Top Senior C# Jobs in San Francisco Bay Area, CA

Develop cross-platform C++ and Qt software for network device discovery, monitoring, and data collection across Windows and Linux. Build high-performance, concurrent, asynchronous systems that communicate with thousands of devices using SNMP, SSH, ICMP, WMI, and related protocols. Own testing, troubleshoot issues across application, operating-system, and network layers, optimize reliability and performance, and collaborate with backend, UI, QA, and product teams.

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.

Design, develop, and optimize high-performance C++ systems software for Linux-based manufacturing intelligence platforms. Build multithreaded and asynchronous architectures, profile performance, debug software-hardware issues, maintain Python tooling, and collaborate with firmware, hardware, and application teams throughout the product lifecycle.

As a Sr. Software Engineer at Bloomerang, you will lead technical direction, mentor engineers, and enhance SaaS solutions while utilizing .NET and AI tools. You will ensure scalable, maintainable applications, advocate for Agile workflows, and focus on quality outcomes in software development.

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.

Design, implement, test, and modernize backend services and integrations (TypeScript/Node.js and C++). Lead large projects, write technical specifications and API contracts, enforce coding standards, coach engineers, and drive legacy-to-modern migrations within online banking and core systems.

Design, build, and maintain Stellar Core, the distributed system powering the Stellar blockchain ledger and consensus. Develop scalable, resilient components; improve peer-to-peer networking and processing performance; investigate bottlenecks; and contribute to architecture, code reviews, RFCs, formal verification, simulations, and open-source collaboration. The role requires production C++ or Rust expertise, strong software design skills, and ownership of core subsystems.

Leads and develops a software engineering team while contributing hands-on to enterprise application design, coding, testing, code reviews, production support, and technical decisions. Builds scalable solutions using C#, ASP.NET, SQL Server, and modern web technologies; partners with product and business stakeholders; supports Agile delivery, CI/CD, troubleshooting, root cause analysis, and engineering best practices. The role also includes mentoring engineers, monitoring delivery and operational metrics, and driving continuous improvement.

Design, develop, and field high-performance Ground Control Station and C2 software using C++/Qt/QML and QGroundControl. Lead architecture and technical direction, mentor engineers, define APIs/ICDs, debug integration/latency issues, support field tests, implement post-mission debrief tools, and ensure interoperability with C2 standards.

Leads hands-on full-stack development across architecture, implementation, testing, deployment, and support. Designs secure, scalable C#/.NET and Angular applications, cloud integrations, APIs, and data solutions on AWS. Guides developers, establishes engineering standards, manages CI/CD and automated testing, troubleshoots complex issues, and drives cloud optimization, security, and technical debt reduction. Collaborates with product, architecture, DevOps, analytics, and project teams while supporting migration of on-premises applications to AWS.

Lead a development team while remaining hands-on in full-stack engineering. Design, build, test, deploy, and support secure web applications using C#/.NET, Angular, databases, and AWS. Drive cloud migrations, architecture, CI/CD automation, application security, troubleshooting, performance and cost optimization. Mentor developers, establish engineering standards, lead technical delivery, and collaborate with product, data, DevOps, and architecture teams.

Lead end-to-end development of secure, scalable web applications and data solutions supporting clinical trial operations. Design frontend and backend components using C#/.NET, Angular, AWS, and relational or non-relational databases. Guide architecture, testing, deployment, CI/CD, security, cloud optimization, and regulatory compliance. Mentor developers, oversee technical delivery, troubleshoot complex issues, and lead migration and modernization of on-premises applications to AWS.

Build and optimize high-performance C/C++ and Rust server applications and feed handlers for market data. Implement parsers, petabyte-scale processing tools, and low-latency, high-throughput optimizations. Collaborate on build/deploy/CI, monitoring, and ensure reliable feature rollouts.

Design and develop low-latency, high-throughput distributed database kernels for massively parallel analytics. Responsibilities include query execution, columnar storage, transaction management, cluster coordination, hardware-aware optimization, SIMD vectorization, RDMA networking, in-database machine learning, vector indexing, performance tuning, architecture reviews, code reviews, mentoring, and resolving scalability issues.

Develop and maintain the Java client library and high-performance C/C++ server applications. Implement message parsers and feed handlers, optimize for extreme throughput and low latency, build tools for petabyte-scale processing, collaborate on build/deploy/CI practices, monitor uptime, and support smooth feature rollouts.

Implement and maintain the C# client library and high-performance C++ server applications. Build message parsers and feed handlers, optimize for millions of messages/second and nanosecond latency, develop petabyte-scale data tools, collaborate on build/deploy/CI/CD, monitoring, and ensure reliable feature rollouts.

Develop high-performance client-side systems in C++/WebAssembly, optimize multiplayer protocols, and collaborate on impactful features for Figma's design platform.

Develop user interface components for ArcGIS Pro using C# and WPF, work in an agile team, and design software solutions for raster and imagery processing.

You will develop and maintain components of the LLVM based toolchain, collaborating with the community while ensuring platform-specific optimizations and tests.

Design, build, and implement changes to Stellar Core while working on performance improvements, decentralization, and incentive mechanics. Collaborate on architectures and contribute to code reviews under the Stellar Development Foundation.

Design and develop key components of Stellar Core while collaborating with team members. Engage in performance optimization and ensure the system's scalability and security.

Design and optimize high-performance C++/CUDA libraries for GPU-based data processing. Improve multi-node GPU communication (UcxExchange), optimize Presto GPU query performance, and lead enhancements across Presto, Velox, and cuDF projects for efficient DataFrame and database acceleration.

Develop and optimize ultra-low-latency, high-performance trading infrastructure in modern C++. Implement and tune order execution, market data connectivity, multi-threaded systems, and risk modules. Profile and benchmark real-time systems, collaborate with quants and traders, and maintain robust, fault-tolerant continuous trading operations.