Cars are often huge money sinks. Also, people tend not to examine their housing situation for efficiencies (I have a number twenty-something friends in small towns who own houses with rental properties that cover nearly all their mortgages) - also, you can generally move closer to work and bike or take transit (assuming you're not a consultant and "work" is a fixed place); this goes back to cars being money sinks and commuting really being terrible. You can eat really well quite cheaply if you want to put in some time and make your own food (a bagged lunch over eating out at work could save you $1000 a year, and that's just one thing). Anyway, the Internet is full of useful tips to save money, but you can get a bunch done by just mapping out your monthly spending and looking for places to trim the fat. Maybe that won't cover the whole 10-15K you're looking for, but it's a good start.
1. Build something on the side that creates recurring revenue
2. Build something on the side that you can sell for $10-15k
3. Build multiple things that, when combined, sell for $10-15k
4. Negotiate a raise at your current job
5. Start doing freelance work
6. Get lucky in the stock market
7. Get lucky in a casino
8. Get lucky in a lottery
9. Inherit some money
This will be way easier than building a SaaS app. Trust me.
EDIT: No idea why this is getting downvoted. Any insight would be appreciated.
"Don't end the week with nothing" - Patio11 https://training.kalzumeus.com/newsletters/archive/do-not-en...
Start building something you can sell. It could be a book, an app, a SaaS. You might not (probability won't) get it to +$15k this year. That shouldn't stop you from beginning. If you make something thst people are willing to pay for, you should be able to EVENTUALLY get to +$15k (and more!)
It's close imposible to get money without making something useful. If you are programmer your treasure is coding, so if working for someone else as freelancer is for somebody not good idea, because it won't make enough money and you have already full-time job, probably only another way is making something on your own.
If you cannot change jobs now, why don't you add to your skill set over the next year with the view of using these enhanced skills when you can look for a new job?
2. Post your resume and ask for 15k more
3. If you're not in the SF Bay Area, move there but note your cost of living will probably go up by 20k so you need to ask for $35k more than you currently make.
4. If you're in the SF Bay Area, see if your company will let you work remotely, and move to a state that has no income tax.
5. Marry/Date up (lawyer, doctor, programmer, executive :-)