I think you are wise to worry. Last year I was laid off from a company whose technology I helped build for years. I was promoted up to the position of "CTO"... with no team below me. It was a very small company working on email archiving and encryption that still runs today. As the system admin and solo developer I was spread thin, working on a system that now processes anywhere from 80 to 120 (150?) million emails a month. In the last several months I sent out my resume to at least 40 different companies, but the only offer I received was through someone my previous boss knows. It isn't a CTO level position.

To be clear I was let go because the company ended up having financial difficulties. It is a strange story to tell and sometimes I wonder if people think I am weaving it as I go. I'm not. It did leave me severely burnt out and I find the question "what was your biggest accomplishment?" to be a frustrating one during interviews because I did so much for that previous company that I almost don't remember any of the subtle details. I thought that the numbers would speak for themselves but nobody seems to care. I find it bizarre.

The other thing that might be fascinating is that the technical portion of interviews seem to be where things stall out for me. I would never claim to be an incredible programmer, but my previous companies system was not a trivial piece of software. I am probably going to give my one and only job offer a try and see how that goes. shrugs

Finally when I say build I mean to say that there was a PKI api + c library for interfacing that layer when I started. The website, the inbound/outbound email processing, the ES portion of the service etc were all built by me. So the parts that brought the actual customers were built by me.