🗃️ GraphQL Indexer: The Graph Protocol

Blockchain nodes are terrible databases. Want to find all NFT transfers for a wallet? You need to scan millions of blocks, parse every transaction, filter events, and aggregate results. A simple query takes minutes and hammers your RPC endpoint. Etherscan, Uniswap, OpenSea—they don't query nodes directly. They use indexers: systems that watch the blockchain, extract data, organize it in a real database, and serve it via GraphQL. The Graph is the decentralized indexing protocol that powers most dApps.

// Pseudocode - actual complexity much worse
for (block = latestBlock; block > latestBlock - 216000; block--) {
  logs = eth_getLogs(block, uniswapV3Pool)
  for (log in logs) {
    if (log.topics[1] === wallet) {
      swaps.push(parseSwap(log))
    }
  }
}