Converting an app that started per-client deploy, single-tenant, cloud-ignorant and mono-node to multi-tenant, multi-node, cloud storage and a cluster of a few nodes.
On one hand, I regret not having thought it could find a market and I now have to do this and plan a migration.
On the other, I saved a lot of time going to customers instead of building the boring side first... So I don't know what to think of it.
I find that most of the development work is now "ops" instead of user-facing features (either addition, removal, or polish) and am a bit perplex at this.