Just like any software, smart contracts—code written into a blockchain that executes the terms of an agreement or contract from outside the chain—are susceptible to attacks, bugs, and coding errors. In this course, Michael Fawole, a blockchain developer and coach, shows you how to avoid serious problems with smart contracts—like financial losses and theft of assets—by employing ethical hacking. Michael shows you complexities of the most predominant attack in Web3—the reentrancy attack—and demonstrates how to prevent and guard against it as an ethical hacker. He shows you how to write vulnerability-free smart contracts, re-enter both simple and complex smart contracts, manipulate the arithmetical flow of contracts, and use ethical hacking techniques to test contract security—and prevent attacks from happening in the first place.