What hobbies do you practice that is other people's professions?

I write software for fun and give it away. I also write software for money and don't give it away.
- 🤘 Ditto!
- Good man!

So many
Homelab
Buy broken electronics, repair, resell (so like microsoldering, diagnosing, etc)
Woodworking but I’m bad at it
Cooking
Music but I’m bad at it
3d printing/cad but I’m bad at cad
Language study 日本語
Pcb design and some coding related to this but I’m bad at it
It’s why I get the anti work people. If I could change careers every few years I would. I love learning about new stuff. I post a lot but most of the time I do that is either when I have idle time at work, before or right after work (although sometimes it leaks into weekends). I hate the phrase jack of all trades master of none, it’s cool to know about a lot of things (as long as you recognize the limitations of your knowledge)
- I recently learned that the full quote goes like this: "Jack of all trades, master of none, though oftentimes better than master of one." Thought that might reconcile you with the phrase :)
- You can also be a jack of all trades, master of some. Or a lot. Or most. 🤝
  
  Or, you can be, Abserd!
- it doesn't matter whether you're good at it or bad at it. As long as you enjoy what you do, that's all that matters :)
- Does 日本語 mean "I'm bad at it"
  
  Ha no, it means Japanese (or Japanese language). The kanji would be pronounced “nihongo”

Fixing bikes. But if I had to do it for a job, under time pressure, I'd hate it. Give me all afternoon to fix a bike and let me put on a 5 hour podcast about the collapse of the Aztec empire, that's my happy place
- I would like to know which podcast covers the fall of the Aztec empire for 5 hours. Asking for a friend
  
  It's Fall of Civilizations. The Aztec episode is actually only 4h 15mins, alas
  
  http://historyonfirepodcast.com/episodes/tag/Aztec
  You will not be disappointed.

Sex

I make espresso.

Self hosting, I guess it makes me an IT person as a hobby?
- Self-hosting*
  
  Selfhosting*

Photography.
I've been doing it for a long time and I'm still somewhat mediocre. It could theoretically make me money, but for me the excuse for not doing it boils down to "but it would require me to deal with people", given that most sought-after and commercially viable things to shoot are weddings, graduations and so on. In the end I keep it as something I (mostly) enjoy and occasionally do as favours to friends and family. I mostly shoot live music in order to support the local scene; I also do extreme sports and a bit of wildlife & landscapes.

I do almost the same thing as a(n unpaid) hobby that I do as my (paid) job. I'm a software developer who writes open-source software on the side.
I've also seen a few of my other hobbies grow into serious industries with real employees. The (hobby) drone industry and the 3D printing industry are quite large and growing (I assume).

I make pretty good beer and pretty shit furniture.

Linux Sysadmin here.
I have a couple open source apps/scripts that have tens of stars and ones of forks. I'm also getting into micro soldering to fix electronics. Mostly for myself but I'll hardmod or fix friends equipment for cost of parts. I've been known to buy a broken console, fix it, mod it, then sell it for some extra cash to buy more soldering equipment.
- That reminds me of the box of half-broken Game Boys from back when I got really into chiptune ... I kinda get backpain from soldering, though, any tips on that? Other than "go see a doctor", of course.
- Nice! What are your projects?

I write screenplays for fun.
I've written a bunch of short films and one day maybe one will get produced.
I'm also kind working on a historical drama feature film.
I really enjoy the creative process and don't truly care if I ever sell one it get one produced.

I fix all the tech at work because our IT department is dog trash and not fixing something when I know how feels like bees in my brain. Does that count as a hobby? :/
I also sometimes cook food in a more elaborate way than necessary which I've heard some people get paid for
- I considered this until I learned how much more IT is paid than me, without needing the education and certifications that I need.
  Funny, I can't seem to remember which port my mouse plugs into on my work computer now.
  
  this is a good point
  but also. bees in my brain
  hmmmmm

wrenching on my subaru :p during covid i pulled the engine. it was my first time ever pulling an engine out of a passenger car. i also pulled subframes and completely redid the suspension.
it keeps breaking, i keep fixing. symbiosis 🤝

A professional is someone who fell into the trap of turning their hobby into a source of income

