Tech companies often offer so called Bug Bounty to ethical hackers, in order to motivate them to find vulnerabilities and imperfection in the code of the apps they are developing.
Crypto companies are no different, they motivate coding pros with bounties to help them secure their exchanges, blockchains or wallets better.
A great example would be the $250.000 bounty offered by John Mc.Afee to anyone who can hack the Bitfi wallet that he is developing. More info here : https://bitfi.com/bounty