It has the potential to. But it might not ruin it completely.

Here are a few things that you need to think about

Industry move

Is your role similar to the role you've worked in previously?

Industry moves might show instability in your employment and income.

Pay structure

If your pay structure changes, like a move from salary to commission, you might be able to make more money, but underwriting looks at commission as less-stable than salary.

Going from salary to hourly is risky in the sense as well.

But going to a salary income is usually the safest. Salary is guaranteed money, and the move will be a lot more smooth.

If you're moving from an employee to a contractor/self employed set up, then this will likely derail your application.

Timing

If your new job can't provide proof that you're guaranteed to start within 90 days, underwriting won't take the new income.

Proving that you're guaranteed to start within 90 days means you need a non-contingent job offer. Contingencies are usually things like drug test and background checks.

Are you changing jobs the day before you close?

If you haven't let your lender know about your job change, here's what could happen:

The day before closing, they call the employer they have on file, on your mortgage application.

"Hello?"

"hi, is __ there?"

"Nope, they quit a few weeks ago"

"Okay bye"

In this situation, you're going to experience delays.

You won't be able to close the next day. The underwriter needs to know where you're working and reverify everything.

in the end

I'd avoid changing jobs if possible. If not, let your lender know as early as you can.