If you get no responses, things are bad, maybe "start again" via a a bootcamp.
If you get responses but no interviews, try to get some feedback on why not and work on whatever the problems are.
If you get interviews but no offers, remember each interview makes you better at interviews and it's only a matter of time. Keep applying for jobs and working on any weak points which are revealed.
I like this approach. Troubleshoot what part of the job offer journey you are blocked it. In addition to the advice of 'Find Out', which can be in the form of the OP making a post and doing the above advice, one one area I see other Engineers who are out of the traditional Engineer path often neglect is reaching out within their network.
OP mentioned previous employment and having an undergraduate degree. Is OP still socializing with anyone they met in those environment. Is so talk about this goal to get back into the tech industry and ask for advice and execute. Show your network that you are trying so they can give you feedback.
I don't use any networking sites such as LinkedIn etc. but I've kept in touch with a couple of people from each of the places where I've worked. The biggest challenge with getting them to recommend me is that most of them have moved to a different country (mainly Canada and Germany). I'm not really keen on moving to another country, hence my apprenhension at having to apply cold.
Reconsider it, the network effects are undeniable. And if your former coworkers are international, believe it or not your network is even better (in the sense of blind opportunities coming your way). Don't discount LinkedIn just having a basic profile, albeit scarce, will be good enough. The value is reconnecting and gaining information of value to your goals (opportunities, recommendations, and getting a job in this case)
> I don't use any networking sites such as LinkedIn etc
Reconsider that. You can try to add everyone you remember from previous companies or school, and you'll be more available to recruiters. "Luck surface area."
Apply for a bunch of jobs. Let's say 30.
If you get no responses, things are bad, maybe "start again" via a a bootcamp.
If you get responses but no interviews, try to get some feedback on why not and work on whatever the problems are.
If you get interviews but no offers, remember each interview makes you better at interviews and it's only a matter of time. Keep applying for jobs and working on any weak points which are revealed.
Good luck!