Top C++ Jobs in Philadelphia, PA

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.

Develop and enhance software in C++ on Linux, create analytical tools for financial data, and collaborate with research analysts.

Develop software and enhance systems in C++ on Linux, while collaborating with analysts and engineers to create data processing tools.

Develop and maintain infrastructure for market data feeds, focusing on performance and latency in a real-time financial environment.

Leads instrumentation and controls engineering design for small to medium projects, including programming, planning, detailed design, construction documentation, and administration. Develops automation control systems with controllers, HMIs, workstations, and servers; manages discipline budgets, coordinates clients and project partners, leads quality reviews, supports proposals, performs field surveys, writes specifications, and mentors junior engineers.

Design, develop, and maintain scalable full-stack enterprise applications using C#, .NET, ASP.NET, and Microsoft Azure. Build RESTful APIs and cloud services, modernize existing systems, troubleshoot production issues, and collaborate with technical and business stakeholders. Participate in architecture, code reviews, testing, deployment, and production support while following secure and maintainable development practices.

Evaluate AI coding-agent interactions for usefulness, correctness, engineering judgment, reasoning quality, and developer trust. Provide clear, opinionated feedback, distinguish response-quality levels, and help define standards for excellent interactions with tools such as OpenAI Codex, Claude Code, and Cursor. This contract role requires staff- or principal-level software engineering experience and familiarity with modern AI-assisted development workflows.

Design, build, and maintain scalable full-stack web applications using React, Python, Node.js, and C#. Develop cloud-native AWS solutions with event-driven and serverless architectures, manage relational and NoSQL data stores, write automated tests, maintain infrastructure as code, and contribute to CI/CD pipelines. Collaborate with cross-functional engineering teams on architecture, security, performance, and end-to-end feature delivery in an agile environment.

Develop and maintain end-to-end applications using Python, Node.js, C#, and React. Build scalable backend services, frontend features, APIs, cloud-native AWS solutions, automated tests, infrastructure as code, and CI/CD pipelines. Collaborate with cross-functional engineering teams in an agile, remote environment while contributing to architecture and reliable product delivery for US clients.

The C# / .NET Developer will design and maintain middleware applications, build Shopify integrations, and support a mobile app backend in a remote work environment.

Design and evaluate performance engineering tasks for AI training/evaluation. Optimize runtime, compilers, memory, CPU/GPU and concurrency. Produce documented solutions, evaluate AI-generated code, and build evaluation frameworks and scoring rubrics while collaborating with researchers and SMEs.

Design, implement, and maintain high-quality C++ (C++17/20) robotics software. Improve build systems (CMake), configure GitLab CI/CD, maintain Linux development environments, write unit/integration tests, profile and optimize performance, collaborate with controls and hardware engineers, participate in code reviews, and support tooling and CI infrastructure to keep development fast and reliable.

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.

PrivateID seeks a Principal C++ Engineer with at least 10 years of experience to lead complex systems and scale their platform in a remote-first environment.

Build and maintain scalable, cloud-native APIs using .NET. Enhance core platform components, lead architecture and testing discussions, optimize telemetry and performance, collaborate cross-functionally, conduct code reviews, and mentor team members.

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

Seeking a Senior iOS Developer to design and build high-performance iOS applications. Requires 5+ years in iOS development with Swift and Objective-C, experience with REST services, and skills in data persistence frameworks. Occasional travel may be needed.

Remote backend C# developer to build and optimize a high-load spot-exchange matching engine. Improve performance and API throughput, implement business features, write unit and integration tests, work with .NET Core and PostgreSQL on AWS, and apply multithreading, async, and distributed systems concepts.

Develop and maintain C++ UI applications on UNIX; apply OOP design, database knowledge, and security concepts (SSO, XSS, SQL injection). Lead small teams, work flexible hours, and communicate technical solutions.

Perform civil/structural engineering and design tasks for power plant upgrades and new projects under senior supervision. Assist with calculations, modifications, equipment walkdowns, and design changes to improve plant performance, safety, and reliability. Work involves field and office duties, travel to client sites, and maintaining unescorted nuclear plant access.

Lead technical direction for a major product domain, reduce architectural debt, mentor engineers, standardize AI-agent workflows, and design scalable backend solutions integrating LLMs and cloud services. Drive cross-team RFCs, cookbook standards, and adopt agentic AI tooling while balancing security, quality, and delivery.

Build, integrate, and stress-test full-stack applications and backend services that leverage advanced AI models. Develop production APIs, front-end features, databases, and cloud infrastructure; troubleshoot integrations; prototype rapidly and deliver high-quality code and documentation in fast-moving environments.

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.

Develop and maintain .NET Core trading systems for Linux with service-oriented architecture and multi-threaded processing. Implement async, lock-free structures and distributed systems, write unit and integration tests, optimize SQL queries, design data structures and algorithms, and work with communication protocols (SignalR, gRPC, HTTP). Use PostgreSQL, Docker, and AWS in the deployment stack.

Contribute to and optimize the performance of ClickHouse, assist with debugging, collaborate with teams, and engage with the open-source community.