Understand Legacy Code
Change Messy Software Without Breaking It.

Types at the edges of your system

Find and fix your TypeScript blind spots

😃 Coding with TypeScript feels safe, the compiler has your back.

😨 But today, you got a critical issue in prod: payments are failing! A quick check of the logs left you puzzled: TypeError: discount.toFixed is not a function.

😕 Wait… Isn't discount supposed to be a number here? How did that happen? Why didn't TS catch it before?! Worry no more.

🤠 In this talk, I will show you where your blind spots are, and a simple way for you to fix them.

Mazda head units got bricked by a local NPR station in Seattle in February 2022. Better validation at the edges would have save them a lot of trouble (and money).

🧰  Resources

Nicolas Carlo

Written by Nicolas Carlo who lives and works in Montreal, Canada 🍁
He founded the Software Crafters Montreal community which cares about building maintainable softwares.