Senior Software Engineer - Backend

Responsibilities 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 Skills 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 Preferred Qualifications: 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 Technology Stack: C# .NET/ASP.NET Core Entity Framework Core SQL Server Microsoft Azure Azure DevOps REST APIs CI/CD Automation The pay range is the lowest to highest compensation we reasonably in good faith believe we would pay at posting for this role. We may ultimately pay more or less than this range. Employee pay is based on factors like relevant education, qualifications, certifications, experience, skills, seniority, location, performance, union contract and business needs. This range may be modified in the future. We offer comprehensive benefits including medical/dental/vision insurance, HSA, FSA, 401(k), and life, disability & ADD insurance to eligible employees. Salaried personnel receive paid time off. Hourly employees are not eligible for paid time off unless required by law. Hourly employees on a Service Contract Act project are eligible for paid sick leave. Note: Pay is not considered compensation until it is earned, vested and determinable. The amount and availability of any compensation remains in Kforce's sole discretion unless and until paid and may be modified in its discretion consistent with the law. This job is not eligible for bonuses, incentives or commissions. Kforce is an Equal Opportunity/Affirmative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, pregnancy, sexual orientation, gender identity, national origin, age, protected veteran status, or disability status. By clicking "Apply Today" you agree to receive calls, AI-generated calls, text messages or emails from Kforce and its affiliates, and service providers. Note that if you choose to communicate with Kforce via text messaging the frequency may vary, and message and data rates may apply. Carriers are not liable for delayed or undelivered messages. You will always have the right to cease communicating via text by using key words such as STOP. Kforce is a professional staffing services firm offering Technology and Finance & Accounting jobs with top employers nationwide. We specialize in providing contract, contract-to-hire and direct placement opportunities, with over 50 years of experience in the staffing industry. Kforce offers many consultants comprehensive benefits depending on employment status, including medical, dental, 401(K), life insurance and disability. Our vision is to be "the firm most respected by those we serve." Kforce