When I started to develop Tolgee for my master thesis about 2 years ago, one of my goals was to provide a localization tool also for developers who would like to use it locally on their machine.
Things were different those days. Tolgee was named Polygloat and the tool was intended to be simplest as possible. So I wanted to keep the tool small, and I didn't want to make users to run separate database server for it. But I also wanted to run the app in cloud, where Postgres is considered "more production ready" choice.