>How do you have the energy to work after-hours?
I use tools that do the work for me, and charge way more than I deserve. Money is a great motivator. Machine learning work also involves a lot of waiting (training models, deploying code, etc.), so I line up my gigs while I'm at the office.
>What do you dev?
Full stack with JHipster. It's a command-line tool that writes a CRUD app for you. Front end in Angular, back end in Spring.
All you need to do is define a data model (which you can typically do in a night), and change the user-facing parts of the website to look however your client wants. This gets much easier if you have your client write copy, and give them a selection of open-source CSS themes to choose from.
I usually spend about twice as long in client meetings as I do actually programming.
>Bonus: How do I get into this?
Sell your skills to boomers who can't into technology. They won't have a use case in mind, so suggest one. The easier to set up, the better.
My last client was a middle-aged dentist who needed a website. All he wanted was a way for customers to make and edit appointments. The app had 2 entities (user & appointment). All I had to do after generating it was (1) change the user permissions so a user could only create or edit appointments for himself, (2) create a UI that looked like a calendar, and (3) create pages that displayed appointments for a given day, week, and month.
Took about 20 hours, 2 a night for 2 weeks. At $5000, that's $250 per hour. And since there's hardly any features, I know he'll call me later and ask for more.
Pro tip: charge by feature, rather than by hour.