Backend API Developer

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.

• 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.

• 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.

• Deliver updates using server-sent events and Web Socket streams.
• Manage connection lifecycle, authentication, back pressure, reconnection, and catch‑up.
• Sustain large numbers of concurrent long‑lived connections without degradation.

• 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.

• 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.

• 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.

• 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.

• 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 back pressure.
• 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).

• 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.

• Growth: AI-powered career tool that identifies career steps and learning opportunities
• Support:
  An internal mobility team focused on helping you achieve your career goals
• Rewards:
  Comprehensive benefits and wellness packages, 401K with company match, and competitive pay and paid time off
• Community:
  Award‑winning culture of innovation and a military‑friendly workplace

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.