I suggest reading the article. The reason they haven't chosen "boring" tech has nothing to do with the clients running their software and everything to do with their internal development experiences.

> MySQL (or PostgreSQL) would come next. I’m not particularly familiar with anything MySQL post 1998, but I’m sure it would work. The HA story for open source databases is somewhat surprising, though: you can either have traditional lagging replicas, or commit to no-primary-replica clusters that have very surprising transaction semantics. I wasn’t excited about trying to design a stable API or good network graph calculations on top of those semantics. CockroachDB looked very promising, and indeed still does! But it’s relatively new for a database and I was a little concerned about getting attached to features in a fresh DBMS that would be hard to migrate away from if we needed to.

The reason they are ruling out products isn't "this won't work where it runs" its "I don't like this". They talk about worrying about network graphs and proceed to use SQLite and copy garbage around.

If you're dinging them for not using Cockroach, they explained why they're not using Cockroach in the exact paragraph you quoted: if they use Cockroach, they're committing to the scaling and distribution system that Cockroach provides, which might or might not be a good fit for them 2 years from now. If it isn't a good fit, they're stuck with a huge engineering bill to get themselves out of Cockroach.

We're moving towards sqlite for things for the same reason. sqlite is simple to reason about. The distributed state problem not simple, but our distributed state problem is not Tailscale's and theirs isn't yours; every distributed state problem is unhappy in its own way. As they work out the contours of their specific distributed state problem, sqlite isn't the component that's going to break down.

> If it isn't a good fit, they're stuck with a huge engineering bill to get themselves out of Cockroach.

Similar to the current engineering bills they are paying because they switched from a json file -> etcd -> sqlite?

Seems like the cost of switching isn't really an issue for them since they've pulled that lever multiple times now.

It does seem that way. Keep thinking along those lines. You're almost there!