I still don’t get why people try writing their own data store, especially in a language that's simply not very well suited to that task (and we're an almost 100% Golang shop here). Seems to be a rite of passage.
The requirements are literally <100LOC of wrapping an HTTP interface around Redis with using TTL - which has been battle tested for years and is both rock solid and ridiculously fast.
Public service announcement: Don't write your own data store. Repeat after me: Don't write your own data store, except if you want to experimentally find out how to build data stores. It's arbitrarily hard and gets even more so at every layer. Plus, you leave behind an unmaintainable mess for the people after you. There's already a great OSS data store optimized for every use case and storage medium I could possible imagine.
[1]https://github.com/coreos/etcd [2]https://github.com/cockroachdb/cockroach [3]https://github.com/influxdata/influxdb