When I joined this at-the-time growing company, we were a group of 8 senior developers. After the m&a, we had layoffs, some IT was affected but morale was basically destroyed to the point where each and every developer left, one by one, until there is only me. They don't have the best documentation ever, and I am pretty much the only one that currently knows how everything runs and where everything is.
How delicate or strong is my position? What should I be on the lookout for?
It sounds like management is not incredibly concerned about maintaining the original company's knowledge or infrastructure. Either that, or they don't understand the requirements.
Also, why was morale destroyed? If developers were the stars of the show before, and then just a cog in the machine after, some don't like the lower status and look for greener pastures. Was it that simple, or were there more issues involved?
I would bring this to your manager as a "What if I were hit by a bus?" problem. Don't try to leverage your position. At worst, you'll confirm what you already suspect: That your original company's intellectual property wasn't a big concern of the M&A, and they're willing to let it fall by the wayside. However, you may be letting the sun shine on something they were unaware of, and may find yourself a department head.
Whatever you do, don't approach it from the idea of leveraging more money or authority out of them. Bring it to them as being honestly concerned for the company's well-being, and go from there. Someone who's genuinely concerned is someone they can trust with authority. Someone who's in it only for themselves is someone they need to figure out how to get rid of.
Getting "acquired" is always wierd.
The bottom line is: how are you getting along with the new owners? If you are meshing well with their people and becoming an active member of their organization, then treat it as a new job. If you are like a space alien or leper or something, look for a company where you will fit in better.
