A practical, intermediate guide to Chainlink VRF covering the security model, VRF v2 subscriptions, unbiased randomness patterns, local mocking/testing, and gas/cost optimizations for production-ready smart contracts.
Learn what a subgraph is and how The Graph Protocol lets you index Ethereum data with GraphQL. This step‑by‑step Hardhat + GraphQL guide shows schema, manifest, mappings, local setup, and best practices for fast, reliable Web3 data access.