

Prep for the Claude Certified Architect exam — the architect’s map, the core concepts, and 50 worked practice questions across all five exam domains.

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  1. 1 Claude Certified Architect (CCA) Exam Guide: All Five Domains on One Diagram The Claude Certified Architect exam mapped to one diagram — all five domains, their weights, and the five things you do to a Claude agent. Jul 24, 2026
  2. 2 MCP Explained on One Diagram: The USB-C Port for AI Tools What the Model Context Protocol actually standardizes, the client-server-tool round-trip, and when to reach for MCP vs inline functions vs RAG. Jul 24, 2026
  3. 3 RAG vs Context Engineering: Why 'RAG Is Dead' and What Replaces It RAG didn't die, it got demoted. Learn the four pillars of context engineering and why the context window is a budget, not a memory. Jul 24, 2026
  4. 4 The Agent Loop Explained: Why Ignoring Tool Results Breaks Your Agent An agent calls a tool, gets results back, then answers from memory anyway. Which part of the agent loop failed? Learn the mechanism, not just the key. Jul 24, 2026
  5. 5 How to Expose 30 Tools Across 3 Services: MCP vs Inline Tools A CCA practice question on exposing 30 tools across 3 services — why one MCP server per service beats inline function defs, with the mechanism diagram. Jul 24, 2026
  6. 6 RAG vs MCP: Which Is Which, and When to Use Each RAG retrieves knowledge, MCP exposes tools. A CCA practice question that untangles the difference with a context-budget diagram. Jul 24, 2026
  7. 7 Why Your Agent Loops Forever: Termination Conditions in the Agent Loop An agent keeps calling the same tool and never stops. This CCA practice question shows the missing exit-guard and how to fix it: max-steps plus a goal check. Jul 24, 2026
  8. 8 When Two Agents Disagree, Who Decides? The Coordinator-Subagent Pattern Two sub-agents return conflicting answers — what should the orchestrator do? The reconcile-step pattern explained, with the mechanism diagram. Jul 24, 2026
  9. 9 Your Agent Blew the Context Window: Decompose Before You Overflow A long agent run just overflowed the context window. The exam wants the first lever, not a rebuild — here's the mechanism behind the right answer. Jul 24, 2026
  10. 10 When NOT to Build an Agent Loop: Workflows vs Agents A CCA practice question on when a single-shot prompt beats an agent loop — the decision rule, the mechanism, and why the other options fail. Jul 24, 2026
  11. 11 Your Tool Said 'Ignore Your Instructions': Prompt Injection Through Tool Results A tool result contains an instruction. Learn why that's indirect prompt injection, not a hallucination, and how to draw the trust boundary. Jul 24, 2026
  12. 12 Where Does an Agent Remember Last Week? Session State vs Long-Term Memory Why an agent forgets last week's conversation by default, and the architectural fix: session state vs a persistent long-term memory store. Jul 24, 2026
  13. 13 The Cheapest Way to Cut Agent Cost: Model Routing and Cheaper Loops The cheapest lever for agent cost isn't a smaller context or fewer tools — it's routing easy steps to a cheap model and escalating only the hard ones. Jul 24, 2026
  14. 14 Why Does Claude Pick the Wrong Tool? Fixing Tool Selection Claude picks search_web instead of search_docs? Learn why tool descriptions — not schemas — drive tool selection, and how to fix it. Jul 24, 2026
  15. 15 The Model Sends 'Next Tuesday,' Not a Date: Typing Tool Parameters A tool needs a real date but the model keeps sending free text like 'next Tuesday.' The fix isn't a prompt — it's the JSON schema. Here's the mechanism. Jul 24, 2026
  16. 16 Your Tool Returns a 500 — Then What? Designing a Tool Error Contract A tool's upstream API returns HTTP 500 — should it throw, return empty, or retry? The mechanism behind structured tool error contracts. Jul 24, 2026
  17. 17 40 Tools, Wrong Picks, High Latency: Scoping Tools Per Agent An agent with 40 tools picks the wrong one and runs slow. The fix isn't more tools — it's grouping them behind namespaces or MCP servers. Jul 24, 2026
