Go file walk implementations have radically different performance characteristics. In 2021 the native implementation has improved so much, you don't need anything else.

Memcached and Redis. More different than first appearances would suggest. From how they use memory to how they expire items, the differences are not as subtle as you would expect.

Recurring revenue is considered the holy grail for any technology business with SaaS being the main way to achieve this. In 2021 while more people are using the internet than ever, building your SaaS it's harder than ever.