[nRike]

> a new engineer, we'll call them Jerry, joined the startup I work at in a critical position.

No matter if he's the CEO, he should not be an asshole with their team.

> recently incredibly high demands and time constraints were imposed, and combined with failure for the company to meet revenue goals, have created a very stressful place to work.

So stress comes from not being able to make money. If you are just doing what your boss says, Jerry should not make it personal.

> My boss already knows how Jerry acts and hasn't done anything.

He's responsible of solve this issues, if he's doing nothing, you should leave ASAP.

Please, drop me a line at my personal email (look at my profile), I'd love to help you find a new job.