I'll take a crack at some of these.
I'm a professional software developer. I've done freelance for years, mostly accessibility/access tech related, though I've had a couple general web development gigs. I don't know if your definition of full-time is 40 hours/week, but I think that's kind of a ridiculous metric as long as you do the work that needs doing without burning yourself out. I do about 15/week now, though that's mainly due to being fairly strict on how much I'm willing to compromise my rates, and even then I'm probably a bit too generous. But even with a compelling rate, I'd probably max out at 30-35 hours/week, saving at least one weekday for creative or personal projects.
Are you working for a company? Yes and no. Essentially freelance, but I just took the step of creating an LLC, electing S corp tax status, setting up payroll, and putting myself on it. Huge pain in the ass, but it's given me a different perspective when I'm negotiating rates with clients. My overhead is much more front-and-center this way, and rates that seemed exorbitant don't seem nearly as high now that I'm on the hook for quarterly tax payments, employer taxes, etc. The numbers are probably fairly close to what they were as a sole prop, but with them due regularly, I don't feel nearly as bad about charging more.
What area of development does your work focus on? Pretty much full-stack, though I kick visual web design tasks onto other folks. My current gig has me dabbling in Kubernetes, a Hasura GraphQL API, a Vue frontend, a Kotlin backend, and all the glue/supporting tech needed to keep the whole herd of cats moving in roughly the same direction. That's another reason I try sticking to 15 or so hours per week, because after a few hours of that much context-switching, my brain wants to drip out of my ears. Today I just debugged an Auth0 issue where it turned out their developer documentation was almost certainly wrong. I'll be smoking a huge bowl after today's workout, that's for sure.
Is their in-house software accessible? Since I run this company of 1, I can categorically state that software to run a business is not at all accessible. I use Quickbooks Online to manage my finances, and basically just paid an accountant to set things up for me. Fortunately, most of it can be automated, and their form e-filing support saves me from having to submit paper, so accessibility-wise it's probably barely a net gain. I haven't found an accessible contract-signing service that works from the initiator side since docracy.com sold out to Eversign. If I'm ever fortunate enough to hire a team, or if my client ever becomes a company that can hire me personally, I know Slack isn't accessible as a groupchat solution. GitLab issues work well enough for tracking organizational work, but if we ever need project management beyond something like that, I'm not sure what we'll use. The whole thing is kind of exhausting, and contributes further to the brainmelt.
What made you choose to work for that company? For myself, the fact that I'm not chasing interviews, that I have some freedom in what I do. That I'm not stuck working an 8-hour day is also a plus, as is the fact that I don't have to commute, or to fight with whatever inaccessible collaboration tools some remote company uses. I keep hoping to pick audio game development back up, but haven't found the sweet spot between the demands of $dayjob and the creativity something like game development requires. Still, though, it's distinctly more possible working for myself than it'd be were I stuck in a cube.
What did you major in college? English, with computer science and business minors. But college was two decades ago, so it doesn't really matter quite as much anymore.