Software Crypto Web3

This covers the full stack of blockchain development, from Solidity and Foundry on EVM chains to Anchor on Solana, CosmWasm on Cosmos, and TON contracts. It defaults to security-first patterns like checks-effects-interactions, explicit threat models for custody and signing, and comprehensive testing with fuzzing and invariant checks. The decision tree is helpful for picking between Foundry's advanced testing versus Hardhat's TypeScript ecosystem, or when to reach for L2s versus alternative chains. Notably includes backend integration patterns for .NET and event-driven architectures, not just contract work. The custody and key management section treats signing infrastructure as a first-class security concern, which is the right bias for production systems.