One thing frustrating for me is when folk leave $BigCo, with it's methods (ie: estimate time to complete, sprint planning) and try to apply those same methods at a very early company.

Estimates don't work there at all - everything is new.

So, flip it. Use known values to prioritize work. That is: client demand and (potential) revenue. Then allocate known time/budget to the necessary project, see how far you get, iterate. Team can move faster. Looks chaotic.

At some (uncomfortable) point however, need to rotate into the "standard" process.