Senior GraphQL Integration Engineer / Subject Matter Expert (.NET)

Job Title: Senior GraphQL Integration Engineer / Subject Matter Expert (.NET) Location: Washington, DC (Hybrid / Approved Remote) Engagement Type: Full - Time Clearance: Able to obtain Public Trust clearance upon hire About us: At Stackular, we are more than just a team – we are a product development community driven by a shared vision. Our values shape who we are, what we do, and how we interact with our peers and our customers. We're not just seeking any regular engineer; we want individuals who identify with our core values and are passionate about software development Role Overview Stackular is seeking a highly experienced GraphQL Integration Engineer with Subject Matter Expertise to support a federal client’s GraphQL modernization initiative. This role blends hands-on engineering execution with architectural leadership and advisory responsibilities. You will play a critical role in designing, building, and governing a federated GraphQL ecosystem while collaborating with cross-functional teams in a modern .NET-based environment. This position is ideal for professionals who can both write production-grade code and guide architectural decisions at scale. Key Responsibilities Architecture & Advisory • Provide technical leadership on GraphQL federation architecture (Apollo Federation / schema composition) • Define and enforce schema governance, validation, and versioning strategies • Review system architecture, APIs, and GraphQL schemas for scalability and performance • Advise on API security, query optimization, and complexity management • Establish and document best practices and reusable patterns Engineering & Delivery • Design and develop GraphQL subgraphs and APIs using ASP.NET Core and Hot Chocolate • Implement robust data access strategies with PostgreSQL and legacy system integrations • Build and deploy services in containerized environments (Docker, Kubernetes) • Contribute across the full SDLC including design, development, testing, CI/CD, and deployment • Collaborate in Agile teams through sprint planning, code reviews, and retrospectives Integration & Operations • Integrate GraphQL services into CI/CD pipelines (Azure DevOps, Helm) • Ensure compliance with authentication and authorization standards (OAuth2, JWT, Entra) • Optimize performance, observability, and reliability of GraphQL services • Support integration with enterprise and legacy systems Required Skills & Qualifications For 5+ Years (Engineer Level) • 5+ years of experience in backend/API development • Strong hands-on experience with GraphQL (Apollo, Relay, etc.) • Proficiency in Node.js / Java / Python • Experience with REST API integration and microservices • Understanding of API security (OAuth2, JWT, etc.) • Familiarity with databases (SQL/NoSQL) • Experience with version control (Git) and CI/CD pipelines For 10+ Years (SME Level) • 10+ years of experience in API architecture and integration • Deep expertise in GraphQL design patterns, federation, and schema stitching • Strong experience in enterprise architecture and distributed systems • Proven ability to lead large-scale integration programs • Expertise in performance tuning, scalability, and security frameworks • Experience working in federal/government or compliance-heavy environments • Strong stakeholder management and leadership skills Nice to Have • Experience with GraphQL Federation / Apollo Gateway • Knowledge of cloud platforms (AWS, Azure, or GCP) • Exposure to DevSecOps practices • Familiarity with federal standards (e.g., security, accessibility, data privacy)