Backend Engineer — Storage & DeFi

You will own services that interface directly with custody systems and on-chain protocols. Custody integration layer — communication with vaults, key ceremonies, withdrawal flows. DeFi integration — AAVE positions, DEX liquidity provisioning, staking flows, on-chain event listeners. Asset accounting that survives audit. Cross-chain settlement logic. Blockchain reorg handling that does not create reconciliation nightmare next morning.

Work sits at intersection of two unforgiving worlds. Custody side punishes any sloppiness with regulator letters and lost capital. DeFi side punishes any sloppiness with smart contract exploits and lost capital. Margin for error is roughly zero on both ends. People who like that intensity thrive here.

Who Fits

You have shipped code that talks to blockchains in production, not just on testnet. You understand difference between confirmed and finalized, and why it matters for accounting. You have read Solidity well enough to spot something off in protocol you are integrating with. You think about idempotency obsessively because chains do not retry the way HTTP does. Custody integration experience (Fireblocks, Copper, Anchorage, BitGo, Taurus, Sygnum, in-house systems) is asset.

Stack Signals

• Rust strongly preferred for on-chain and storage layer (Go acceptable for service work)
• Solid grasp of EVM internals, account abstraction, common DeFi primitives
• PostgreSQL + Diesel ORM comfort (we use Diesel intentionally — mistakes here are expensive)
• gRPC + Protobuf for internal services
• Kubernetes, Docker, AWS at production level
• Smart contract reading fluency (writing not required, but welcome)