Senior Java Developer – Transit & Mobility Platform (Project-Based, Remote)

About the RoleWe are seeking an experienced Senior Java Developer to join our team on a project-based contract to build a modern, scalable transit and mobility platform with native mobile applications for iOS and Android. This system will integrate multiple data sources, process real-time transit information, and provide both operator-facing and public-facing features accessible via web and mobile.The selected candidate will work remotely and be supervised directly by our Chief Information Officer (CIO). Compensation will be milestone-based, linked to the successful completion of specific deliverables.Key ResponsibilitiesDesign, develop, and maintain modular Java applications for transit data management and user interaction.Implement GTFS and GTFS-RT standards for public transportation data.Integrate APIs and external services for real-time vehicle tracking, trip planning, and schedule updates.Optimize backend performance to handle high-volume, real-time requests.Collaborate with mobile developers to ensure seamless integration with iOS and Android apps.Oversee deployment processes to both Apple App Store and Google Play Store.Collaborate with our CIO to align development with project goals and milestones.Participate in testing, debugging, and deployment of the platform.Required Skills & ExperienceExpert-level proficiency in Java (Spring Framework, Maven, etc.).Strong experience in backend system architecture and API development.Proven track record working with public transit data standards (GTFS, GTFS-RT).Familiarity with real-time data processing and message broker technologies (e.g., Kafka, RabbitMQ).Knowledge of PostgreSQL/MySQL and spatial databases (PostGIS a plus).Experience integrating mapping libraries and geospatial APIs (e.g., OpenStreetMap, Leaflet, Mapbox).Demonstrated history of contributing to or maintaining open source projects.Proven collaboration with mobile app teams for iOS and Android integration.Familiarity with deployment and CI/CD pipelines for mobile app stores.Excellent communication skills in English or Spanish.Preferred QualificationsPrevious work on public transportation or mobility platforms.Experience with containerized deployments (Docker, Kubernetes).Familiarity with cloud environments (AWS, GCP, or Azure).Understanding of microservices architecture.Project DetailsType: Contract – Project-BasedLocation: RemoteSupervision: Directly by Company CIOCompensation: Milestone-based (paid per deliverable)Estimated Duration: To be defined during onboarding, based on project scopeIf you are passionate about mobility solutions, real-time systems, and scalable backend architectures — and are looking for a challenging project where your work directly impacts users — we’d like to hear from you.How to Apply:Send your CV, portfolio, and examples of relevant work to careers@smartech.pr with the subject line: “Senior Java Developer – Mobility Platform”.