Senior Platform Infrastructure Engineer

About the role

Citadel Securities is seeking an exceptional Senior Platform Infrastructure Engineer to join the Platform Engineering team in New York. The team builds and maintains the foundational platform that orchestrates application execution at scale—including deployment, configuration, and reliability—for high‑frequency trading systems operating globally. This infrastructure is leveraged daily by Site Reliability Engineers (SREs) to ensure seamless operation of the firm’s trading platforms. The engineer will own design and development for core infrastructure components, impacting systems critical for cutting‑edge trading strategies enterprise‑wide.

Responsibilities

• Design, develop, and maintain critical infrastructure software, including components such as a process scheduler, configuration and deployment management system, and process‑state observability systems.
• Collaborate with SREs and production teams worldwide to continuously evolve deployment, configuration, and management tools for trading applications.
• Troubleshoot, diagnose, and resolve complex issues across distributed trading systems to ensure optimal performance and stability.
• Author and maintain comprehensive unit and integration tests to ensure high‑quality, reliable code.
• Contribute to and improve SDLC processes by leveraging industry‑standard tools (e.g., Jira, Git, Jenkins, Bazel) and adapt to evolving technology stacks.
• Document solutions and processes to enable firm‑wide adoption and ensure knowledge transfer across teams.

Qualifications

• Minimum 5 years of commercial experience with advanced C++ and Python programming, including production‑level development.
• Strong proficiency in Linux systems as a daily user, with experience building, deploying, configuring, and troubleshooting.
• Hands‑on experience with distributed systems in production environments.
• Experience with SDLC and tooling such as Jira, Git, Bazel, Jenkins, or equivalent alternatives.
• Ability to write maintainable unit and integration tests.

Preferred skills

• Experience with job scheduling and orchestration tools (e.g., Slurm, Airflow) at a developer level.
• Deep familiarity with Linux internals and tooling (systemd, cgroups, FUSE, etc.).
• Knowledge of security protocols relevant to infrastructure (TLS, Kerberos, Active Directory, etc.).
• Understanding of networking fundamentals (HTTP, DNS, multicast, TCP/UDP, etc.).
• Experience with cloud infrastructure management and infrastructure‑as‑code (Terraform).

Locations

Miami, New York City (opportunities may be available in any location where the business is based for suitable candidates).

About Citadel Securities

Citadel Securities is a next‑generation capital markets firm and a leading global market maker. It provides institutional and retail investors with the liquidity needed to trade a broad array of equity and fixed‑income products in any market condition. The firm’s brightest minds in finance, science, and technology use powerful, advanced analytics to solve the market’s most critical challenges, turning big ideas into real‑world outcomes. For more information, visit CitadelSecurities.com.