  18. 18 Same Tool, Three Agents: Inline Tool or MCP Server? A capability is reused across three agents and two teams — inline copy or one MCP server? The mechanism behind the reuse decision, explained. Jul 24, 2026
  19. 19 A Tool That Can Delete Prod: Designing Safe Destructive Tools How to expose a tool that can delete production data: least privilege plus a human-approval gate, and why the other three options fail fast. Jul 24, 2026
  20. 20 'Gets Data' Is Too Vague: How to Write Tool Descriptions That Work A CCA D2 practice question on tool descriptions: why 'gets data' breaks tool selection, and what the model actually needs to read instead. Jul 24, 2026
  21. 21 Your Tool Returns 5,000 Rows: Paginating and Shaping Tool Responses A 5,000-row tool result blows the context window. Learn why pagination, summaries, and handles beat raw dumps — and why bigger context isn't the fix. Jul 24, 2026
  22. 22 The Param the Model Keeps Skipping: Required vs Optional Tool Parameters A model keeps omitting an optional 'currency' param and totals go wrong. The fix isn't a smarter prompt — it's the JSON schema. Here's why. Jul 24, 2026
  23. 23 Per-User OAuth Across Many Tenants: MCP Authentication at Scale A CCA practice question on per-user OAuth across tenants — why MCP centralizes auth instead of every tool re-implementing it inline. Jul 24, 2026
  24. 24 Where Does a Team Convention Live? Project CLAUDE.md Explained Project CLAUDE.md ships with the repo as shared team memory, while user CLAUDE.md is yours alone. The Claude Code memory hierarchy, explained with a CCA practice question. Jul 24, 2026
  25. 25 A Rule for You, Not Your Team: Local vs Shared Claude Code Settings Where does a personal Claude Code rule live so it follows you across every repo without landing in your teammates' checkouts? Jul 24, 2026
  26. 26 Instructions or a Hook — Which Runs Every Time? CLAUDE.md vs Hooks A CCA practice question on CLAUDE.md vs hooks: why an instruction is advisory but a PostToolUse hook guarantees the linter runs after every edit. Jul 24, 2026
  27. 27 Where Does a /review Shortcut Live? Claude Code Slash Commands Custom Claude Code slash commands like /review are markdown files in .claude/commands/ — learn the mechanism, the file tree, and why the other options fail. Jul 24, 2026
  28. 28 Slash Command or Skill? When to Use Each in Claude Code Model-invoked vs you-invoked: the mechanism that decides whether a capability belongs in a slash command or an Agent Skill. Jul 24, 2026
  29. 29 Run Claude Code in CI With No Human: Headless Mode Explained Wiring Claude Code into a CI pipeline to triage issues automatically? Learn why headless print mode, not the TUI, is the mechanism that makes it work. Jul 24, 2026
  30. 30 Allow npm test, Gate Destructive Git: Claude Code Permissions Scoped allow/ask/deny rules let Claude Code run npm test silently while destructive git still prompts. The mechanism behind Claude Code permissions. Jul 24, 2026
  31. 31 The Setting You Must Not Commit: settings.local.json in Claude Code Where personal, experimental Claude Code settings belong so they never land in a teammate's repo — settings.local.json, gitignored by default. Jul 24, 2026
  32. 32 Enterprise Denies, You Allow — Who Wins? Claude Code Permission Precedence Enterprise policy denies Bash, your local settings allow it — which one wins? The Claude Code settings precedence ladder, explained with a diagram. Jul 24, 2026
  33. 33 A Scoped 'Test-Writer' Agent: Custom Subagents in Claude Code Restrict a Claude Code agent to a few tools with a scoped subagent — where the file lives, what frontmatter does, and how delegation works. Jul 24, 2026
  34. 34 How Do You Guarantee Valid JSON? Forcing Structured Output Why 'return only JSON' in a prompt fails and forced tool_choice with a schema guarantees valid, parseable structured output every call. Jul 24, 2026
  35. 35 A Number Comes Back as a String: Validating Structured Output Types Extraction returns amount as '42' instead of 42. The fix isn't a downstream cast — it's a typed JSON schema plus a validation gate. Jul 24, 2026
