B2B SaaS

B2B SaaS: From MVP to a Platform the Team Can Extend

Software Development, Quality Assurance

Challenge

The product started as a proof of concept and grew feature by feature. Each new request took longer than the last, and nobody could say which parts were safe to change.

The early code had done its job: it proved the idea and won the first customers. But it was never built to carry a growing product. Business rules were spread between the front end and the API, the same logic lived in several places, and there were almost no automated tests. Every release depended on manual checks by whoever happened to know that part of the system.

The in-house team had customers waiting for new features, so stopping for a full rewrite was not an option. They needed a codebase they could extend with confidence — without pausing the roadmap to get there.

Solution

We restructured the codebase around clear module boundaries, added automated tests around the flows customers use daily, and introduced review and release practices the in-house team could keep running.

The work ran alongside regular feature delivery rather than as a separate project:

Mapped the product into domains and moved shared business rules into one place per module, one area at a time.
Put automated tests around the customer-facing flows first, so every refactoring step was checked against real behaviour.
Used TypeScript types as the contract between the front end and the API, so breaking changes show up at build time instead of in production.
Agreed code review guidelines and a predictable release routine, and paired with the in-house developers so the practices became theirs, not ours.

Results

New features ship without a rewrite each time, and the areas that used to break silently are now covered by tests the team maintains itself.

Developers can see which parts of the product a change touches before they start.
Releases follow the same routine every time instead of depending on who is available.
The in-house team owns the tests and the review process and keeps extending both as the product grows.