In this job market? Stay where you are but start looking.

They’re going down whether you stay or not. Take care of yourself, nobody else will.

In essence, you and others see the impending crash - others do not? Analyse your role and, what made it 'sink', and determine if the 'holes' are terminal or if they can be patched and the ship saved - this assumes you know chapter/verse of the cause(s). This inside data might be of value to any potential 'White Knight' saviour to see if there is a save possible, and if not what can be built from the scrap metal - at whatever stage. This might allow you to craft a better role with your detailed knowledge - even an enduring role at a relaunch or with the use made of the parts. Your conclusions might be of value to the captain who steered them onto the rocks - or he might want to hand you an anchor to help you swim. The best defence is your own network and help delay the plunge and see how these options fan out. As others say, provision your own lifeboat as well and keep it ready as long as the cook is still feeding the crew in the gally. You are not alone, various startups have failed over the years - small/large. Their histories are probably archived in HN and will offer insights/connections. Good Luck.!!

> ...they cannot afford to lose me...

Questions:

Do they know that?

How will they treat you for the 6-12 months? (Yes, "very well" sounds logical. But "bully him to do the work of all the departed engineers" is a sadly common human reaction.)

Work enough to not get fired but not so much you burn out, look for other jobs, build your savings further, be prepared to collect unemployment when they fold or you’re let go.