For a non-strong-typed language, it's difficult to dive into the code after you haven't work on that codebase for a while.

We were on a really old Mongoid (or carrierwave, or some other gem, can't remember), It was difficult to find the right methods to use and etc.

I understand it was our own fault not to write comprehensive tests or keep all gems up-to-date.

But a dynamic typing language is a lot more "punitive" when we aren't writing perfect code, using perfect design, and/or exercising perfect engineering practices.