For a professional developer, coding would indeed be the easiest part.

Its is and it isnt - the problem for a professional dev/engineer is that you want the best technical solution instead of releasing some cobbled together rubbish as quickly as possible

"the problem for a professional dev/engineer is that you want the best technical solution instead of releasing some cobbled together rubbish as quickly as possible"

Yes, but have you tried to optimize for code size, clarity and speed of creating features rather than just technical completeness. As a single dev there is an incredible amount of corner cutting you can do which you can polish away once the product gains traction. You can hack stuff together just as long you know how it's supposed to be properly built and how you get there from the rapid prototype.

It's actually easier to do this as a single dev because you typically have a near-complete mental model of the software, including the rough bits and areas for improvement.

With a team of 4 people it's very easy for no one dev to have a complete mental model, which leads to nobody truly understanding the weak points underneath.

When you say "you want", generally that's because you have a full time job, and don't want to spend your free time doing the same as work.

Either you do quick hack because you want to play. Or you design nice stuff because you have to do something exceptional.

If you want passive income, you need to get out of that mentality. After work is still work, except you are the employer.

since you already tried this out. Were your projects similar to other services or they were completely new ideas?

I am wondering if it is easier to launch in a proven market and get a small portion of the pie rather than create a new idea that might end up not working out.

Generally sport related - but pushing technology. The problem was there was no market - in a few instances markets were established later but I had left by then. The upside is i can still trade on tech skills

Its a paradox of I can build anything, so why cant I build something that makes money

option 3: go after a niche in a proven market and rule that (i.e.: a beachhead market). After that expand.

Obviously that's the best option but finding that niche might still mean you have to create an mvp and jump through all the hoops multiple times to validate it.