I wouldn't call myself an expert in this. There are plenty of creators with many successful micro SaaS apps.

However, I've spending a lot of time lately trying to learn how to build one for myself as a hobby. Doing this from a background in big tech (I work for Microsoft, so as big as tech gets). I made a lot of mistakes, so my goal today is to save you the dozens of hours I wish I could've saved when I started out.

Ignore Scale

At this stage, thinking about building something scalable will likely result in you going a lot slower than you otherwise probably could. You're in a hacking stage at this point. Validating your idea is way more important than scaling right now. I've had to throw away hundreds of line of really well written code because the feature wasn't bringing much value.

Don't Optimize for COGSs

COGS (or Cost of Goods Sold) is what makes big tech companies fine tune cloud service architectures to the max. You don't need that complexity. I lost way too many hours fine tuning things in Azure and even when I had them working I still ended up migrating my SaaS app to Vercel.

Keep a Lean Backlog

You're get used to many people having agendas when you are in big tech. Everyone has their pet project that hope will get them promoted and that results in bloated backlogs. Keep yours clean. It's fine to have ideas, but try to boil them down to the most important problem you're solving.

Best of luck with your new SaaS app. Looking forward to using it!