A more typical number among my SaaS buddies is about 18 months of sustained effort until you hit $10k in MRR, which typically is enough (after expenses) to keep a solo founder in the field indefinitely.
The fastest I've ever seen it done is about ~6 weeks for SaaS. Even shorter for infoproducts, although depending on the dynamics of the business that might be "launch one, get relatively flush with money, buy yourself enough time to launch a second one" until you figure out some not-too-obvious things about how to sell them repeatedly.
A consultant, naturally, can hit day job equivalent levels of revenue virtually immediately after hanging out their shingle (if they've got a client lined up). A fairly common pattern is "Inform day job of intention to quit; immediately go back to working for day job as 1099 during transitionary period; start building pipeline while delivering for Client #1."
Best of luck at this new role :)
So far so good, but it confirms me that Europe is slower for firing up a project.
There is not a big entrepreneurship culture in general (at least in Spain & Southern France) so starting a startup, learning through others experience, next steps etc.. It's harder.
Also the social pressure is a big reason why entrepreneurship is hard. While in USA, failing and starting over is seen as something natural, in the various Spanish and French communities I have lived is seen as a disaster. Even more in some places is seen as an intent of showing everyone that you are smarter than them so you create your own product/service in stead of working in making better the existing ones. I think it's a cultural thing.
To clarify: it was a project outside of my 9-5, which made it feel side-projecty. It was also something that was paid on a contract basis which made it 'somehat official'.
I negotiated almost 2.5 months to get this contract, which also made it feel real.
I may not be answering your question, but I'm sharing this so that others know that this is a possibility and also because I wanted to. :)
Another 2 years or so of temping, miscellaneous web work, and anything else to pay the bills.
It has now been 2 years where the website is truly my full-time work and I'm looking to hire my first employee in the next few months. Pretty excited about that!
That was a little more than 6 years ago and it has continued to be our full-time project. However we did add versions on most other platforms and a cloud sync service, and I'm not sure that we would've continued to generate good revenue without those additions.
I ended up not using my savings as the business started to grow 1k/month after I quit my job.
I eventually switched getting paid for my side project because, it was open source, better management, and I got paid better. And I love doing it.
For me, the worst thing is siting at the office, doing job for someone else and not being able to care about my project and customers. Doing it full time is a huge relief.
It's only just getting close to something that I can share with people, so I won't be working on it full time in the near future (if ever).
Adjusting it would definitely helps clarify if that's not what you meant. Perhaps, "How successful was your side project before you went full time?", or "How much MRR / traction... ?"