What are some hurdles you'll come across while hunting for a job after trying to build your own startups (unsuccessfully for 5+ years)?
I'm a software engineer. I'm a generalist who does many other things as well, but I guess that's the role I'd best fit into in an organization.
How do companies look at the long gap since your last actual job? Would they consider you a high risk individual who can leave at a moment's notice if they get another business idea? What could I do to put that concern to rest?
Maybe it's just my luck lately, but I'm finding it harder to find a job after having done my own startups for several years.
Working on a startup isn't a "gap", it's an experience, even if different from other jobs on your list. Working on your own startup can be a positive experience, depending on what kind of skills you applied and learned and what type of results you can show for it.
Your startup experience would be more appealing to other startups and would only be a concern for large organizations because they would worry about a "culture fit". Unless of course you have nothing to show for your years working on a startup and I don't mean financial success, but rather an ability to show your growth and what you were able to accomplish as a software engineer - designing solutions from scratch, etc.
I don't know where you are, but the market for engineers in big metro areas is excellent and there are a ton of startup companies that struggle getting experienced engineers to leave big/medium companies for them.
So it comes down to how you sell yourself and what you have to sell. Ask yourself, what have you learned from your experience and how could it be beneficial to your future employer? It's possible your skills are a little behind, especially when it comes to tools and some practices like deployment or unit testing. Do you know where you fit better - front-end, back-end, infrastructure, systems/ops? Ideally, you have an anchor skill/language (if you don't, build one) and know what you prefer to work on - not knowing what your strength are and saying you can work on anything is a bad signal to interviewers.
Consider interviews a learning experience - ask questions about how the company works, what is QA and deployment is like, what tools they use. Then lookup anything you are not familiar with when you get home. Have an opinion on things. Also, do research the company before the interview and compliment people on something they had done or ask specific questions about strategy, new product, etc. If you want people to invest in you, you need to invest your time first.
Lastly, you should get better as you go through interviews and learn about what hiring managers are looking for and maybe identify your weaknesses.
TLDR: Startup experience isn't a negative factor in interviews, if you know how to sell your experience and actually have something to sell.
First thing: don't label yourself a failure. Not everyone can put 5+ years like you have into something they believe in.
You're actually in a better position than people who have not tried and failed at their ventures. You've proven that you're a self starter.
I would highly recommend that you try a lesser known approach to job hunting for ex-founders: contact recruiting partners at VCs.
Many VCs help their portfolio companies by sending skilled candidates their way. Greylock is just one example of a VC that actively does this.
Have no shame in cold calling or emailing their recruiting partners with something like: "I'm an entrepreneur who has built x startups and interested in exploring opportunities with your portfolio companies. My main specialty is xyz". You'd be surprised how receptive they are to entrepreneurs seeking employment -- unlike entrepreneurs who cold email to try and raise money (which rarely get a response).
You know from your experience what does and doesn't work -- so you can help a startup avoid some potholes. That's worth a lot more in value than someone without that experience.