Top C# Jobs

Develop scalable C++ software that defines and enforces endpoint behavior across millions of managed Windows endpoints. Responsibilities include implementing features, improving platform performance, shipping production code, designing new systems, writing architecture documents, defining subsystem contracts, and collaborating with server, UI, product, and design teams. The role requires deep Windows systems and kernel-driver expertise, with preferred experience in WHQL, minifilter or WFP drivers, macOS Endpoint Security, and Linux kernel development.

Leads complex software optimization initiatives from design through implementation and validation. Builds cloud-native services, data pipelines, dashboards, automation, and AI-enabled forecasting solutions. Analyzes cloud costs, resource utilization, reliability, capacity, and engineering productivity while partnering with Engineering, Finance, Product, Data, Platform, and SRE teams. Ensures scalable and secure integrations, testing, observability, financial data quality, and measurable savings. Provides technical leadership and mentorship to junior engineers without direct people-management responsibilities.

Design, develop, optimize, deploy, and maintain high-performance market data and automated trading systems. Process raw market data feeds, implement CME and Cboe exchange protocols, and optimize concurrency, throughput, scalability, and ultra-low-latency performance. Collaborate with traders, quantitative researchers, analysts, and engineers while supporting critical applications, automated testing, peer reviews, and best practices. Coach junior engineers and take ownership of projects from design through maintenance.

Ten-week paid software engineering internship developing, testing, and deploying C++ solutions for a proprietary trading platform. Interns work with large datasets, network programming, multithreaded applications, AI coding tools, and cross-functional technologists and researchers. The role includes mentorship, complex problem-solving, collaboration, and opportunities for full-time employment after graduation.

Develops, tests, troubleshoots, and maintains secure, stable, and scalable software components in a Linux C/C++ environment. Responsibilities include system design, application development, technical problem-solving, SDLC execution, automation, CI/CD, resiliency, security, and responsible use of AI-assisted development tools. The engineer collaborates within an agile team and analyzes data to support reliable application development.

Develop modern C++ systems for systematic investing, including low-latency data processing, high-frequency trading execution, quantitative analytics libraries, and machine-learning inference tools. Collaborate with quantitative researchers to build scalable, reliable, and performant production platforms, design distributed data pipelines, evaluate system architectures, and maintain fail-safe live-market trading infrastructure.

Develop and test high-performance C++ applications for trading platforms. Collaborate with traders and senior engineers to translate requirements into efficient solutions, while monitoring, profiling, troubleshooting, and improving system reliability. Gain hands-on experience across the full trading-system development lifecycle in an on-site, highly collaborative environment.

Design, develop, and maintain high-performance C++ trading platform applications. Partner with traders and quantitative researchers to translate business needs into efficient technical solutions. Lead profiling, performance optimization, testing, code review, and release improvements while owning features from design through production support.

Build and optimize low-latency C++ systems for market data processing, exchange connectivity, and order execution. Analyze performance across application, memory, CPU, networking, and operating-system layers. Collaborate with traders, FPGA engineers, and infrastructure teams, while owning production systems through design, testing, deployment, and real-time support.

Design and develop scalable C++ software for endpoint state and control across Windows, macOS, and potentially Linux. Build reliable, multi-process systems that enforce endpoint behavior, manage local state, support IPC, and operate across millions of devices. Responsibilities include implementing features, improving platform performance, writing design documents, defining architecture and IPC contracts, and making technical decisions in an evolving, sparsely documented environment.

Build and scale low-latency ad-serving software handling billions of daily auctions. Responsibilities include developing data- and model-driven features, optimizing algorithms and architectures, reducing cloud costs, extending observability, supporting distributed infrastructure, participating in on-call rotations, and documenting systems and incident procedures.

Designs, develops, tests, deploys, and supports large-scale software for a video advertising platform. Owns feature lifecycles, writes technical specifications and efficient code, integrates software components, documents functionality, and develops quality assurance procedures. Collaborates with product, operations, and engineering teams, provides technical leadership, resolves production issues, researches relevant technologies, and mentors junior engineers. The role requires expertise in C/C++ or Golang, database design, network programming, distributed systems, and large-scale software development.

Develop and test systems-level C++ software that defines and enforces endpoint behavior. Initially, the engineer will own testing infrastructure and coverage for two active projects, then contribute to feature development. The role requires strong C++ fundamentals, automated testing experience, and interest in operating-system concepts such as processes, file systems, services, and APIs. Work includes learning unfamiliar systems, collaborating effectively, and supporting reliable endpoint security and management capabilities.

