Claude Code Best Practices (Boris Cherny)

Verification: The Quality Multiplier

"Give Claude a way to verify its work. If Claude has that feedback loop, it will 2-3x the quality of the final result." -- Boris Cherny

Always give Claude a way to validate its work:

Complexity	Method	Example
Simple	Bash command	npm run lint, npm run typecheck
Moderate	Test suite	npm test, pytest, go test
Complex	Browser/Simulator	Playwright, Chrome DevTools, mobile emulator

Integration: PostToolUse hooks (auto-format, type-check, lint), PreToolUse on commit (mandatory tests), QA agents (/qa:qa-audit).

Recommended Model

"I use Opus with adaptive thinking for everything." -- Boris Cherny

Context	Model	Rationale
Complex tasks	Opus 4.7	Most advanced reasoning, adaptive thinking, 1M context, xhigh effort
Audits and analyses	Sonnet	Good speed/quality balance
Simple tasks	Haiku	Fast for trivial operations

Advanced Prompting

Avoid	Prefer
"Fix this bug"	"Fix the null pointer in getUserById when user doesn't exist"
"Make it better"	"Reduce the time complexity from O(n^2) to O(n log n)"
"Add error handling"	"Add try/catch for network errors with retry logic (3 attempts, exponential backoff)"

Techniques: "Grill me on these changes", "Prove to me this works", "Knowing everything you know now, implement the elegant solution".

See docs/guides/PROMPTING-GUIDE.md for the complete guide.

Effort Levels

Match the level of reasoning to the task.

Task	Effort	Why
Exploring code, reading files	low	No need for deep reasoning
Implementing a standard feature	medium	Speed/quality balance
Designing an architecture, audit, complex debug	high	Deep reasoning required
Critical system architecture, advanced security audit	xhigh	Maximum reasoning (Opus 4.7 required)

Command: /effort low, /effort medium, /effort high, /effort xhigh (interactive slider).

Automatic Memory (CLI 2.1.76+)

Claude Code automatically remembers preferences, decisions, and project context in ~/.claude/memory/.

Memorize (auto)	CLAUDE.md (git)	Rules (auto-activated)
Personal preferences	Project conventions	Per-language rules
Architecture decisions	Mandatory workflow	Code patterns
Team context	Documentation references	Verification checklist

Do not duplicate: if it is in CLAUDE.md, no need to memorize it. Use "remember that..." to force an explicit memorization.

Parallel Sessions

"The single biggest productivity unlock." -- Boris Cherny

Use git worktrees for 5+ Claude Code sessions in parallel. See the git-worktrees skill for details.

Context Management

Situation	Action	When
Long session, intact context	/compact	Between phases (Explore → Plan → TDD)
Total topic change	/clear	New unrelated task
Normal session	Let it be	Auto-compaction if needed

Quick Recovery

If a refactoring breaks everything: /rewind (or /undo, equivalent alias) returns to the last stable state. Faster than git stash or git checkout. Checkpoints saved automatically before each modification.

Session Resume

/recap generates a summary of the current session — decisions made, files modified, work state. Useful to resume a session after a break or a /compact.

Situation	Action
Return after a break	/recap to recover the context
After /compact	/recap to verify what was kept
Onboarding on an existing session	claude --resume <id> then /recap

Configurable via /config (enable/disable automatic recap on resume).

Token Optimization

Prompt Caching 1h (CLI 2.1.108+)

The ENABLE_PROMPT_CACHING_1H variable enables a 1-hour prompt cache instead of 5 minutes. Significantly reduces costs for long sessions.

Enable in .claude/settings.local.json:

{
  "env": {
    "ENABLE_PROMPT_CACHING_1H": "1"
  }
}

Compatible with API key, Bedrock, Vertex, and Foundry. Alternative: FORCE_PROMPT_CACHING_5M to force the 5-minute TTL (useful if telemetry is disabled).

RTK (optional)

Reduce token consumption by 60-90% with RTK.

Installation: brew install rtk. The foundation includes a PreToolUse hook that automatically rewrites commands. Disabled by default, enable with ENABLE_RTK=1 in the env section of .claude/settings.json or .claude/settings.local.json.

rtk gain to see the savings. rtk discover to find unoptimized commands.

Quick Command

/work:work-commit-push-pr "description" -- commit + push + PR in a single command.