I Broke Production 3 Times: Smart Contract Deployment Mistakes You’re Making

I’ll never forget the feeling. Our newly deployed staking contract was live. Users were depositing funds. Then the messages started flooding in:

“Where’s my money?”
“I can’t withdraw!”
“The contract ate my ETH!”

I had broken production. Again. This was the third time I’d deployed a buggy contract to mainnet.

After losing sleep, user trust, and thousands in gas fees, I finally built a deployment process that actually works. Here are the mistakes I made — and how you can avoid them.

💥 Mistake #1: The “It Works on Testnet” Fallacy

What I did: Deployed to mainnet because “it worked on Goerli.”

What went wrong:

// Testnet worked fine
function claimRewards() external {
require(block.timestamp >= claimTime, "Too early");
// ... logic
}
// Mainnet disaster: users couldn't claim for 30 days
uint256 public claimTime = block.timestamp + 30 days;