Rain bridges Web3 payments with traditional card-issuing rails, enabling users to spend stablecoins through conventional payment networks.
57Blocks built Rain’s blockchain foundation, delivering smart contracts for settlement and liquidity, cross-chain interoperability, and a resilient backend architecture to support high-volume transactions across Solana, Stellar, and EVM environments.
What 57Blocks Delivered
Smart Contract Development: Led contract migration from EVM to Solana and Stellar, ensuring parity in logic and security across ecosystems.
Signature Authorization: Implemented on-chain signature verification systems - EIP-712-style authorization on Solana and multi-signature management on Stellar - validating privileged operations before execution.
Multi-Chain System Abstraction: Refactored the backend to decouple EVM-specific components, enabling modular integration of Solana and Stellar.
Asynchronous Transaction Throughput: Transitioned from sequential to concurrent task handling, supporting simultaneous multi-network transactions.
Idempotency & Concurrency Control: Added safeguards against duplicate submissions and race conditions during concurrent operations.
Resource & Fault Management: Introduced granular rate limiting, RPC fallback, automated recovery, and fault-tolerant event handling.
Tech Stack: Solidity, Rust, Anchor, Hardhat, Solana-Bankrun, PostgreSQL, Google Cloud, Prisma, ethers.js, @solana/web3.js.
Business Impact
Unified multi-chain settlement layer supporting Solana, Stellar, and EVM networks.
Achieved high-throughput, fault-tolerant transaction processing under production-scale load.
Enabled secure off-chain authorization and verified on-chain execution for card payment operations.
Strengthened backend resilience and resource efficiency for stablecoin-to-card payment flow.
Current Status
Rain continues to scale its Web3 payment infrastructure with 57Blocks supporting ongoing smart contract upgrades and multi-chain backend optimization.
