# Martin Ferret

> TypeScript expert focused on type-checking performance. Contributor to TypeScript’s DOM types. Lead Content Owner for the JavaScript and TypeScript certifications at Certificates.dev. Based in France, working remotely across Europe.

Last updated: 2026-11-11. Every claim on this site links to a source.
Contact: mferret.pro@gmail.com

## Pages
- [Work](https://martinferret.github.io/work/): pull requests, issue analyses and answers in projects Martin does not own
- [Lab](https://martinferret.github.io/lab/): reproducible TypeScript type-checking performance experiments
- [Speaking](https://martinferret.github.io/speaking/): talks, workshops, podcasts
- [Invite me](https://martinferret.github.io/speak/): bio, talk abstracts, photo and contact for organizers
- [Timeline](https://martinferret.github.io/timeline/): every contribution, talk and experiment by date; machine-readable at https://martinferret.github.io/timeline.json
- [About](https://martinferret.github.io/about/)

## Metrics (as of 2026-11-11)
- 3 pull requests merged into Microsoft’s TypeScript repositories
- 5 pull requests opened at Microsoft
- 5 pull requests merged in projects I don’t own
- 2 pull requests in review right now
- 4 TypeScript projects contributed to
- 2 Lab experiments published with raw results

## Ledger
- 2026-11-09, Pull request, open: [microsoft/TypeScript-DOM-lib-generator#2592: Type WebAssembly.Memory buffers as ArrayBufferLike for shared memories](https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/2592)
- 2026-11-08, Pull request, merged: [microsoft/TypeScript-DOM-lib-generator#2583: Make Scheduler.postTask generic over the callback result](https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/2583)
- 2026-11-06, Pull request, merged: [microsoft/TypeScript-DOM-lib-generator#2582: Add a generic createElementNS overload for the XHTML namespace](https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/2582)
- 2026-11-06, Pull request, open: [microsoft/TypeScript-Website#3694: Document noUncheckedSideEffectImports fixes for CSS packages](https://github.com/microsoft/TypeScript-Website/pull/3694)
- 2026-11-06, Issue analysis, discussion: [microsoft/TypeScript#61460: InstanceType and constructor return type inference for built-in Error subtypes](https://github.com/microsoft/TypeScript/issues/61460#issuecomment-6683539096)
- 2026-11-05, Issue analysis, discussion: [microsoft/TypeScript-DOM-lib-generator#2566: MutationObserver.observe options should not be optional (follow-up)](https://github.com/microsoft/TypeScript-DOM-lib-generator/issues/2566#issuecomment-6664861293)
- 2026-11-03, Issue analysis, discussion: [microsoft/TypeScript-DOM-lib-generator#2439: Missing bounds in WebTransportReceiveStream and WebTransportSendStream parent types](https://github.com/microsoft/TypeScript-DOM-lib-generator/issues/2439#issuecomment-6614518879)
- 2026-11-03, Pull request, merged: [microsoft/TypeScript-DOM-lib-generator#2578: Make options required in MutationObserver.observe()](https://github.com/microsoft/TypeScript-DOM-lib-generator/pull/2578)
- 2026-11-03, Issue analysis, closed: [sindresorhus/type-fest#1285: Nullish / Nilable type](https://github.com/sindresorhus/type-fest/issues/1285#issuecomment-6617554050)
- 2026-11-03, Issue analysis, closed: [sindresorhus/type-fest#1315: DeepValuesOf](https://github.com/sindresorhus/type-fest/issues/1315#issuecomment-6617486103)
- 2026-11-03, Lab experiment, confirmed: [TypeScript Performance Lab #001: Typed events: the elegant type that slowed down every call site](https://github.com/MartinFerret/typescript-performance-lab/tree/main/experiments/001-typed-events)
- 2026-11-03, Lab experiment, open-question: [TypeScript Performance Lab #002: TypeScript 6 vs 7 on type-fest](https://github.com/MartinFerret/typescript-performance-lab/tree/main/experiments/002-ts6-vs-ts7-type-fest)
- 2026-11-01, Issue analysis, discussion: [microsoft/TypeScript-DOM-lib-generator#2574: AbortSignal.any should accept an Iterable<AbortSignal>](https://github.com/microsoft/TypeScript-DOM-lib-generator/issues/2574#issuecomment-6561832671)
- 2026-11-01, Answer, answered: [Stack Overflow: Why is the 2nd overload picked up?](https://stackoverflow.com/questions/80014081/why-is-the-2nd-overload-picked-up/80014150#80014150)
- 2026-10-20, Workshop, delivered: Pizzeria del Compilator: Building a Type-Safe Configurator with TypeScript (Frontend Nation 2026, TypeScript Day)
- 2026-08-06, Pull request, merged: [spring-projects/spring-amqp#3549: Add batchSize and batchReceiveTimeout to @RabbitListener](https://github.com/spring-projects/spring-amqp/pull/3549)
- 2026-07-28, Pull request, merged: [spring-projects/spring-amqp#3528: Document PooledChannelConnectionFactory sizing](https://github.com/spring-projects/spring-amqp/pull/3528)

## Elsewhere
- https://github.com/MartinFerret
- https://linkedin.com/in/martin-ferret
- https://medium.com/@ferretmartin91
- https://sessionize.com/martin-ferret
- https://github.com/MartinFerret/rendez-vous-typescript