Decentralised Finance Platform
Cross-chain DeFi protocol enabling seamless swaps across Ethereum, Polygon, and Avalanche with multi-sig smart contract security and $100M+ processed.
Project Overview
A well-funded DeFi startup needed to build a cross-chain liquidity protocol from scratch. The goal was to allow institutional and retail traders to swap assets between Ethereum, Polygon, and Avalanche with minimal slippage, transparent fees, and auditable on-chain history.
The founding team had domain expertise but no in-house engineering capacity. We joined as the full technical team — architecture, smart contracts, backend, and frontend.
The Challenge
Cross-chain bridges are the most exploited category in Web3. High-profile hacks (Ronin, Wormhole, Nomad) had collectively lost over $1.5B. Our primary mandate was building a bridge that wouldn't be the next headline.
Secondary challenges:
- Liquidity fragmentation — Without deep liquidity on both sides, swaps would have unacceptable slippage, especially for large institutional orders
- Gas optimisation — Ethereum mainnet gas costs would kill the UX for smaller trades
- Regulatory ambiguity — We needed architecture that could adapt as OFAC and MiCA regulations evolved
Architecture
Smart Contract Layer: We designed a hub-and-spoke bridge architecture with a multi-signature validator set (5-of-7 threshold). Contracts were written in Solidity, with Rust used for performance-critical off-chain relayers.
Security Posture:
- All contracts passed three independent audits (Trail of Bits, Certora, Halborn)
- Formal verification on core bridge logic using Certora's Prover
- Emergency pause mechanism controlled by a time-locked multisig
Liquidity Management: An automated market-making layer managed liquidity pools on each chain, rebalancing based on observed swap demand.
Backend Relayer: A distributed Go service listened for events across all chains and orchestrated the cross-chain message passing, with retry logic and dead-letter queuing for reliability.
Results
- $100M+ total volume in first 3 months post-launch
- 0 security incidents across 18 months of operation
- 99.99% uptime on the relayer network
- Successfully passed regulatory review under MiCA (EU) framework