Older, former programmer returning to work as Tier 2 Application Support?

Depends on the sector you are targeting. Startups and big tech is fairly toxic in their culture and ageism, sexism and other bigoted behaviour is way more acceptable there than in smaller companies. For instance, in my previous company (startup) there was an unspoken cut off at age 35 for anyone under senior level and I don't think we ever hired anyone over 40 who wasn't aquihired. My current company (game dev) is a much more diverse group and skews more towards older people with a good number of developers over 50, and the remaining people evenly distributed across all ages (with a slight deficit on the junior count). The startup culture was way more boy's club and always filtered for "cultural fit". The pay was great, but in hindsight having to mask everything wasn't healthy and not worth the money. In contrast, my current company is diverse, and explicitly accommodating and welcoming, with a large chunk of us on the neurodivergent and LGBTQ side. Pay is definitely lower - I'm sure I could get a 50% raise by going to a banking job, but going to work is finally not psychological terror anymore. You have experience, and gaps can be "massaged" to look better by "having worked on a startup idea that didn't pan out" or so. As long as you can talk about relevant experiences you should be fine. And additionally: there's a lot of legacy code out there that was written when you left the industry that still needs maintaining. Always remember that even the COBOL developers didn't run out of work even decades after the language fell out of fashion.