What a system does when a part of it fails is the whole job.
I am a computer engineer. I do not trust a happy path: everything you build eventually meets a bad input, a dropped connection or a service that stops answering, and the design is judged on what happens then.
Software is the same argument with faster feedback. A supplier does not pick up. A market feed stops mid-day. A listing disappears while you are reading it. Most of the work in the products here is what happens in those moments, and almost none of it is visible on a screenshot.
I build alone, which decides a lot for me. It rules out anything that needs a team to hold up, and it rules in the things one person can finish and keep running. Artificial intelligence changed that line — work that used to need a department is now something a single engineer can ship.