Visual Studio Code is a perfect editor for TypeScript, but it doesn't support project-wide type-checking out of the box. Luckily, you can add it to your own TypeScript project.
REST is a great framework for building APIs, but it doesn't cover everything you need for success. Consider what can go wrong and you'll do much better.
Formal code reviews lead to confusion and wasted time. Pair programming, on the other hand, has regular, effective code reviews built into its framework.
Your mocking library might be trying to make things easy for you by letting you use mocks without defining their behavior—but it's really sabotaging you.