Principal Software Engineer, Cboe

• The ideal candidate has spent years building low-latency, high-volume distributed systems, has a deep understanding of RESTful, gRPC, and streaming transport protocols, and treats API design, versioning, and backward compatibility as first-class engineering concerns
• Bachelor’s degree in Computer Science, Software Engineering, or a related STEM field
• 10+ years of hands-on experience in professional back-end and distributed systems development
• Expert-level command of C#/.NET and ASP.NET Core for building high-throughput, production-critical services
• Demonstrated ownership of a platform-level or externally consumed API — design, versioning, documentation, and support of the consumers on it
• A track record of building low-latency, high-volume, highly available distributed systems
• Strong OOP skills, experience with design patterns, and a solid grounding in computer science fundamentals including data structures, algorithms, and concurrency
• Experience mentoring engineers and providing technical leadership across teams
• Experience dealing with customers through support and requirements analysis
• Advanced experience with C#/.NET and ASP.NET Core, including async/await, concurrency and threading models, and memory- and GC-aware performance work
• Microservices architecture, service decomposition, and event-driven design
• Proficiency in building RESTful APIs, gRPC services, WebSockets, and other real-time communication methods
• Expertise in throughput optimization techniques, serialization (MessagePack, Protobuf), and compression methods
• Experience with message brokers and streaming platforms such as Kafka, RabbitMQ, or Redis
• Strong understanding of data structures and algorithms, profiling, and performance optimization
• Strong SQL skills, sufficient to write and tune complex queries against production workloads
• API Platform & Integration:
• Contract-first API design using OpenAPI/Swagger and Protobuf IDL, with a deliberate approach to schema evolution and versioning
• Command of API gateway concerns: routing, throttling and rate limiting, quotas, idempotency, pagination, and a consistent error model
• Experience publishing and maintaining developer-facing API documentation and client SDKs
• Networking fundamentals — TCP/IP, TLS, HTTP/2, load balancing, and connection management for long-lived streaming sessions
• Testing & Quality:
• Expertise designing and implementing unit, integration, and contract test automation for services and APIs, using xUnit/NUnit and API/contract testing tooling
• Experience embedding automated tests into CI/CD pipelines as release gates
• Load, soak, and latency testing of services at realistic market-hour volumes
• Data & Persistence:
• Proficient in database technologies such as Postgres, SQL Server, and MySQL, and ORM frameworks like Entity Framework
• Schema design, indexing, query tuning, and zero-downtime migrations across transactional and time-series workloads
• Security:
• Expertise in implementing authentication and authorization using OpenID Connect, OAuth 2.0, and related security standards
• Secure API practices including input validation, secrets management, and least-privilege access
• Experience with security code scanning and remediating identified vulnerabilities
• Other Skills:
• Proficiency using AI coding assistants such as Claude for code generation, test creation, code review, and refactoring
• Familiarity with Agile/Scrum methodologies and DevOps practices (CI/CD pipelines, automated testing, etc.)
• Comfortable with Windows and Linux operating systems
• Excellent communication, problem-solving, and leadership skills
• Containerization (Docker/Kubernetes) and cloud platforms (Azure, AWS, or GCP)

Desirable

• Cboe’s Data Vantage division — the team behind the Silexx order and execution management platform — is looking for a Principal Software Engineer to lead the design and build-out of our back-end services and API infrastructure
• This is a hands-on principal role for a seasoned back-end engineer who is an expert in C#/
• NET and who thinks in terms of contracts, throughput, and reliability
• You will architect and implement the services, APIs, and real-time data pipelines that power Silexx’s trading, analytics, and risk-management workflows, and you will define how our own clients and our customers’ systems integrate with the platform
• You will be comfortable working with AI coding assistants such as Claude across the software development lifecycle to accelerate delivery and raise quality
• Lead the design, architecture, and implementation of Silexx’s back-end services in C#/.NET — spanning order and execution workflows, market data, analytics, and risk
• Own the API platform end to end: define REST, gRPC, and real-time streaming contracts, establish versioning and deprecation policy, and maintain backward compatibility for the internal teams and external clients that depend on them
• Build and scale real-time data distribution — market data fan-out, order and execution event streams, and low-latency messaging — against explicit latency and throughput targets
• Define the service topology: decompose large components into well-bounded microservices, set service boundaries, and establish standards for inter-service communication
• Implement secure server communications and authentication/authorization using RESTful and streaming protocols, OpenID Connect, and OAuth 2.0
• Drive observability, capacity planning, and performance profiling for systems that must remain available through market hours, and maintain a highly available production platform
• Partner with the front-end, WPF desktop (Silexx OEMS), and client-integration teams so that the APIs you design are practical for the clients that consume them; support customers through integration, requirements analysis, and troubleshooting
• Establish back-end engineering standards — automated unit, integration, and contract testing, CI/CD release gates, code review, and API documentation
• Provide architectural direction for continued growth into new asset classes, products, regions, and models; distill complex requirements into manageable features and tasks
• Mentor engineers across teams, help managers onboard and train new associates, and act as a key participant in the interview and assessment process
• Diagnose and resolve complex production problems spanning the service, data, and network layers