darren.jensen
I am a Security Researcher & Blockchain | LLM Engineer with 5+ years of dedicated Solidity auditing and 20+ years in software engineering across DeFi, Web3, and FinTech. Across Quantstamp and Oak Security I've delivered 60+ audits, acting as lead auditor on roughly half of my Quantstamp engagements. I hold an MSc in Computer Science from The University of Manchester alongside a Blockchain Developer Nanodegree and an AI / Machine Learning Nanodegree from Udacity.
On the AI side, I'm building an agentic DeFi yield platform which is a multi-agent system where a Portfolio AI Agent reasons over a user's on-chain positions and a Researcher AI Agent continuously embeds DeFi news and exploit reports into a vector index for semantic retrieval.
I have also held senior leadership roles including CTO at a FinTech startup in SE Asia. I'm currently open to both smart contract security engagements and AI Engineering roles where deep blockchain and security context is a valuable enhancement for building agents, retrieval systems, and LLM-powered tooling for DeFi, security, and on-chain intelligence.
REVIEWS FROM CLIENTS
Smart contract developer, backend engineer and technical architect for a DeFi lending and stablecoin protocol, spanning smart contract...
Smart contract developer, backend engineer and technical architect for a DeFi lending and stablecoin protocol, spanning smart contract engineering, security review, infrastructure, and technical project management. I've worked on multiple concurrent contract/audit engagements alongside my Liquid Loans role.
- Reviewed smart contract, backend and frontend code, and coordinated an external audit of the Liquid Loans monorepo smart contracts and oracle system with Halborn.
- Built an LLM-based test-generation system that automatically produces and runs Foundry and Hardhat test suites (unit, fuzz, and invariant) across the protocol's codebases.
- Applied LLM and agent-based tooling to assist internal security reviews - triaging code diffs and surfacing candidate issues ahead of the external Halborn audit.
- Led the core protocol development based on a Liquity V1 fork to then extend and deploy across multiple EVM chains via Hardhat, with Tenderly fork based QA.
- Deployed a Gnosis Safe fork including full support for multisig wallets, transaction builders, transaction indexing and and Safe Apps/plugins.
- Deployed a Tellor fork oracle with staking, reporting, and on-chain dispute resolution (auto-disputer bot), fronted by a modular oracle caller that fetches data via several off-chain and on-chain TWAP price feed.
- Designed the LOAN token and USDL stablecoin economics (issuance schedules, stability-pool and LP reward emissions) and Merkle-proof airdrop and claim contracts.
- Designed a multi-reporter oracle infrastructure on a Kubernetes cluster on AWS, with RPC failover across multiple providers.
- Developed a Dockerized Python arbitrage bot to hold USDL on its US-dollar peg on Aerodrome (Base), and deployed a Uniswap V3 managed strategy with Gamma Strategies and Merkl tokenized rewards.
- Built data indexing with The Graph, later migrating to SubQuery Network and serving data via GraphQL APIs.
During my time at Quantstamp, I completed over 50 audits across Solidity and Rust-based protocols, acting as lead auditor on approxima...
During my time at Quantstamp, I completed over 50 audits across Solidity and Rust-based protocols, acting as lead auditor on approximately half of all engagements. The protocols spanned a broad range of DeFi verticals including Oracles, Perpetuals, RWA, Bridges, Vaults, and Wallets. Notable clients include API3, Blockdaemon, PancakeSwap, RFX Exchange, SoDex, OnRe, Exceed Finance, Camp, Hipo Finance, and Crouton Finance, among others.
As a Smart Contract Security Researcher at Oak Security, I focused on auditing and enhancing the security of smart contracts. My role ...
As a Smart Contract Security Researcher at Oak Security, I focused on auditing and enhancing the security of smart contracts. My role involved collaborating with innovative protocols like Mars V2 and Size Lending, ensuring robust security measures were in place. I utilized my expertise in Solidity, Yul, and Rust (CosmWasm) to identify vulnerabilities and improve overall contract integrity.