C++ Developer (Sq5)

CGI•Merrimack, NH

1d•Onsite

About The Position

CGI is seeking a highly skilled C++ Developer to design, build, and optimize high-performance backend services in a Linux environment. This role focuses on developing resilient, event-driven systems that handle real-time data and complex network interactions. You will work on long-running services and contribute to architecture decisions, performance tuning, and production stability. This position is ideal for engineers who thrive in low-level systems programming, asynchronous design, and debugging complex multithreaded environments. You will collaborate with cross-functional teams to deliver scalable and reliable backend platforms. This position is located at the client site in Merrimack, NH or Westlake, TX.

Requirements

Strong experience with modern C++ (C++17+) in Linux environments, particularly building long-running backend services
Proven expertise in multithreading including synchronization, race condition avoidance, and debugging deadlocks or teardown failures
Hands-on experience with network programming using TCP/IP sockets, including handling partial reads/writes and connection edge cases
Production experience implementing TLS/SSL secure communication and diagnosing related operational issues
Strong experience with asynchronous programming using Boost.Asio and familiarity with Boost.Beast for WebSocket communication
Experience with event-driven server architectures such as libevent or epoll-based frameworks
Demonstrated ability to debug production issues using observability signals such as logs, counters, and latency metrics
Deep understanding of memory management, object lifetime, and ownership models in asynchronous C++ systems
Familiarity with Linux service development including pthreads, signals, file descriptors, and linking strategies

Nice To Haves

Experience building low-latency or market-data style systems with subscription state, fanout, deduplication, and cache-aware response paths.
Boost stack experience beyond basics: Boost.Thread, Boost. Test, Boost.Filesystem, Boost.Log, BoostAsio, Boost.Beast.
Experience with observability in C++ services, including Prometheus-style metrics, latency percentiles, service health endpoints, and operational stats.
Experience with custom queues and work dispatch patterns in multithread application architecture.
Experience with creating scenario based tests using Cucumber framework.

Responsibilities

Design and develop high-performance backend daemons using modern C++ (C++17 or newer) on Linux
Build and maintain multithreaded systems including thread lifecycle management, synchronization, and safe shutdown handling
Implement robust networked services using TCP/IP sockets with full connection lifecycle management
Develop and maintain secure communication layers using TLS/SSL, including certificate handling and troubleshooting handshake issues
Build asynchronous I/O systems leveraging Boost.Asio and WebSocket clients using Boost.Beast
Architect and enhance event-driven systems using frameworks such as libevent or epoll-based reactors
Troubleshoot complex production issues using logs, metrics, and timing data without relying solely on debugger reproduction
Ensure safe object lifecycle management in asynchronous code using shared_ptr, callbacks, and queued execution models
Contribute to system performance improvements, scalability, and reliability in production environments