Senior Platform Infrastructure Engineer

Job Description
Role Overview
Citadel Securities is seeking an exceptional Senior Platform Infrastructure Engineer to join one of our Platform Engineering teams in Miami or New York. Our team is responsible for building and maintaining the foundational platform that orchestrates application execution at scale-including deployment, configuration, and reliability-for our high frequency trading systems operating across the globe. This critical infrastructure is leveraged daily by Site Reliability Engineers (SREs) to ensure the seamless operation of the firm's trading platforms.
As a key technical member, you'll take ownership of design and development for core infrastructure components. This role is a unique opportunity to make a direct and significant impact on systems critical for the successful execution of cutting-edge trading strategies enterprise-wide.
We are building software infrastructure to reliably run a constantly changing trading system that contains many thousands of interdependent applications in many thousands of hosts in dozens of locations all around the globe.
We are looking for candidates with a passion for robust distributed systems, solid software engineering fundamentals, and demonstrable experience deploying and managing production-scale trading infrastructure.
Opportunities may be available from time to time in any location in which the business is based for suitable candidates. If you are interested in a career with Citadel Securities, please share your details and we will contact you if there is a vacancy available.
Responsibilities

• Design, develop, and maintain critical infrastructure software (notably components like process scheduler, configuration and deployment managements system and process state observability systems)
• Collaborate with SREs and production teams worldwide to continuously evolve the 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), with flexibility to adapt to evolving technology stacks
• Document solutions and processes to enable firmwide adoption and ensure knowledge transfer across teams

Qualifications

• Minimum 5 years of commercial experience with each of the following:
• Advanced C++ and Python programming, including production-level development
• Writing maintainable unit and integration tests
• Linux systems as a daily user (strong proficiency in building, deploying, configuring, and troubleshooting)
• Hands-on experience with distributed systems in production environments
• SDLC and tooling (such as Jira, Git, Bazel, Jenkins, or equivalent alternatives)

Preferred

• Expertise or experience with any of the following will be regarded as a strong plus:
• Job scheduling and orchestration tools (e.g., Slurm, Airflow), especially at a developer level
• Deep familiarity with Linux internals and tooling (systemd, cgroups, FUSE, etc.)
• Security protocols relevant to infrastructure (TLS, Kerberos, Active Directory, etc.)
• Networking fundamentals (HTTP, DNS, multicast, TCP/UDP, etc.)
• Cloud infrastructure management, infrastructure-as-code (Terraform)

In accordance with applicable law, the base salary range for this role is $175,000 to $350,000.
In addition, the employee who fills this role will be eligible to participate in a discretionary incentive compensation program, as well as a wide array of benefit programs, such as medical and life insurance, retirement and tax-free savings plans, and access to other healthcare programs.
About Citadel Securities
Citadel Securities is the next-generation capital markets firm and a leading global market maker. We provide institutional and retail investors with the liquidity they need to trade a broad array of equity and fixed income products in any market condition. The 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.