How I saved $250K to go full time on my startup

Yes, what you're thinking in your head is correct - you can't really build a big business while having a full time job.

You can't do sales calls while at work
You can't openly promote your startup
Your job takes up most of your time leaving you only a few hours on the weekend and evenings

You can make some progress, but you're not gonna be able to raise money, get employees if you don't jump ship.

But Sukh I'm not gonna have an income. How will I survive? I got bills.

Yep it's tough. The key is to save enough money for your runway so that when you do quit, you won't have to worry about bills for at least a year, because I can tell you from experience that forcing yourself to make money ASAP is the fastest way to go into depression.

My runway number was $250K.

To do this, practically, there's only 2 numbers you can control:

How much you make
How much you spend

That's it. All your effort should be optimizing these two. You would be surprised how malleable these numbers are if you're flexible enough.

Here's how I saved $250K over 4 years to go full-time on my startup:

In 2019, I quit my full time job in Canada. I saw the same job in the US was paying 2x. Took the job and left the country. Immediately I could make the same money twice as fast.
Then in 2020, I moved to a low cost of living area. No paying $3K USD for a place with $20 lunches every afternoon. Bought a rice cooker. My monthly cost dropped.
At the end of 2021, I learned that you can get 3x more money if you work as a contractor vs. an employee and you're not subject to "40 hours" - as in if you can do the work in 10 hours vs. 40, the client loves that.
At the end of 2022, I started stacking contract jobs - doing 3 jobs at the same time. All async, remote and paid on delivery. Hella stressful but my annual salary went from $150K/year to $450K/year.
Eventually, I moved back to Canada but kept working for US companies. My living cost dropped even more.

By continuing to do this over and over, I hit my number at the end of Nov 2022 and I quit.

This period was the most stressful part of my life, but it needed to be done because there is no other way. There is no other way to chase the big dream.

If you decide to do something similar, here are a couple of lessons learned:

When you quit your FT, it's gonna be literally to sleep. You might get nightmares. They are temporary. Do the math on a piece of paper to convince yourself that you won't end up on the street tomorrow.
You have to find your own contract work. That means going to events, networking to find people that will pay you for the work. If you're a Dev, go to SF. There's plenty of work.
You might have to live out of a suitcase. The goal is to make enough money & dip. It's not to have the perfect apartment with matching cutlery. You see an opportunity, you make the move the next day.
Once you get good at making money, you might lose sight of the bigger goal: building a business. Don’t. Make sure that you actually quit. It’s pretty easy to continue to chase the cheques.
As a contractor, there is no job safety; you can be let go at the drop of a hat. That’s why the hourly rate is higher.

There’s a reason why 99% of people can’t do this. You can, now that you know the playbook.