Onboarding into a large codebase

Understand unfamiliar modules, data flows and dependencies, with links to the source.

The problem

New joiners and rotating teams struggle to understand large codebases, and legacy systems leave gaps in what anyone on the team knows.

What works today

In our internal prototype, inside our team only. It is not available to customers yet.

  • Codebase mapping explains unfamiliar modules, data flows and dependencies.
  • It writes architecture notes and onboarding guides linked to the source files.
  • The prototype also draws the codebase as a 3D structure you can look around.

What is planned

Targets, counted from the plan's first month, February 2027. They may move.

  • Team plans with shared tracesQ4 2027
  • IDE integrationsBy Q3 2028

Example: a first week on a billing system

Invented example. The team and the system are made up.

A new engineer joins an invented team that owns an old billing system. They ask Belay how an invoice is created. Belay answers with a short architecture note: the modules involved, how data moves between them, and a link to the source file for each step.

Illustrative

We are looking for design partners

5 to 8 engineering teams that work on large or legacy codebases.

Apply to be a design partnerEmail the founder