> Do you even need a database?

Then proceeds to (poorly) implement database on files.

Sure, Hash Map that take ~400mb in memory going to offer you fast lookups. Some workloads will never reach this size can be done as argument, but what are you losing by using SQLite?

What happens when services shutdowns mid write? Corruption that later results in (poorly) implemented WAL being added?

SQLite also showed something important - it was consistent in all benchmarks regardless of dataset size.