Senior Software Engineer - Backend

Kforce's client is looking to add a Senior Software Engineer to their team. This role is a 6-month contract to hire in Saint Louis, MO. Summary: Are you a back-end engineer who loves solving complex technical challenges at scale? Our client is seeking a Senior Software Engineer to design, build, and optimize the core services that power a high-volume platform. This role is focused entirely on back-end development using the Microsoft technology stack, including C#, .NET, SQL Server, and Azure. This is an opportunity to work on highly performant, rules-driven systems where scalability, reliability, and code quality are critical. You'll partner with Product, QA, and Engineering teams to develop solutions that support complex business logic while helping drive architectural decisions and technical best practice. What You'll Do:

• Design, develop, and maintain back-end services using C#, .NET, ASP.NET Core, and Azure
• Build and optimize high-performance APIs and services focused on scalability and reliability
• Profile and tune application performance, including latency, memory usage, database efficiency, and throughput
• Design cloud-native solutions leveraging Azure services, messaging, caching, and automation tools
• Translate complex business requirements into clean, maintainable code and scalable architectures
• Participate in code reviews, technical design discussions, and architecture decisions
• Troubleshoot and resolve complex production issues in large-scale systems
• Mentor other engineers and contribute to raising technical standards across the team
• Leverage AI-assisted development tools to improve efficiency, quality, and delivery
• Bachelor's degree in Computer Science, Software Engineering, or related field (or equivalent experience)
• 7+ years of professional software development experience
• Experience optimizing application performance, identifying bottlenecks, and improving scalability
• Advanced SQL Server experience, including query optimization and performance tuning
• Experience developing and supporting cloud-based applications in Microsoft Azure
• Strong expertise with C#, .NET, ASP.NET Core, and RESTful API development
• Deep understanding of software design patterns, object-oriented design, and domain modeling
• Strong understanding of automated testing, CI/CD pipelines, and DevOps practices

• Experience building high-throughput, low-latency applications
• Experience with Infrastructure as Code and containerized deployments
• Knowledge of distributed systems, caching strategies, messaging platforms, and event-driven architectures
• Exposure to AI-assisted software development tools
• Background in financial services or other regulated industries

• C#
• .NET/ASP.NET Core
• Entity Framework Core
• SQL Server
• Microsoft Azure
• Azure DevOps
• REST APIs
• CI/CD Automation