i've tried to run a side project alongside a full-time job three times. the first two ended in me abandoning it around month 4 because i was just exhausted all the time. this time i've been going for 11 months and still have some energy left. here's what's actually different.
the thing i stopped doing: evenings.
after a full day of work, my brain is not capable of making good decisions or writing clean code. i spent a year fighting this before accepting it. now i work on the project early mornings, 6-7:30am, before the job starts. two hours of real focus beats four hours of tired fumbling every time.
the thing i started doing: weekly scope cuts.
every sunday i look at what i planned and cut 30% of it. not because i'm lazy. because full-time job surprises will eat that 30% every single week without fail, and if i didn't cut it in advance i'd feel like a failure.
what i track: time actually shipped vs time opened laptop and dicked around monthly users or revenue (tiny numbers are fine, zero is a warning sign) my own energy levels, honestly: 1-5 scale, once a week
if energy goes below 3 for two consecutive weeks, i take one full week off the project. not a "light week." fully off. this has saved it twice.
the burnout pattern i watch for: caring more about the project than the job but not being able to switch. you're mentally at the startup all day but physically expected to be present at work. that's exhausting in a specific way.
what i'm not going to tell you: how many hours per week you should work on it. that's completely individual. i know people doing great work in 4 hours a week and people who burn out at 15. find your number and then underestimate it by 20%.
some of the best side project advice i got was: "build for a slightly longer timeline than you think and it'll stop feeling like you're always behind." year one, that felt like giving up. now it feels like survival.