How to make side income of 500-3k$ a month as a CTO?

If you have been a CTO/cofounder for "many years" and it is not matching your desired income, then you should not have free time.

The company I work for has an opportunity available that might be a good fit for you -- we specialize in conducting remote technical interviews as a service. It pays pretty well & the work is very flexible. We have some folks who work full time on our platform, and some who only do 3-4 interviews per month.

Feel free to reach out, email is in my profile.

Maybe consultancy to other companies? Lots of startups don't have a highly skilled CTO at the start of their venture. But I'd say try to figure out how to grow your business since it's been running for some years and I assume it's worth investing in?

Can you not do something with that time that enables your business to grow and pay you more?

Pick a product you think/know you could build better (as in, there's already a market), and just keep shipping.

I'm at about 4.4k USD total revenue after running https://onlineornot.com for about 13 months now.

I work 2 hours a day before work (had a 9 month streak going at one point), and it's extremely fun.

Build something you’ll use, instead of something you’ll sell. This way you are successful at once, and possibly more if you also sell it.

Recommendations: - A machine to clean a facility. - A tool to scan a car for maintenance assurance; use common cathode technology (CRT)! - The manner of activating an electric outlet in your house to cause application of force; if you can make a wave that resembles an object in two places it will move to the point of least resistance. Object is sphere, example: 2pi-related, and now a sin(x) function is symmetried by aligning subsequent waves with the connected “tissue” of the sphere in a pair of positions, imagining a rate of motion where no two adjacent points are indistinct—you’ll need the graph to resemble an oval.

You could also build your own cloud product, seeking to replace AWS, etc. Follow the “rule of 3,cloud-centered computing”: 1) all data input is data to be crunched, on cloud-hardware, to keep any distinction of “trusted” and “not trusted” minimum, 2) create a valuable change on the data, could be anything: run-as-python3, find-min-and-max-then-divide, rasterize-in-3-D-simulation, etc, this is sold by the kilobyte, megabyte, millisecond, 10-minutes, etc, 3) all data you receive must leave the system at the end of the compute period, no security threats of code or logs etc that stick around! Even storage is billed by the kilobyte/normal complexity and all the data leaves if billing is turned off. Keep all recorded account actions on a tabular-setting computer, or “virtual machine”. This includes billing logs: “10:02 pm EST, 5 min compute” and other useful customer details: never reuse the cloud-system for keeping persistent information though, example: MachineA has InterfaceA, and all data that arrives is crunched then returned, is encrypted, log-in by API-key, and costs money to use. InterfaceB is a local-only network with MachineB-InterfaceC, for billing. Has a web-port, server, database, and is web-facing on InterfaceD, InterfaceA too only.

Hope this helps! Enjoy.

I decided to reimplement every cloud service that any of my business partners use. Public clouds are beyond ridiculously overpriced. And their availability is shit. So you might as well pocket the 95% profit margin between renting cheap bare metal servers and selling cloud APIs. I've never seen a ZFS RAID die. But I could fill an evening with S3, EBS, Gdrive, Heroku horror stories.

Job hop. Otherwise, maybe look at the other side of the equation and adjust your expectations.

Quit and get a job at a FAANG?

Crypto farming / liquidity providing. 50%-100%/yr.

$3K/mo = $36k/yr = put $75K in passive yielding to get above. Nothing else to do to achieve that.