To be honest, I'm not sure I can recommend anything specific here.

1. How much data do you have and how many entries? If you have lots of data with very small records, you might need an off-heap based cache solution. The only ready-made implementation I know is Olric [1].

2. If you can use an on-heap cache, you might want to look at groupcache [2]. It's not "blazingly-fast", but it's battle-tested. Potential drawbacks include LRU eviction and lack of generics (meaning extra GC pressure from using `interface{}` for keys/values). It's also barely maintained, though you can find active forks on GitHub.

3. You could implement your own solution, though I doubt you'd want to go that route. Architecturally, segcache [3] looks interesting.

[1]: https://github.com/olric-data/olric

[2]: https://github.com/golang/groupcache

[3]: https://www.usenix.org/conference/nsdi21/presentation/yang-j...

Otter can be used as the backing store with groupcache-go, which is a fork of the original groupcache: https://github.com/groupcache/groupcache-go#pluggable-intern...