The easiest hack for speeding things up in SR5 is replacing mark-gaining mechanics with a net success mechanic. Net successes required for marks are spent, reducing the margin of success for the action. Let the highest number of marks achieved be persistent.
Example: Decker wants to reboot a device they currently have no marks on. This requires 3 marks, so they'll need to spend 3 net successes to get the marks. Their first attempt, they get 2 net successes, which isn't enough to reboot the device, but is enough to get 2 marks. Their next action, they again get 2 net successes, which is enough to get the 3rd mark and have 1 net success left over to accomplish the task.
Another big time-saver is passive matrix perception. Hackers get (Matrix Perception Pool)/4 as a passive check to find any hidden device in the area. No action required, it's just second nature by the time you've earned the right to call yourself a decker or technomancer. If they want to actively search, then they make rolls and spend the action.
Along those same lines, make Matrix Perception a simple action, just like the Observe in Detail action.