I remember my time doing Ruby was really informative about testing and languages in general.

The Ruby community was really great at doing automated testing and it's actually where I really cut my teeth on testing, but if you go back and look at the tests you'll find heaps of them are testing and checking types for functions. It almost felt like people were building static typing using automated tests.

Some people bang on about static typing getting in the way of agility, but the reality is that you either end up spending the time creating extra tests, or you end up cutting corners and creating unreliable software which you'll spend a lot of time troubleshooting down the road. You end up paying a big price to save a marginal amount of time at the start of a project.