"Flight data is very dynamic, since the availability of flight seats and pricing information could potentially change every minute or even every second. The cached information could therefore go stale pretty quickly. Moreover, for any route, there can be thousands of possible flight combinations meaning the data size is huge."

"We did manage to reduce the overall latency with these improvements. But it still took more than a second to get the results end to end. We still wanted to improve it further, so we decided to go for an entire rewrite of the caching layer with the goal of …