What does the possible career progression look like for a tools programmer? Would experience in that field be useful to gain other programming jobs in the industry, like gameplay, engine or AI programming? Or is it considered experience that only qualifies you for further tools programming jobs?
What does the possible career progression look like for a tools programmer?
No one knows. Every career path is different.
Would experience in that field be useful to gain other programming jobs in the industry, like gameplay, engine or AI programming?
Now the question you did not ask:
I want to become an engine/gameplay/AI developer, should I start by applying on jobs for developing tools because that's the only thing I have the qualification for?
Like anything related to career, it could be possible. And you could also be stuck at what you do for various reasons. You could get a job doing X and always be assigned to the same job, on the same franchise, for ten years, even if you ask HR to move you somewhere else (because, you know, you're good at it, and you know the part of the software, and we need a monkey to do that boring job). You could also get a job doing X because you want to eventually do Y, but finally find out that X is so much fun and challenging that the desire to do Y is not there anymore, and keep on doing X, on the same franchise, for ten years, and love it (because, you know, there are still so many improvements to be done and you have the freedom to apply them). You could start doing X, ask to be moved elsewhere in the company, but get stuck there, and decide to move to another company to do Y.
Yes, any experience helps (even if you're not from a game dev background), as long as that's what you seek and there are opportunities (it's harder if you're in a small town with only one game dev studio). This will depend on you, the company where you work, etc...