Job Description At Citadel Securities, our engineers work in small teams to turn the best ideas into high-performing and resilient technology. With short development cycles, work rapidly goes into production. As an engineer, you can create systems architectures, develop platforms and build web frameworks. You'll have access to state-of-the-art tools and apply innovative techniques including distributed computing, natural language processing, machine learning and more. As an intern, you'll get to challenge the impossible in technology through a summer program that will allow you to collaborate and connect with senior team members. In addition, you'll get the opportunity to network and socialize with peers throughout the internship. Your Objectives: - Create technological tools that bring trading strategies to life - Develop high-performance, large data research platforms - Work in small teams to build the future of finance Your Skills & Talents: - Bachelor's, master's or PhD in computer science, computer engineering or related fields - Exceptional programming and design skills - Strong analytical skills and familiarity with probability and statistics - Ability to communicate effectively in a collaborative, complex and highly technical team environment - Intellectual curiosity and passion for solving challenging problems using technology. 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. We collect and use personal data in accordance with our Privacy Policy. We retain data on prospective candidates and may consider suitability for alternative opportunities at Citadel Securities. For more information, see our Privacy Policy. About Citadel Securities Citadel Securities is a technology-driven, next-generation global market maker. We provide institutional and retail investors with world-class liquidity, competitive pricing and seamless front-to-back execution in a broad array of financial products. Our teams of engineers, traders and researchers harness leading-edge quantitative research and the accelerating power of compute, machine learning and AI to power our analytics and tackle the market's and our clients' most critical challenges. Together, we are forging the future of capital markets. For more information, visit citadelsecurities.com .

• Ship at least 3 PRs on your first day • Drive full-stack feature development from conception to deployment, owning key product initiatives end-to-end • Collaborate on the design and implementation of user-facing features that improve the experience • Build robust, performant web applications using modern frontend and backend technologies • Identify opportunities for optimization and enhancement in existing systems • Contribute to the architectural decisions that shape the product • Set the industry standard for the UX of agent products • Build AI/LLM integrations as a core part of the product, not a bolt-on—agent-facing UX, not just prompting

Role Description At DDN, you will work on infrastructure challenges that sit at the core of modern high-performance systems: - Building and optimizing FUSE-based file system technologies - Working across Linux kernel file systems and user-space infrastructure layers - Designing high-performance infrastructure for distributed storage environments - Improving how object storage systems behave under real production workloads - Working with RDMA networking principles and high-speed data movement - Solving performance bottlenecks across networking, storage, and I/O pathways - Developing systems-level infrastructure in C and C++ - Building platforms that support AI, HPC, and large-scale data-intensive workloads Your work will directly influence how large-scale infrastructure platforms perform in real-world production environments — not just in theory. Qualifications - Strong hands-on experience developing with FUSE and Linux file systems - Deep understanding of Linux kernel file system architecture - Strong programming skills in C and C++ - Strong understanding of POSIX file system principles - Experience with object storage systems and distributed infrastructure - Familiarity with RDMA networking principles and high-speed networking technologies - Experience working close to kernel-space and user-space I/O paths - Strong systems mindset with the ability to debug complex infrastructure and performance issues - Experience building or optimizing infrastructure platforms in production environments Requirements - You enjoy low-level systems and infrastructure engineering - You care deeply about performance, scale, and reliability - You like solving technical problems that most engineers avoid because they are too deep or performance-sensitive - You enjoy understanding how storage and networking behave under pressure - You prefer working close to the metal instead of purely abstracted application layers - You want to build infrastructure that directly powers mission-critical environments Benefits - This role is probably not for you if: - Your background is primarily application-layer or general backend development - You have limited experience with Linux internals, file systems, or infrastructure engineering - You prefer higher-level platform abstraction over systems-level development - You have not worked on performance-sensitive distributed systems - You want a coordination-heavy role rather than deep technical ownership

Role Description The .NET Developer will be responsible for creating and implementing custom web-based solutions utilizing C# .NET and Microsoft SQL Server. Key responsibilities include: - Experience with ASP.NET and Microsoft SQL Server. - Experience with MVC .NET Core API is a plus. - Willingness to assist and support daily ad-hoc requests. - Testing and deploying applications and systems. - Revising, updating, refactoring, and debugging code. - Developing documentation throughout the software development life cycle (SDLC). - Serving as an expert on applications and providing technical support for clients. - Providing advanced analysis and programming related to the design, development, and support of systems. - Consulting with stakeholders to define system requirements, problems, and proposals; providing leadership for detailed studies; obtaining agreement and approval for proposed updates/changes. - Conducting advanced systems studies that include feasibility, conceptual design, cost/benefit analysis, and development/implementation planning; preparing estimates of resource requirements in terms of time, cost, and equipment for systems design, as well as programming. Qualifications - At least three years of current professional experience in web development in the Microsoft stack. Requirements - Visa: USC / GC, EAD H4 EAD. Company Description