Master the development, deployment, and security of smart contracts. From basics to advanced patterns and security best practices.
Smart contracts are self-executing programs stored on blockchain that automatically enforce agreements when predefined conditions are met.
A smart contract is immutable code deployed on a blockchain network. It contains business logic that executes deterministically when triggered by transactions. Once deployed, it cannot be modified (in most cases).
• Autonomous - executes automatically
• Immutable - code cannot be changed
• Transparent - code visible to all
• Deterministic - same input always produces same output
Smart contracts eliminate intermediaries, reduce costs, and enable new types of applications:
DeFi protocols, NFT marketplaces, DAOs, insurance products, supply chain verification, and more.
The primary language for Ethereum and EVM-compatible blockchains. Statically typed, contract-oriented, and feature-rich.
Building DeFi protocols, NFTs, DAOs, or any application on Ethereum, Polygon, BSC, or other EVM networks.
High-performance language used for Solana smart contracts. Offers memory safety and excellent performance.
When targeting Solana blockchain for high-speed, parallel transaction processing applications.
Used for enterprise blockchain smart contracts (chaincode) in Hyperledger Fabric networks.
Building enterprise-grade permissioned blockchain applications with compliance requirements.
Modern language designed for asset-centric programs with strong safety guarantees.
Developing on next-generation blockchains with emphasis on safety and performance.
Define requirements, architecture, and security considerations before writing code.
Write code using appropriate language. Follow best practices and design patterns.
Unit tests, integration tests, and edge case analysis. Use frameworks like Hardhat, Truffle, or Foundry.
Security review by internal team or professional auditors to identify vulnerabilities.
Deploy to testnet first, verify functionality, then deploy to mainnet.
Continuous monitoring for unusual activity, gas optimization, and performance metrics.
Validate all inputs and state before execution. Prevent reentrancy and overflow attacks through careful control flow.
Be aware of gas constraints. Avoid unbounded loops and expensive operations that could cause out-of-gas errors.
Implement proper access control mechanisms. Use role-based security and verify caller identity before sensitive operations.
Follow the CEI pattern: check conditions, update state, then interact with external contracts to prevent reentrancy.
Avoid relying on block.timestamp for critical logic. Miners have limited ability to influence it.
Document complex logic, assumptions, and potential risks. Include NatSpec comments for all public functions.
Reentrancy: Avoid external calls before updating state. Use state locks or checks-effects-interactions pattern.
Integer Overflow/Underflow: Use Solidity 0.8+ which checks for overflows, or SafeMath libraries.
Unauthorized Access: Always check msg.sender and implement role-based access control.
Front Running: Be aware that transactions are visible in mempool. Consider commit-reveal schemes if needed.
Main contract creates multiple instances of secondary contracts. Used in DeFi for creating pools or vaults.
Separate logic from data storage to enable upgradeable contracts. Common in protocol upgrades.
Fetch external data through oracle services. Critical for DeFi price feeds and external data integration.
Delay critical operations to allow users to react to changes. Enhances protocol security.
Require multiple signatories for sensitive operations. Standard for governance and fund management.
JavaScript testing framework with excellent developer experience and debugging tools.
Comprehensive development environment with integrated testing and deployment tools.
Rust-based testing framework offering blazing-fast test execution and advanced features.
Always test on testnets like Sepolia, Mumbai, or Fantom Testnet before mainnet deployment. This allows validation of functionality and gas costs without risking real funds.