Spark.Fi - Smart - deCircle

Spark is building one of the most important pieces of infrastructure in DeFi: a scalable on-chain capital allocation engine designed to move billions in liquidity efficiently across lending markets, yield strategies, and liquidity venues.

As the ecosystem matures, the challenge is no longer simply creating protocols, but designing systems that can intelligently deploy capital, generate sustainable yield, and manage liquidity at scale across increasingly fragmented markets. Spark sits directly at the center of that evolution.

We are looking for a Senior Smart Contract Engineer to help architect and build the core primitives behind Spark’s vault infrastructure, AMM integrations, and yield-generating systems. This is a deeply technical role focused on designing secure, capital-efficient smart contract systems that interact with lending protocols, liquidity pools, and automated strategy frameworks across the DeFi ecosystem.

The ideal candidate understands that modern DeFi infrastructure is ultimately a liquidity coordination problem. You should be comfortable thinking about how capital moves between protocols, how yield is generated and distributed, how vault systems abstract complexity for users, and how liquidity mechanisms behave under real market conditions.

You will work on:

ERC-4626 vault architectures

Yield allocation and rebalancing systems

AMM and liquidity pool integrations

Automated capital deployment frameworks

Treasury and liquidity management infrastructure

Reward distribution and fee accounting systems

Strategy execution and risk-aware routing mechanisms

A large part of the role involves building systems that abstract complexity while remaining transparent, composable, and secure. You will contribute to infrastructure responsible for managing large-scale on-chain liquidity and enabling efficient access to yield across the broader DeFi landscape.

This is not a role focused purely on writing Solidity in isolation. We are looking for someone who understands the economic behavior behind the code:

how liquidity behaves under volatility,

how yield incentives shape user behavior,

how AMMs impact capital efficiency,

how vault architectures can optimize deployment strategies,

and how protocol design decisions influence systemic risk.

You’ll collaborate closely with protocol engineers, treasury and risk contributors, and product stakeholders to design systems that can scale responsibly while remaining highly composable within the broader Ethereum ecosystem.