Build software, data pipelines, dashboards, and automation for cloud cost visibility, infrastructure efficiency, reliability, engineering productivity, and financial accountability. Analyze workloads and billing data, implement AI- and analytics-enabled forecasting and anomaly detection, develop cloud-native services, and support capacity planning, cost allocation, and optimization. Collaborate with Engineering, Finance, Data, Platform, SRE, Architecture, and Product teams while testing, troubleshooting, documenting, and communicating recommendations and business value.

Develop and maintain sports trading and tools applications and platforms using .NET, C#, and SQL Server. Build scalable, low-latency, highly available software handling high-volume real-time data. Support existing 24/7 trading systems, perform root-cause analysis, collaborate with product owners and testing teams, contribute to solution proposals and estimates, and mentor technical team members. The role will also expand into Golang, React, and Google Cloud Platform.

Design and build data-driven advertising software features, scale distributed applications and infrastructure, optimize algorithms and architectures, reduce cloud costs, and improve observability. Participate in on-call rotations and incident escalation, create technical documentation and playbooks, and collaborate with distributed teams across time zones. The role requires strong software architecture, performance optimization, data modeling, Linux, and compiled-language expertise.

Design and implement high-performance datapath features for load balancing, firewall rules, and Layer 7 protocols. Build scalable networking and security systems using C or C++, data structures, algorithms, and Unix/Linux optimization. Own architectural projects from conception through large-scale deployment while applying advanced knowledge of DNS, HTTP, TCP/IP, and SSL/TLS. Use AI tools to improve engineering workflows and problem-solving.

Design and implement high-performance datapath features for load balancing, firewall rules, and Layer 7 protocols. Build scalable networking and security applications using C or C++, advanced data structures and algorithms, and Unix or Linux systems. Own complex architectural projects from concept through deployment while applying expertise in DNS, HTTP, TCP/IP, and SSL/TLS to enhance global network infrastructure.

Develop and maintain C#/.NET applications, SQL databases, and manufacturing execution systems supporting automotive production. Monitor and maintain servers, virtual machines, workstations, and production equipment; troubleshoot incidents, debug code, and support system reliability, backups, clustering, and disaster recovery. Collaborate with production, infrastructure, security, and database teams, provide technical support and training, document incidents, and help maintain high availability of manufacturing IT systems.

Develop and maintain SpaceX’s core test infrastructure framework and applications for production testing, integration testing, simulations, and flight systems. Improve software reliability, performance, safety, and user experience while collaborating with flight software engineers. Responsibilities include software design, development, testing, deployment, monitoring, performance optimization, and solving complex engineering problems. The role is onsite and may require extended hours or weekends based on launch schedules.

Designs and builds scalable, resilient distributed systems and applications using .NET, C#, microservices, REST APIs, cloud platforms, containers, and DevOps practices. Responsibilities include architecture, coding, code reviews, reusable components, monitoring, continuous delivery, infrastructure as code, cross-functional collaboration, mentoring engineers, and improving engineering processes.

Develop C++ software for a medical and safety equipment technology project. Apply strong object-oriented programming skills, work with PostgreSQL and/or MongoDB, and contribute hands-on development expertise. Experience with Versant DB and embedded systems is beneficial. The role is local to the Boston area and requires at least seven years of C++ development experience.

Lead maintenance and expansion of a flagship Windows client-server accounting product. Design, implement, test, and document features; maintain large legacy C++ codebase while developing in C#/.NET. Collaborate with cross-functional teams, gather user requirements, optimize databases, ensure code quality, and apply finance domain knowledge to deliver reliable accounting software.

Support and enhance the Geneva portfolio management platform and related Windows applications. Integrate Geneva for inputs/outputs/reporting, develop new modules, test and deploy code, resolve production issues, and collaborate with business users to deliver requirements.

Develop and deploy secure payer interoperability solutions using C#/.NET, HL7 FHIR, ASC X12, MongoDB, and Azure. Build APIs, claims and prior authorization workflows, cloud-native data exchange pipelines, and CI/CD deployments. Manage Azure storage, messaging, secrets, and API governance while collaborating with technical and business stakeholders to deliver scalable healthcare integration services.