Looks really cool! I'll definitely use this next time I'm looking for flights or just want to go somewhere random for cheap.
One bug(?) I found is that the return flights don't seem to be departing from the city I am travelling to. For example, it's showing me flights that go from X > Y, but then the return flight is Z > X instead of Y > X.
I'm working on a super simple way to monitor your API at an endpoint level - https://subbul.com/.
At work we spent a bunch of time implementing monitoring and alerting for all our APIs and I figured it would be nice to have a near plug-and-play solution, so I built exactly that.