I find distressed audio equipment and bring them back to life.
Here is a photo of some of the pieces I've worked on:
Top Shelf:
Adcom GP-555 It's actually dead. I cannot get the left channel to work at all. Resoldered the entire signal path, replaced the opamps, cleaned the controls, bypassed the controls.. Just cannot find where the issue is...
McIntosh MC7108: On/off circuit issues. This one I didn't really fix, just bypassed the affected circuit, because I don't care about turning it on and off via a switch. I use it every day.
Second Shelf:
Carver TFM-15cb: Needed new lights in the meters and the input level pots cleaned. That is all the one pictured needed. I have another one that required the same things, but also had to recap it. The one in the photo will need new capacitors before too long. Great sounding amps, but not very well built.
Bottom Shelf:
Soundcraftsman PRO-PA2X200: This is actually an amp my wife has owned for over 30 years. The power supply caps went out and needed to be replaced.
Here is a photo of said capacitors:

Maintaining and modifying cars and motorcycles.

Apparently I study timekeeping so much that I can program a clock on a graphing calculator without using any timer function.
It takes a fixed amount of time to alter a pixel on the screen, and when carefully crafted, the pixel clock itself serves as a timer.
I'm actually currently testing such a clock demo on my Casio right now.
- are there significant differences in pixel response as battery voltage goes down?
  
  Very good question!
  At this moment I don't know for sure.
  I've only been running it on consistent 5V USB power until yesterday.
  I am keeping the voltage level question in mind though...
  
  Update: To answer your question, yes apparently the calculator is indeed sensitive to variables such as battery voltage and even possibly/likely the temperature.
  I made a couple tweaks to the display layout, but left the core minute pixel timer algorithm alone. Tonight's test shows it's already off by a minute after only 25 minutes of running.
  Oh well, it's still a fun experiment, even though I was already aware I might be playing with digital fire with this silly project. 🤷‍♂️
  
  Welp, one of my 4 batteries died today (no worries on the memory on this model). I found a spare battery, but between that and switching back and forth to USB power, it does seem the calculator's speed might be lightly affected by voltage levels and even possibly by temperature.
  Hey, ain't nothing perfect...
- Timekeeping?
  
  Yes, as in the studies of everything between keeping up with time zone rules, knowing when the next lunar eclipse is (in the USA that's coming up shortly early morning March 14), and even learning and understanding how long different CPU instructions take.

Gaming.

Astronomy. I have a big ass reflector that I use for struggling to find globular clusters, oggling the fuck out of Jupiter and the Orion nebula, and very slowly working my way through the Messier list*. I considered going to school for it, for a hot second, but I kinda really don't want to end up the fucked up publish-or-die academia world making less money than I do now but with PhD debt.
*I don't use a GOTO system. No judgement for people who do, I've even considered a GOTO mod for when I do outreach, but I think there's some magic in slewing on to target by hand.

Gardening or more specifically raising fruit trees. Right now I got about 50 citrus trees growing from trifoliate orange seeds. Once they're ready I am going to graft lemons and satsumas onto them. I'm not planning to sell the trees, rather I'll gift them to friends and family.
I also propagate houseplants and gift them to friends, family and colleagues. Since they're so easy to propagate it's almost no effort.
- This is so wholesome, planting seeds figuratively and literally. Cheers!
- I also propagate houseplants and gift them to friends, family and colleagues. Since they’re so easy to propagate it’s almost no effort.
  Neat gift idea! I do have this hardy as fuck spiderplant that keeps multiplying instead of dying like most of my other plants ...

Doing stuff with CSS
- That is so cool. I suck at CSS.
- Me too

Mechanic. I have the tools and know how to fix my own car so long as we're not talking about an engine rebuild, (and even that I could do and have done in the past, but it's a pain in the ass usually and I don't wanna). I enjoy the tinkering and troubleshooting. If it were a more desirable and high paying gig, I could see myself doing it for work. I also am IT support for my boomer mom.

I brew alcohol and grow mushrooms(gourmet and non-gourmet)
- Man I wish home distilling wasn't illegal as fuck where I live ...
  
  You can't even brew beer? No distillation needed there

Influencer (I shitpost non-stop)

According to my ex, I'm pretty good at defending the horrible actions of others in a conversation
- You have a future in politics!

I have a machine shop that I use for making things out of metal that are normally not made of metal (like a yarn winder).

I am developing software as a hobby that is fairly specialized in nature. That is only because I could not get a job doing the same thing. Fuck corporate monopolies.

Ice hockey goalie. I’m no good at it, but it’s so much fun.

