As everywhere else, the closer you are to the profit centres, the more you get paid: e.g. exchange connectivity specialist at an HFT shop, devops maintaining the plumbing and infra for ML systems, data wrangling specialist etc. Also, some funds are notorious for having made weird decisions regarding their main programming language (e.g. ocaml or q/kdb), so being a language specialist can also prove lucrative.
You can also look to join a trading team inside a fund - the ceiing is much higher on what you can be paid, but it's a lot riskier too. Generally, working on the infra side of a highly sophisticated algo fund is less risky.
Yes, this. I would go further and say that if you're "IT" in a finance firm you're a second class citizen. You want to do engineering in a trading role: designing prop trading strategies, managing portfolios and pnl.
There are very few financial firms that are tech companies at the core. The landscape today is certainly better than it was ten or twenty years ago. Today, the firms who have a standing chance to compete in the arena have automated everything.
I'm making sweeping generalizations, so obviously YMMV.
It's really a matter of culture; virtually all places will have a clear delineation between Investment and Technology, with various perks given to Investment people: better visibility into what is going on, access to higher management, general power to influence which projects need work etc. Also, Investment people tend to hang out together.
EDIT: Just realised you were maybe not commenting on the 'second class citizen' bit. I'll leave my comment here anyway.
From a income maximisation PoV, that's true. However, OP was looking to not increase his risk, so taking PnL risk might not be what he wants.
Wait, what? Have you ever been an SRE at FAANG? I am currently an SRE at Google and I am absolutely well respected by everybody and compensated in the exact same band of my peers SWE at my level (L5 at ~400k TC), and the career growth opportunities are the exact same. In fact, I used to be an SWE and switched to SRE due to the challenges being more vibrant and better aligned to my interests.
All my friends who do SRE work at Facebook have a similar experience.
The vibe is more of a tech firm with people working quietly in front of their copmputer.
The grass is always greener.