[locknitpicker]

> Not sure where you heard this but general sentiment is the opposite.

My personal experience and anecdotal evidence is in line with this hypothesis. Using the likes of Microsoft's own Copilot with small simple greenfield TypeScript 5 projects results in surprisingly poor results the minute you start leaning heavily on type safety and idiomatic techniques such as branded types.

> There was recently a conference which was themed around the idea that typescript monorepos are the best way to build with AI

There are also flat earth conferences.

[conartist6]

It's especially tricky since monorepos are an obvious antipattern to begin with. They're a de-separation of concerns: an encouragement to blur the unit boundaries, not write docs, create unstable APIs (updating all usages at once when they change), and generally to let complexity spread unchecked.

[miguelspizza]

Hate to say it but this sounds like a skill issue. The reason Typescript monorepos are gaining popularity for building with AI is because of how powerful TS's inference system is. If you are writing lots of types you are doing it wrong.

You declare your schema with a good TS ORM then use something like TRPC to get type inference from your schemas in your route handlers and your front end.

You get an enforced single source of truth that keeps the AI on track with a very small amount of code compared to something like Java.

This really only applies to full stack SAAS apps though.