  36. 36 Keep the Reasoning, Hide It From Output: Chain of Thought With Clean JSON You want Claude to think before it answers, but your downstream code needs clean JSON, not a wall of reasoning. Here's the pattern that gets both. Jul 24, 2026
  37. 37 Your Few-Shot Examples All Look the Same: Diversity in Few-Shot Prompting A CCA practice question on few-shot overfitting: why examples define the output distribution, and how to fix examples that are all one shape. Jul 24, 2026
  38. 38 Force the Tool, or Let It Decide? tool_choice Explained Why tool_choice:'tool' beats 'auto' when structured output isn't optional — the four modes explained with the mechanism, not the myth. Jul 24, 2026
  39. 39 Your Retry Loop Never Stops: Bounded Retries for LLM Output Why validation-retry loops must be bounded, and how feeding the error back into the next prompt turns rejections into self-correcting attempts. Jul 24, 2026
  40. 40 10,000 Docs Overnight, Cost Matters: Batch Processing LLM Jobs 10,000 documents, cost-sensitive, no latency deadline — the Message Batches API cuts cost ~50%. Learn when to batch vs call synchronously. Jul 24, 2026
  41. 41 It Ignores the Rule Buried in the Prompt: Where to Put Instructions Claude keeps skipping a rule buried in your system prompt? Learn why structure and position beat volume, caps, and repetition. Jul 24, 2026
  42. 42 'Unknown' Beats a Hallucinated Field: Preventing Made-Up Output Why a schema that forbids null forces Claude to guess. CCA D4 practice: allow 'unknown' in the schema instead of hoping it won't hallucinate. Jul 24, 2026
  43. 43 The Output Feeds a Program, Not a Person: Machine-Readable LLM Output Free text, Markdown, or JSON schema? When an LLM's output is consumed by code, not a human, the mechanism that makes it reliable. Jul 24, 2026
  44. 44 It Forgot Your First Instruction: Lost-in-the-Middle and Context Rot Why long agent runs ignore early instructions, and the mechanism behind lost-in-the-middle attention decay — plus the fix. CCA Domain 5 practice. Jul 24, 2026
  45. 45 The Task Overflowed the Window: Chunking and Decomposition A CCA Domain 5 practice question: an agent overflows the context window mid-task. The fix is compaction, not a bigger model — here's the mechanism. Jul 24, 2026
  46. 46 Stop Re-Sending the Same Big Block: Prompt Caching for Context A CCA practice question on prompt caching: why re-sending a fixed policy block every call wastes tokens, and how cache_control on a stable prefix fixes it. Jul 24, 2026
  47. 47 Why Is Your Cache Never Hitting? Prompt Cache Prefix Rules cache_read stuck at 0 despite adding caching? Learn the model-specific cache floor and why a too-short prefix silently no-ops. Jul 24, 2026
  48. 48 Where Did That Fact Come From? Grounding and Citations A CCA D5 practice question on provenance: why every fact an agent hands downstream needs a source attached, and what breaks when it doesn't. Jul 24, 2026
  49. 49 It Failed and Answered Confidently Anyway: Error Propagation in Agents Why a coordinator answers confidently after a subagent fails, the swallowed-error mechanism, and the fix: propagate and escalate. CCA D5 practice. Jul 24, 2026
  50. 50 When Should It Hand Off to a Human? Escalation Patterns A CCA D5 practice question on confidence-gated escalation: when an agent should hand off to a human, and why the naive answers all fail. Jul 24, 2026
  51. 51 Confidently Wrong: Confidence Calibration for LLM Output Why LLMs sound just as certain when wrong as when right, and how a confidence score plus a review/retry router fixes it. Jul 24, 2026
  52. 52 Your Scratchpad Vanished on Compaction: Persisting Agent State Why an agent's scratchpad notes disappear when context is compacted, and the fix: persist working state outside the window. CCA Domain 5 practice. Jul 24, 2026
  53. 53 80% History, 20% Task: Budgeting the Context Window Your agent's context is 80% conversation history and quality is dropping — why rebalancing the token budget beats a bigger model. CCA D5 practice. Jul 24, 2026