What’s the difference between the three orgs? Is the pay range for a SWE the same for all three?
Initial pay may be sort of similar, but pay scaling varies based on team. Closer you are to PnL generation/strategy, the more you'll make. This goes for Citadel and CitSec. Example - someone on Citadel GQS will generally have higher comp scaling than someone on PTE. Same deal on CitSec between its various teams.
What's PTE?
Post trade eng. back/middle office folks.
For swe there is no difference unless you are on a hft algos team (<1%)