Ponder
Ponder is an open-source backend framework for robust, performant, and maintainable crypto apps.

Web3's Backend - Envio - Web3’s Backend for Real-Time Blockchain Data
The fastest, most flexible way to get on-chain data. Envio is a modern multi-chain EVM blockchain indexer for querying real-time and historical data.

Squid SDK: Write Indexers for Production dApps and Analytics
Squid SDK is a modular toolkit for high-performance indexing. Get data from SQD Network and focus on your custom logic.