Northbound: settlement costs cut by 75% for container logistics
A hybrid optimistic + ZK rollup that cut settlement costs 75% for global container logistics.
Challenge
Northbound’s logistics platform tracks containers and calculates demurrage & detention fees at a frequency Ethereum mainnet simply can’t price. We designed and implemented a hybrid Layer 2: optimistic execution for throughput, with Circom-based zero-knowledge circuits providing private, verifiable state transitions where commercial confidentiality matters.
Approach
A custom off-chain batcher aggregates high-frequency tracking events before settlement, and secure L1↔L2 bridging with storage adaptors let Northbound’s existing contract logic run unmodified, with no refactor of a live system. The results were measurable: roughly 75% lower on-chain gas costs and 15× higher throughput, with data integrity still verifiable on Ethereum.
Outcome
Northbound now settles high-frequency tracking events at roughly 75% lower gas cost and 15 times the throughput, while data integrity stays verifiable on Ethereum.
Because storage adaptors let the existing contract logic run unmodified, the live system was never refactored or put at risk during the move.
Key results
- Hybrid optimistic + ZK rollup architecture
- Circom circuits for private, verifiable state transitions
- Storage adaptors: existing contracts ran unmodified
- ~75% lower gas costs, 15× throughput gain
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