L4s get paid a market-related base salary (estimate of £150k in post above is probably about right), plus celebratory RSU grant on promotion (vesting over 5 years), plus equity grant to top performers (again vesting). L3s and up get paid based on # of units, which in turn are based on leadership position, business growth, etc. At the top of L3, this would probably be mid to high £200k. Plus all of the extras mentioned above.