One version to break them all: How to prevent a wrong version breaking your micro frontends

“Oops, it turns out my PR was actually a breaking change. I'm so sorry I broke production for all apps except ours”. This developer nightmare was the worst case scenario the team at Postman has solved.

For weeks Patrick and colleagues pondered how to set up their Monorepo with Module Federation in such a way that dependencies can be shared, in order to deploy micro frontends independently and with confidence.

This talk will focus on how shared dependencies can keep federated apps small in bundle size, but come at the risk of breaking other apps when semantic versioning (SemVer) is not adhered to.

Various solutions to this problem will be discussed:

• The single version policy for integrated Nx repos
• The complete autonomy policy for package based Nx repos
• A hybrid option which can be summarized as single major version policy

The talk will discuss why Postman opted for the single major version policy, considering factors like migration efforts, release strategies, and differing levels of test maturity.

We will also cover how the team at Postman automated the detection of breaking changes in our internal libs, which prevents changes with the wrong SemVer to be deployed in production.