I'm increasingly boggled by how much time we spend discussing how to write new code, when the majority of engineering time is spent analyzing existing behavior + reading existing code. Replay is one of the most innovative tools in the space of code-reading that I've seen in a while.
The time-travel debugging on its own would make an excellent product, but the team didn't stop there. They put tremendous effort into going the extra mile and making the collaborative / narrative building very smooth and natural so that the tool would be useful to share with designers, PMs, and anyone else interested in testing the user experience of a product.
I've been following the Replay team since late winter 2021, and very excited to see that this is finally generally available!
By granting the power to inspect your app behavior in the context of the source code without making you wait for code to recompile, Replay is an ideal power-tool for learning how a system works. I look forward to the day (10 years out?) when this style of debugging is natural and available to every mainstream programming language.