From my experience, the best way to get a pay increase is to code software for things closer to the trading system. Write code that makes a trading app faster and increases PnL, you'll make more money via bonuses. If you're writing back office code doing data loading, trade reconciliation or other "housekeeping" stuff, you'll not see the same comp.
Because of this, getting a SWE role that is assigned to a trading team is highly desired.