Ask HN: Interested in game engine programming, not gamedev

> how should I demonstrate skills?

Your list is correct. Any/all. Open source everything and if you make a game engine, make games in it.

> is engine programming less exploitative?

Depends on how you mean. Working in the games industry usually involves dealing with the same handful of warts regardless of where you go and what your title is. The exception is depending on your seniority/role/specialization, those warts may manifest differently. As a junior engine programmer, you're still going to have to deal with the same things any lower ranking games industry person is going to have to deal with.

With time though, engine programmer becomes one of those specs where the money is insane and the job security is better than usual.

If you are passionate about a particular game or engine, hack and mod it to oblivion! Devs love to hire someone who has already turned their code inside-out just to improve it (like the modder Rockstar just hired). And the infosec background should help with this.

Looking in from the outside, engine dev seems to be in a weird place. Lots of studios (Bioware, others at EA, CDPR, BGS, Paradox, just to name a few) are suffering from messy releases because in-house engine development was more than they could chew. And startups with really interesting engine ideas (like Dual Universe) largely burnt out.