Lesson 3.4Lesson 16 of 30
Plan mode vs direct execution
Determine when to use plan mode vs direct execution
Key points
- 1Plan mode is for large, multi-file or architectural work and for tasks with several viable approaches: splitting a monolith into services, a 45-file library migration, choosing between two integration designs.
- 2In plan mode Claude reads and searches but does not edit until you approve the plan. Mistakes in the approach are cheap to fix before 30 files have changed, not after.
- 3Direct execution suits clear, well-scoped changes: a single-file fix with a stack trace pointing at the line, or adding one validation check. Planning these only adds delay.
- 4The Explore subagent runs verbose discovery (Grep, Glob, Read over hundreds of files) in its own context and returns a short summary, so the main session keeps room for the later phases.
- 5Combine them: investigate and agree on the approach in plan mode (Shift+Tab or
--permission-mode plan), then implement the approved plan with direct execution.
What the exam guide checks here
Objective wording from the exam guide (English).
- 3.4.K1Plan mode is for large-scale, multi-approach, architectural, multi-file work
- 3.4.K2Direct execution suits simple well-scoped changes
- 3.4.K3Plan mode allows safe exploration and design before changes, preventing rework
- 3.4.K4Explore subagent isolates verbose discovery and returns summaries
- 3.4.S1Select plan mode for architectural tasks (microservices, 45+ file migrations, integration choices)
- 3.4.S2Select direct execution for clear-scope changes (single-file fix with stack trace)
- 3.4.S3Use Explore subagent to prevent context exhaustion in multi-phase tasks
- 3.4.S4Combine plan mode for investigation with direct execution for implementation
Lock it in
Answer scenario questions on this topic. Every option comes with an explanation.
Practise 3.4 · 21 questions