Parallel Session Efficiency

Running multiple Claude Code sessions simultaneously multiplies your throughput but also multiplies your token spend. The efficiency optimization is minimizing redundant context loading across sessions. If three sessions all read the same ten files, that is thirty file reads instead of ten. The fix: structure your parallel work so each session reads different files.

The task decomposition from earlier directly enables this. Session A works on the auth module and reads src/auth/. Session B works on the API routes and reads src/routes/. Session C works on the database layer and reads src/db/. Each session reads only its own domain. The shared context — project identity, conventions, architecture — comes from CLAUDE.md, which is loaded once per session at near-zero marginal cost because it is the same file. The domain-specific context is loaded on demand per session.

1. 1. Partition by Domain Each parallel session owns a domain: auth, API, database, frontend. The domain determines which files the session reads. No overlap means no redundant token spend.
2. 2. Share via CLAUDE.md Cross-cutting concerns — naming conventions, type patterns, error handling standards — live in CLAUDE.md. Every session loads them once. No redundancy, consistent behavior across sessions.
3. 3. Coordinate via Branches Each session works on its own git branch. Merge when all sessions complete. If sessions need to share a new type or interface, one session creates it and the others pull after merge.