sonder-server-decomposition-campaign

Pick a bounded, pure helper with few callers, create a packaged module in the correct layer plus a boundary test, rewire server.py with an underscore alias import, then run the architecture checker, compileall, and pytest gates before documenting and committing the slice.

A WP1 slice is one small, behavior-preserving increment of the strangler migration that moves a cohesive responsibility from a root module into the sonder_runtime package. Each slice is proven by gates, documented in a WP1-<ORDINAL>-SLICE.md file, and landed as a single commit.

Choose by what the code does: pure policy goes to domain, use-case wiring to application, sqlite/subprocess/network I/O to adapters, environment and config to platform, and protocol translation to interfaces. The check_architecture.py script enforces these edges with specific violation messages.

The checker builds its inventory from git ls-files and fails closed with a RuntimeError if a tracked file is deleted without staging. Stage the deletion with git rm or git add on the exact path, never git add -A, then rerun the checker.

Do not use it for questions about why the architecture rules exist or which document is authoritative (use sonder-architecture-contract), for general commit and CI gate mechanics (use sonder-change-control), or for debugging runtime failures (use sonder-debugging-playbook).

No. Slices are behavior-preserving by definition: no new environment reads, no import-time side effects, no output changes. If you find a bug during the move, record it in the slice doc and fix it in a separate commit after the slice lands.