Uber's board will seek an experienced boss, perhaps a woman.
He or she will need experience running a multinational.
Whether the board should hire someone with a background in transport (perhaps from an airline or logistics firm) or a candidate from the technology industry is unclear.
Some have suggested that Sheryl Sandberg, who serves as number two at Facebook, would be a good choice, but she may not be willing to jump.
Investors in Uber have accepted that Mr Kalanick will stay on the company's board (along with his co-founder and another early executive, he controls the majority of super-voting shares) so he is likely to have a strong influence on the firm.
He will need to exercise restraint.
Twitter, an internet company that is struggling to attract more users, found it hard to settle on a clear strategy in part because several co-founders who once ran it continued to serve on the board and second-guessed the boss.
Mr Kalanick's departure should be enough to placate some alienated customers.
Regulators may treat Uber more kindly, too.
Abroad, its scandals have barely registered.
In the first quarter of this year it notched up record revenues, of $3.4bn.
Its losses, of around $700m, are still high but diminishing.
The next chief executive will need to decide whether to chase growth and endure continued steep losses, or cut back on international expansion in order to make more money.
After watching Mr Kalanick push the pedal to the metal, Uber's investors may hope that a more conservative era—in terms of finances as well as culture—is about to begin.