I run three different saas products as a solo. Here’s some things I’ve picked up:

Some things can be simpler when there’s only one of you. Take those opportunities when they arise.

You don’t need remote CI when there’s only one dev. Just make running the test suite part of your deploy script.

Use hosted services. Sure it would be cheaper to rent a server from OVH and do it all yourself. You don’t have time for that. You’re saving money on staff, spend a little on a hosted database, k8s, etc.

I love Google Cloud Run. Love it. Seamless deploys, dead easy rollbacks, inbuilt secret management, etc.

Micro services are about scaling teams, not technology. You’re a team of one, that’s probably the number of services you should have.