The recent #Istanbul hard fork in December broke some important smart contracts deployed on #Ethereum mainnet.

Recommendations:
🚪When possible, consider using pull vs push design patterns for payments.

📬Be careful when using transfer() and send(), as these send a fixed amount of gas.

⛽️Perform gas analysis to understand boundary conditions and assumptions

Learn about what happened and how to prevent your contracts from breaking in this Quantstamp Labs post from Sr. Research Engineer Kacper Bak.

quantstamp.com/blog/breaking-bad-contracts-ethereum-gas-updates