Jobs at Citadel Securities

Lead architecture and engineering of high-performance crypto market feed handlers and exchange connectivity. Build low-latency ingestion, normalization, sequencing, order book construction, and distribution systems; drive venue onboarding, data quality, reconciliation, recovery, and replay; improve latency, throughput, resiliency in a 24/7 production environment; partner with trading and research teams; mentor engineers and define operational KPIs.

The role involves building and supporting production-level trading systems in C++ for credit and rates products, collaborating with traders and quantitative researchers.

Build full-stack, low-latency trading and pricing tools for options traders. Collaborate with traders, researchers, and business stakeholders to design intuitive frontends and scalable backend services, prototype and productionize distributed systems, and expand trading capabilities globally while improving performance, stability, and usability.

As a PhD intern, you'll develop trading strategies, conduct statistical analysis, backtest models, and collaborate with experienced team members in quantitative research.

Build and optimize low-latency, high-performance C++ trading systems for crypto markets; partner with researchers and traders to productionize strategies; optimize latency, throughput, reliability; implement pricing, risk, and execution logic; analyze large-scale market and trade data; ensure resilience, testing, and scalability across global venues.

Conduct end-to-end ML research for options trading: design experiments, train large-scale models (LLMs/transformers), build scalable pipelines, validate and deploy models to production, and translate research into measurable P&L impact.

Software Engineers at Citadel develop, maintain, and support high-performance trading platforms, focusing on custom software solutions and system stability.

Design and develop software solutions, analyze complex problems, and provide support for trading activities in a dynamic environment.

Design, develop, and deploy software solutions for automated trading systems while collaborating with researchers on technology priorities.

Design and optimize electronic trading platforms, develop pricing and risk-management libraries, and collaborate with research teams on software solutions.

Design, build, test, and maintain scalable regulatory reporting applications and data pipelines. Translate regulatory requirements into technical solutions, investigate reporting exceptions, reconcile data, optimize processing frameworks, and support the full software development lifecycle with monitoring and automation.

As a Quantitative Researcher, you will develop trading strategies, implement mathematical models, analyze data, and contribute to high-level research in a trading environment.

11-week internship performing quantitative research to develop, backtest, and implement automated trading strategies. Translate mathematical models into code, analyze unconventional data sources, conduct statistical research (ML, time-series, NLP), and collaborate with senior researchers to refine trading signals and monetize models.

The intern will work on developing high-performance research platforms, create tools for trading strategies, and collaborate with teams to innovate financial technology.

Conduct original research applying machine learning, deep learning, and NLP to extract patterns from large and unstructured datasets; implement and back-test algorithms in high-quality code; document findings and collaborate with trading teams to deploy research-driven models.

Build high-performance, production-ready trading and research platforms in small teams. Design systems architectures, develop platforms and web frameworks, apply distributed computing, ML and NLP techniques, and collaborate on complex technical problems.

Design, build, and operate high-performance Kdb+/Q platforms for real-time and historical market data, partnering with traders and researchers to deliver scalable time-series analytics, streaming, and trading solutions while driving architecture, automation, and operational excellence.

The Senior Options Software Engineer will design, develop, and support a high-performance trading platform, collaborating with business leaders to create innovative software solutions and handle complex systems support for trading activities.

11-week internship supporting quantitative trading: develop market knowledge, apply statistical techniques to trading, iterate strategies, and use the firm's trading platform. Collaborate with traders, engineers, and researchers while building programming and quantitative skills.

As a Quantitative Research Analyst Intern, you will model markets, develop algorithms, and conduct statistical analysis to enhance trading strategies.