Gas Optimization on Polygon PoS: Reducing Settlement Costs by 94%

When we launched on Polygon, naive implementation cost us $0.017 per settlement. At 50,000 daily transactions, we were burning $850/day in gas. Sustainable at our margins, but leaving significant optimization on the table.

The Batching Architecture

Individual on-chain settlements are wasteful. Each transaction carries base costs for signature verification, state access, and event emission. Batching amortizes these costs across many settlements.

// Before: Individual settlements
for (settlement of settlements) {
  await contract.settle(settlement); // $0.017 each
}

// After: Batched settlements
const merkleRoot = computeMerkleRoot(settlements);
await contract.settleBatch(merkleRoot, proofs); // $0.00089 per settlement

We batch settlements every 15 minutes or 1,000 payments, whichever comes first. A single on-chain transaction commits a Merkle root; individual merchants can prove inclusion and claim funds independently.

Calldata Compression

Ethereum's calldata costs 16 gas per non-zero byte. We compress settlement data using domain-specific encoding, reducing average calldata size from 847 bytes to 124 bytes per settlement.

• Address compression using registry indexes (20 bytes → 3 bytes)
• Amount encoding with decimal scaling (32 bytes → 6 bytes)
• Timestamp delta encoding (8 bytes → 2 bytes)