When I realized I spent 2.5 years migrating an AngularJS application to Angular (among other things), I thought it would be worth telling the story.

The aim of this text is not to present in detail the technical challenges we met nor the solutions we chose, but to explain the journey we undertook while replacing every single line of code in our application codebase.

My idea is to share the mistakes we made, the pitfalls we fell into, and the advice I can give to anyone who is about to begin such endeavor.

To give you an idea of the application size, our github repo counted

118'030 lines of code

1'706 files

in the application src/app folder (typescript, html and scss files included) rightafter the migration was completed.