GIS Developer (Onsite)

Contract: NATO; Geo & Space Services Section (Contingent upon NATO acceptance of Candidate) Work Location: NATO Headquarters in Brussels, Belgium Reporting Hours: Central European Business Hours Work Location: Onsite Monday through Friday at NATO Headquarters in Brussels, Belgium Clearance: DoD Secret Clearance or NATO Secret Clearance Travel: No anticipated travel at this time Candidates will not be accepted after October 9th. Geo cgi is seeking an experienced GIS Developer to support the NATO International Staff (IS) Operations Division, Situation Centre (SITCEN), Geo & Space Services Section at NATO Headquarters in Brussels, Belgium. This role will support the development, modernization, and maintenance of web-based GIS applications used to provide geospatial information in support of NATO senior decision-makers, intelligence analysts, task forces, exercises, and other mission-critical activities. Working closely with the GIS Project Manager, the GIS Developer will design, develop, and deploy secure web GIS applications; integrate spatial data and services; develop geospatial processing and automation workflows; and support the performance and maintainability of NATO GIS applications. The ideal candidate brings strong web development experience using modern JavaScript frameworks, hands-on experience with the ArcGIS Maps SDK for JavaScript or similar web mapping technologies, and proficiency with Python-based geospatial processing and automation. This position must be performed 100% onsite at NATO Headquarters in Brussels, Belgium. Key Responsibilities: Design, develop, configure, and maintain web-based GIS applications using the ArcGIS Maps SDK for JavaScript and modern web development frameworks. Implement and enhance web mapping functionality, including layer management, popups, custom widgets, and client-side spatial operations. Integrate classified and unclassified spatial data and services into secure web-based GIS applications. Integrate spatial data services through REST APIs and develop geospatial data models, layers, and map services. Develop Python-based geoprocessing, automation, data conversion, preprocessing, and ETL workflows. Build and maintain backend services and processing pipelines that expose geospatial functionality to web applications and enterprise systems. Configure and manage map services, feature layers, and tiled datasets to support reliable and performant web delivery. Perform performance tuning of backend queries, spatial services, and map rendering. Maintain compliance with application security, usability, and accessibility requirements. Develop and maintain technical documentation for application code, service endpoints, workflows, and system architecture. Provide technical knowledge transfer and application support to NATO personnel. Collaborate with the GIS Project Manager and Geo & Space Services Section staff to troubleshoot issues, implement requirements, and…