Backend API Developer

Job Description: Type of Requisition: Regular Clearance Level Must Currently Possess: None Clearance Level Must Be Able To Obtain: None Public Trust/Other Required: NACI (T1) Job Family: Data Science and Data Engineering Skills: Job Qualifications: Back-End Development, Building Operations, Cloud Delivery, Design Development, Network Gateway Certifications: None Experience: 8 + years of related experience US Citizenship Required: Yes Job Description: Position Summary The Backend API Developer builds and operates the service layer behind an operator application in a cyber command center supporting national cyber defense across Critical Infrastructure and government partners. Responsibilities focus on low‑latency service delivery, correctness under load, and strict entitlement enforcement. Key Responsibilities Service Design & Development Build and operate independently deployable services behind the application. Maintain interface contracts, versioning, and backward compatibility. Implement consistent request handling, validation, errors, authentication, and authorization. Create automated tests for service behavior and contract compliance. Upstream Integration & View State Integrate with upstream services via REST and streaming interfaces. Maintain accurate, consistent view state and ensure clients connecting mid‑stream receive a complete picture. Coordinate payload and interface changes with upstream service owners. Real-Time Delivery Deliver updates using server-sent events and WebSocket streams. Manage connection lifecycle, authentication, backpressure, reconnection, and catch‑up. Sustain large numbers of concurrent long‑lived connections without degradation. Authorization & Content Filtering Enforce role and attribute-based authorization server‑side. Implement content filtering so users receive only authorized data. Test entitlement enforcement and maintain audit logs of all deliveries. Event-Triggered Services Build and operate event-triggered functions for routing, downstream actions, and notifications. Integrate with managed messaging services. Ensure triggered actions are idempotent, observable, and safely retried. Performance, Reliability & Operations Design and validate services for low-latency, high-throughput use. Instrument services for monitoring, diagnosis, and production incident response. Deploy through established pipelines into containerized environments. Maintain required training and certifications; report certification status monthly. Collaboration Collaborate with front-end engineers on service contracts. Work with platform teams on configuration, scaling, secrets, and deployment. Participate in sprint planning, demos, and reviews. Required Qualifications Experience building and operating production service interfaces at scale. Experience integrating with upstream services and maintaining derived state. Knowledge of push/streaming delivery, connection lifecycle, and backpressure. Experience with server-side authorization models. Experience with containerized deployment and cloud environments. Experience instrumenting services and supporting production incidents. BS in computer science or engineering and 8+ years relevant experience (or equivalent). Public Trust eligibility and U.S. citizenship. On-site work in the Washington, D.C. metro area (not remote or hybrid). Preferred Qualifications Experience with streaming platforms (Kafka, MSK, Event Hubs). Experience with API gateways or service meshes. Experience with serverless functions (Lambda, Azure Functions). Experience supporting latency‑sensitive operational systems. Experience delivering software in regulated environments. Current cloud developer/associate certification. GDIT Is Your Place At GDIT, the mission is our purpose, and our people are at the center of everything we do. Growth: AI-powered career tool that identifies career steps and learning opportunitiesSupport: An internal mobility team focused on helping you achieve your career goalsRewards: Comprehensive benefits and wellness packages, 401K with company match, and competitive pay and paid time offCommunity: Award-winning culture of innovation and a military-friendly workplace Own Your Opportunity Explore a career in data science and engineering at GDIT and you’ll find endless opportunities to grow alongside colleagues who share your determination for solving complex data challenges. The likely salary range for this position is $119,000 - $161,000. This is not, however, a guarantee of compensation or salary. Rather, salary will be set based on experience, geographic location and possibly contractual requirements and could fall outside of this range. Scheduled Weekly Hours: 40 Travel Required: Less than 10% Telecommuting Options: Onsite Work Location: USA VA Arlington Additional Work Locations: Total Rewards At GDIT: Our benefits package for all US-based employees includes a variety of medical plan options, some with Health Savings Accounts, dental plan options, a vision plan, and a 401(k) plan offering the ability to contribute both pre and post-tax dollars up to the IRS annual limits and receive a company match. To encourage work/life balance, GDIT offers employees full flex work weeks where possible and a variety of paid time off plans, including vacation, sick and personal time, holidays, paid parental, military, bereavement and jury duty leave. To ensure our employees are able to protect their income, other offerings such as short and long-term disability benefits, life, accidental death and dismemberment, personal accident, critical illness and business travel and accident insurance are provided or available. We regularly review our Total Rewards package to ensure our offerings are competitive and reflect what our employees have told us they value most. Our Identity Verification Process: As part of the hiring process, we will ask you to complete an identity verification process that leverages advanced biometrics and artificial intelligence to ensure authenticity and protect against identity fraud. You are expected to be on camera during virtual interviews. We reserve the right to take your picture to verify your identity and prevent fraud. By proceeding, you authorize the collection, processing, and use of your biometric data for identity verification and security purposes. About Our Work: We are GDIT. A global technology and professional services company that delivers technology solutions and mission services to every major agency across the U.S. government, defense and intelligence community. Our 26,000 experts extract the power of technology to create immediate value and deliver solutions at the edge of innovation. We operate across 50+ countries worldwide, offering leading mission-ready capabilities in AI, cloud, cyber and software development. Join our Talent Community to stay up to date on our career opportunities and events at gdit.com/tc. Equal Opportunity Employer / Individuals with Disabilities / Protected Veterans