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# Oh CommonJS! Why are you mESMing with me?


- **Date:** Thursday, Jul 18, 2024
- **Time:** 12:10–12:40 (30 min)
- **Room:** STAGE 10 (120)
- **Event:** World Congress 2024

## Recording

[Watch recording](https://www.wearedevelopers.com/videos/1059-oh-commonjs-why-are-you-mesming-with-me)

## Description

Typescript is almost everywhere. It's so established that we use the ESM syntax subconsciously. Even though we might think it's safe to use Typescript, we must remember that the browser and NodeJS server don't understand TS out of the box, especially for library maintainers. That is why we use bundlers. But what if their output is different from what we expected? Should we care and trust still? I came into a situation where CommonJS and ESM messed with me. I will also share my thoughts on the interoperability challenges between packages and how to overcome them.

## Speaker

### [Jolo](https://www.wearedevelopers.com/@jolo)

Fullstack developer with a knack for whipping up code recipes using my secret ingredients: a dash of JavaScript, a pinch of Python, and a whole lot of serverless magic


## Related talks at this congress

- [Bun: the all in one JS toolkit](https://www.wearedevelopers.com/events/world-congress-2024/sessions/236-bun-the-all-in-one) — Wendelin Peleska
- [Tree Shaking the Bytes Away](https://www.wearedevelopers.com/events/world-congress-2024/sessions/363-tree-shaking-the) — Francesco Novy
- [How AWS Generates Polyglot Libraries Based on a Single TypeScript Codebase](https://www.wearedevelopers.com/events/world-congress-2024/sessions/235-how-aws-generates) — Markus Ziller
- [Write once, use anywhere: Framework agnostic Design Systems with Web Components](https://www.wearedevelopers.com/events/world-congress-2024/sessions/354-write-once-use) — Sascha Lehmann