I enjoy learning vfx through houdini, id be doing it still if it wasnt so annoying to get on linux (im not paying for it, that 260$ a year cost is for me ppl making money and id do it if I was)
Blender is hella fun, like the ultimate sandbox game, cities skylines with no constraints (except much harder) I think with more and more addons it'll be the perfect sandbox creative city builder. Like procedural roads, cities, procedural terrain, buildings, etc. When the laxk of freedom in those games dissapoint you just make animations, the end goal in some of these games like planet coaster is to have something cool to look at and modify freely, the economy means nothing, might as well make it in blender.

Apparently there are people who receive monetary compensation for drawing comics. Some apparently can even do that as their main job. That's what I heard at least, they seem to be rare.

Not exactly the same but Truck driving Simulation on PC.

I have a bunch of hobbies but the two that I'm currently concentrating on are building guitars and working on motorcycles.
There are plenty of people who build or customize guitars for a living. I have sold exactly one that I built from scratch and that was probably 15 years ago.
I'm resurrecting a barn find motorcycle that I'll sell (or I'll sell one of mine to keep this, I haven't decided), but I'm not going to make any money on it because it's not sought after. I'm doing it for love. I'll break even.
- Oh man I would definitely watch a tv series on custom built motorcycles and guitars. I can already feel my moustache growing. Jokes aside, I love this kind of thing, have a garage full of creations, the grown man's playground.

I got really into cocktails a few years ago (or "mixed drinks", if you want to be more technically correct). No way I'd be able to keep up at a real bar, even if I probably know more cocktails than many of the bartenders I've personally interacted with (TBF I haven't been to a bar since I really got into cocktails, and before I got into it I just went wherever it was cheap). Fixing drinks is at best half of the job anyway, and I'm rubbish at the people stuff.
- What's the distinction between cocktails and mixed drinks?
  
  "Cocktail" is more specific. Originally, it was identical with what's now called an Old Fashioned, i.e. spirit, sugar, bitters and water/ice. Later the term started including other alcoholic drinks like sours, martini etc.; I've seen people claim in discussions that's it's down to the amount of ingredients (e.g. a Rum & Coke is not a cocktail, but rum, cola and lime (Cuba Libre) might be) or a specific care exercized in preparation, but I think it's ultimately arbitrary.
  Anyway, one of my favourite drinks is the Twice Up (whisky and water mixed 1:1, works great with many other spirits). Hard to call this a cocktail, considering adding water to whisky is just a completely normal way of drinking whisky in Scotland. The Scots just pour the water freehand instead of measuring an exact amount.
  
  One was mixed with a cock, and the other was mixed with a tail, obviously.. /s

I do nature photography

I bake fancy sourdough, grow vegetables, do landscaping (but not mowing) make great cocktails for people, ferment foods and drinks. Occasionally draw things for decorations.
On the other hand, we pay someone to mow, and also to clean the house every other week.
- I tried my hand at sourdough breads, but failed miserably. How long did it take you to become decent at it?
  
  The second time I made a starter it "took". Just regular unbleached all purpose flour and water. From there it was smooth sailing, it's a lot easier than yeasted bread for me. Main things that help:
  Always refresh the starter at least twice before making bread with it (so if you want to bake Saturday, refresh Friday morning then make the big starter on Friday night with some of that refreshed starter.)
  Refrigerate the dough after it's shaped. Untill it's cold or even overnight. This does two things. Makes it possible to do the scoring, and cold dough into a hot closed cast iron pot will create steam that helps it rise.
  Which leads to - bake it in a closed hot heavy pot. Commercial ovens can do things home ovens can't. I do all sorts of baking with the starter but for "the sourdough" as the kids call it, the one that comes out like a $12 Artisan Loaf, baking it enclosed by the hot pan is the trick. I tip the cold dough out onto parchment, score it then use the parchment to carefully move it into the hot pot.
  There is a sourdough community on Lemmy, they are a nice group and I'm sure would have more tips but those are mine.

I play golf, some days I wouldn't even call it a hobby more like penance and a walk in the trees and sticks

I try playing the guitar and taking photos.

My current favorite outside of gaming is selfhosting or homelabbing. Maybe not to a high degree but I manage four local servers and one offsite, with four websites. It’s pretty fun but makes me super stress when it fails. One of those websites is a work related database but it’s also very fun to manage.
Another small hobby I have is managing my own small library. Using LOC codes I learned from the library. I inherited a massive collection from retiring profs.