Developer-facing manual covering:
1. Architecture overview with the four-layer data flow diagram
2. Repository layout (src/, snapshot/, storage/, etc.)
3. Dev environment setup (one-time + daily) and the
'what to restart after what type of change' table
4. Common commands quick reference
5. Debugging: backend (server logs, curl), frontend (browser
DevTools, console.log diagnostic points, React/Lumino
inspection), and end-to-end symptom -> cause table
6. Packaging and release (PyPI wheel via hatch + jupyter-builder,
version sourced from package.json, git tag flow, CI)
7. Known pitfalls: jest+pnpm linker incompatibility, S3 strong
consistency variance, conda/npm gotchas
8. 5-minute quickstart for new contributors
User-facing concerns (install/config/troubleshoot) stay in README.md;
design goals stay in design.md; AI coding rules stay in AGENTS.md.
DEVELOPER.md slots in for engineer handoff / onboarding.
Co-Authored-By: Claude <noreply@anthropic.com>
