Top Senior C# Jobs in Portland, ME

Senior Backend Engineer responsible for designing and building backend services and microservices for payment products. Work includes C++/C#/Java development, REST APIs, Informix/Postgres data stores, CI/CD, cloud deployments, encryption, TDD, and collaborative agile delivery with ownership of architecture and operational quality.

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.

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.

Lead a team to develop SaaS solutions while coding and mentoring engineers. Responsible for technical leadership and team management.

Design and implement high-performance system software for medical devices, collaborating with hardware engineers and ensuring adherence to clinical standards.

Design high-performance C++ libraries for automated PCB design challenges, mentoring peers and shaping technical direction while collaborating with experts in various fields.

Design, build, and maintain backend workflow orchestration and state management for analyzer integrations on the ECL platform. Modernize legacy .NET systems, ensure reliable event-driven operations, collaborate with integration, infrastructure, and QA teams, and preserve workflow behavior during knowledge transfer.

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

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.

The Senior C# Developer will lead AI enablement by transforming APIs into an Agent Mesh using C# and the MCP, ensuring secure AI interactions through Gravitee management.

The Senior Software Engineer will develop and maintain client-side applications, improve installation workflows, and ensure enterprise deployment support for cybersecurity products.

As a Senior Site Reliability Engineer, you'll analyze and improve software on production networks, automate debugging, and validate cost reductions while collaborating with development and QA teams.