Blockchain & Solidity: Lessons Every Web3 Dev Should Internalize The blockchain doesn’t forgive mistakes. Solidity doesn’t either. ⸻ 1️⃣ Assume Users Are Adversarial •Every input could be malicious. •Expect replay attacks and exploits. •Design contracts defensively. Solidity teaches you to never trust anyone, even yourself. ⸻ 2️⃣ Be Explicit About Permissions •Use OnlyOwner, ReentrancyGuard, SafeMath. •No shortcuts or hidden assumptions. Clear permissions prevent millions in lost funds. ⸻ 3️⃣ Limits Exist for a Reason •Caps, cooldowns, and fees prevent catastrophic errors. •A small mistake can cost tens of thousands. Never ignore constraints for “convenience.” ⸻ 4️⃣ Frontends Lie, Contracts Don’t •Frontend UIs are mutable. •Contracts are immutable. Always validate on-chain. Trust nothing off-chain. ⸻ 5️⃣ Expect On-Chain Assumptions to Break •Block timestamps, swap prices, flash loans: all can change unexpectedly. Design for uncertainty; anticipate adversarial timing. ⸻ 6️⃣ Reverts Are Costly •Failed transactions burn gas and reduce trust. •Always check, double-check, and revert early. Prevent lost funds and frustrated users. ⸻ 7️⃣ Past Audits Don’t Guarantee Safety •Code evolves. Attackers adapt. •Test constantly, even after audits. Security is continuous, not a one-time checkbox. ⸻ Takeaway Solidity isn’t beginner-friendly. It’s exploit-friendly. Your mindset, discipline, and understanding of incentives matter more than your syntax skills. ⸻ #Blockchain #Solidity #Web3 #SmartContracts #Ethereum #DeFi #Web3Dev #BuildInPublic