You could create mobile apps, informational web sites that generate Google traffic, niche SaaS services, a YouTube channel in a popular topic, sell physical goods on Amazon, open an Etsy store.
Ideas are the easy part, especially if you already have an expertise in some area. The hard part is the five years of building.
Here => https://www.indiehackers.com/businesses?revenue=Over%20%2425...
If you read their individual stories, you will find that 8 or 9 out of 10 started as a side-project.
Here => https://www.indiehackers.com/businesses?revenue=Over%20%2425...
If you read their individual stories, you will find that 8 or 9 out of 10 started as a side-project.
Also not all are 200K. But like OP says, if you have a $140K job and not having to work your ass off like the $200K jobs expect you to, then you can make the extra $60K in a well thought out and executed side-project.
Full of profitable side-projects => https://www.indiehackers.com/
You need
1) Discipline
2) A side-project that solves a "pain point" or atleast alleviates some of the pain in "pain point", so you can monetize from day 1
3) Ship, and refine.