Well Thought-Out Tickets
Having really well thought-out tickets is a powerful lever in the speed of an engineering organization.
Developers can efficiently move forward in implementing features, rather than spending time tracking down information.
They don't spend cycles second-guessing what information they should probably know, and what knowledge is just missing.
This is also excellent for deadlines, because there is little to no loss of time spent on gathering information; all the engineer's time is instead spent on implementing - and with fewer mistakes in requirements.
The engineer is also less likely to task-switch, which is another significant speed boost: the authoritative source of information is the ticket, not random other sources (email, slack, Google Meet).
There is one incredible process that makes this possible: refinement. The exact process of refinement can vary, though, based on team maturity and dynamics.