DeFi development refers to designing and building decentralized finance protocols using blockchain. It includes creating smart contracts for lending, borrowing, swaps, liquidity pools, yield farming, staking, synthetic assets, insurance, and payment systems. Developers architect tokenomics, governance frameworks, and secure, composable modules. They integrate front-end UI, wallets, oracles, cross-chain bridges, and analytics. Security is paramount: audits, bug bounties, and formal verification are standard. DeFi development enables permissionless access to financial products, removing intermediaries, reducing costs, and fostering inclusion. It’s powered by networks like Ethereum, BSC, Solana, and Avalanche and underpins a rapidly growing decentralized financial ecosystem.