[sidkshatriya]

What are the costs of a Ruby incompatibility just waiting to be discovered in production ? You can't assume you wrote tests to exercise every possible branch in every method in every object ?

The costs of static typing are reasonable as long as you're not using a fancy dependently typed language. Ask companies that are maintaining long running software -- types help. The investment is there in the beginning, the payoff is over the lifetime of the project.

If types are complex and poorly defined, you can change them ! The compiler will help you evolve your system through type errors. If you have a poorly structured program in a dynamically type language like Ruby then it becomes more difficult to evolve your system fast and with confidence. You're always asking -- have I missed something out ?

[jshen]

I've been writing software for a long time in many different types of languages. I've led many software teams for a long time that use different languages and tech stacks. I have not seen any measurable difference in productivity or defect rate across different languages. I have also looked at all of the research on this and it is inconclusive at best.

Ultimately, I think that choice of language is one of the least significant predictors of outcomes, yet it's one of the most debated and obsessed over.

Edit: I thought it would be helpful to give examples of what I think is more important. Good CI/CD practives, good observability, robust test and staging environments, etc have been far more important in my experience than static vs dynamic language choice.