[siliconc0w]

A big one is keeping iteration times fast.. If you have to wait more than a few minutes to run through your test suite or deploy to a dev environment it really kills the momentum. It starts easy but as you add complexity, dependencies, slow or flakey tests, it is slowly gets eroded.

[Hamuko]

It takes over 30 minutes to run the entire test suite for our application on my local machine. Thankfully you can get it for under 20 minutes if you push it and have the CI test it for you.

[bluefirebrand]

Yep. My unit tests at work take 10 full minutes to run lately

It probably costs 30+ minutes of productivity every time I run them