Current roles: Head of Quant Engineering at LayerV since January 2026; Senior Quant Developer in Systematic Options Trading at Capital Delta since April 2025.
Senior Quant and Backend Engineer with 20+ years building production software. I specialize in low-latency trading, options, exchange infrastructure and distributed systems using Rust, C++, Go and Python.
I lead exchange engineering across matching and limit order books, option chains, real-time risk, liquidation and institutional RFQ services, with SBE streams and REST/WebSocket APIs. My experience includes multi-venue execution, smart order routing, FIX connectivity, transaction cost analysis and Greeks-based risk controls. I work with Kubernetes, AWS, PostgreSQL, Redis and NATS/Kafka.
I created the open-source Rust projects OrderBook-rs, OptionStratLib and market-maker-rs for order books, options pricing, Greeks, simulation, market making, risk controls and backtesting.
Based in Madrid, Spain. Available immediately for fully remote roles or contracts with companies worldwide. I strongly prefer very small teams, ideally 1 to 10 people. Target: approximately USD 150,000/year or USD 100/hour for contracts.
Website: https://joaquinbejar.capitaldelta.co
GitHub: https://github.com/joaquinbejar
Telegram: https://telegram.me/joaquin_bejar
Education: BSc Finance at the London School of Economics and Political Science, January 2023 to present, in progress. MSc Artificial Intelligence at Universidad Internacional, October 2018 to September 2020. BSc Mathematics at The Open University, November 2013 to July 2017. BSc Computer Science at Universidad Pontificia de Salamanca, September 1996 to July 2000.
Experience: 4 years
Yearly salary: $150,000
Hourly rate: $100
Nationality: 🇪🇸 Spain
Residency: 🇪🇸 Spain
Experience
Senior Quantitative Software Engineer
Sphinx 2024 - 2025
08/2024 to 04/2025. Built market-making and liquidity-routing infrastructure for an onchain perpetuals exchange, including dynamic quoting, delta-neutral hedging across futures, CEXs and AMMs, and margin and inventory controls. Developed a Rust/Go/Python stack with Kubernetes, Redis, PostgreSQL and AWS, plus telemetry and oracle sanity checks.
Senior Software Developer
BlackBird.video 2022 - 2022
03/2022 to 11/2022. Moved complex applications to AWS microservices, ECS and Lambda. Built low-latency, high-throughput audio and video systems in C++, Rust, Python, Bash and Go, with CI/CD, Docker and Kubernetes.
Senior Quantitative Developer
Swissblock 2022 - 2024
11/2022 to 08/2024. Developed an algorithmic cryptocurrency trading platform, exchange connectivity, order management and execution. Built a Go smart order router across venues using FIX and REST/WebSocket APIs, adaptive rate limits, transaction cost analysis and routing comparisons. Worked with Go, Python, C++, Rust, Kubernetes, Kafka and NATS.
Quant Developer
Flow Traders 2019 - 2022
02/2019 to 03/2022. Designed and delivered smart order routing in modern C++ for multi-venue execution using FIX and native APIs. Built transaction cost analysis, routing comparisons, exchange connectivity and microsecond-level telemetry. Worked with C++, Python, REST, WebSocket, gRPC, FIX and SBE.
Senior Security Software Developer
EUIPO 2018 - 2022
09/2018 to 03/2022. Led development of security services and data pipelines protecting web portals. Built APIs for GeoIP and Layer 7 attack analysis using Python, C++, Bash, MongoDB, Redis and MariaDB, with AWS, Azure, Docker, Kubernetes, Terraform and GitLab CI/CD.
Senior Software Developer
Joint Research Center 2017 - 2018
07/2017 to 09/2018. Led development of an AI model to predict malaria outbreaks in countries with limited data. Worked with AWS, C++11, Python, Docker, GitLab, CI/CD and MySQL.
Software Developer, Taxes & Customs
European Commission 2016 - 2017
11/2016 to 07/2017. Developed data analysis and predictive modelling applications for fraud detection in financial data using AWS, C++11, Python, Pandas, Scikit-Learn, Docker, Git and Hadoop.
Senior Software Developer
Deutsche Bank 2015 - 2016
05/2015 to 11/2016. Built analytical tools and data pipelines for complex datasets using C++, Python, R, Pandas and NumPy, with Redis, RabbitMQ, Docker and Git.
Skills
aws
backend
c-plus-plus
defi
golang
kubernetes
postgres
python
redis
rust