~/talk

So you've decided to do a technical migration...

on YouTube 31m
Talkat Nordic.js 2025 · 2025-10-02..10-03· [frontend-architecture, typescript]

speaker

name:Sophie Koonin
website:https://localghost.dev

resources

video:https://youtu.be/a1BqYqLoVWU
slides:none on file

summary

A TypeScript migration at Monzo takes just over two years and concludes in December 2023, moving from Flow and Babel to the new Next.js compiler and TypeScript. The team builds a package generator, writes a packages ready to migrate script and reuses Stripe’s migration code, posts a dashboard percentage (97 98 99) and enforces CI checks. Outcome is tangible: faster compiler and IDEs, fewer crashes, some rollbacks and bug fixes, and the old Flow toolchain removed.

AI-written summary · about

chapters (12)

  1. 0:00Introduction
  2. 3:14TypeScript over Flow
  3. 5:19Experimental migration
  4. 8:09Team structure & strategy
  5. 10:58Tooling for TypeScript
  6. 13:27Progress & milestones
  7. 15:10Slow progress & deadlines
  8. 17:39Stakeholder buy-in
  9. 19:45Risks of incomplete migration
  10. 22:38Final push & success
  11. 24:22When to migrate
  12. 30:59Q&A

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