I'm talking about work that can be done one day per week on a weekend, or perhaps across a few evenings whilst maintaining a regular job.
Im interested in things that leverage a SWE skillset, as opposed to Uber or GrubHub type work, but also anything unexpected!
I recommendend asking your self “If I ALREADY had all of the money, what would I do?” and do that on the side instead.
I've been spending about two hours each morning on my own projects since 2017, it'll surprise you how much you can get done with consistent effort.
I have freelanced for a long time. Word of mouth and reputation generally attract the most quality new work. Since 2014 I have had an agency representing me, and they seem pretty good at finding customers and gigs.
Just look for a consulting group that doesn’t have 40000 job postings on LinkedIn
If you learn about SOC2 or something like that, then a "SOC2 fixer for linux boxes" is definitely something companies would outsource on a contract basis. SOC2 creates a tonne of temporary work (so they won't want to hire more people for it) that is specialist and distracting from the main development goals. The work might include things like creating evidence that a linux box meets various controls needed by an auditor. I think it would become a 90% knowing what tool/approach kind of job, and not deep thinking.
On the more speculative side, I think something that sysadmins have that most of us don't (most of us clicking around in the cloud) is a deeper knowledge of Linux, and knowledge of older tools that are better than the modern cloud equivalents - either cheaper, simpler, more reliable or less lock in. So if you are a knowledgeable "old man yells at cloud" type you could make some books/resources and sell them. This is a lot of work before money comes in because you need to write a book (no small feat ... but can be less than a published book - 40 pages is OK) and then market it. But simple Show HN, posing to reddits can get you going. Then write a blog where you have free tips, and share them occasionally as you post on forums when it is appropriate.
Bought two properties and already renting one out... in preps to get the other rented out soon, and then there's my house... already have some interest in that as well.
People might be looking for something on your tech stack.