Senior Fullstack Software Engineer (Backend-focused, Java/Spring Boot)

We are looking for Senior Fullstack Software Engineers (Backend-focused) to join FusionHit’s fast-paced, high-impact environment supporting. In this role, you will lead backend architecture and modernization initiatives for enterprise retail and supply chain systems built on Java/Spring Boot, driving design decisions and elevating engineering standards across teams, while remaining comfortable working across the stack.

You will play a key role in transforming legacy platforms into scalable, maintainable, and performance-driven services while collaborating closely with frontend engineers (working across multiple JS frameworks), DevOps, and product stakeholders.

This project focuses on modernizing enterprise-level retail systems that directly support business-critical store and supply chain operations.

Location: Remote – Latin America (must reside and have work authorization in LatAm)

Availability: Significant overlap with Mountain Standard Time (MST)

• BS/MS in Computer Science, Software Engineering, or related field.
• 6+ years of experience in Backend/Fullstack Engineering.
• 5+ years of hands-on experience with Java and Spring Boot building enterprise-grade REST APIs and microservices.
• Strong experience with Postgres-backed data layers and API design for high-traffic retail systems.
• Working knowledge of modern JS/TS frontend frameworks (React, Next.js, Angular, or Vue), sufficient to integrate and troubleshoot end-to-end across our multi-framework frontend stack.
• Strong understanding of phased modernization strategies over legacy backend systems.
• Deep experience with automated testing for backend services (unit, integration, contract) and Playwright/Jest awareness for E2E coordination.
• Experience managing CI/CD pipelines in GitLab.
• Experience implementing monitoring and observability strategies using Datadog.
• Retail, store operations, or supply chain system experience (strong plus).
• Comfortable engaging with stakeholders and incorporating real-world user feedback.
• Excellent communication skills in English (C1 preferred, strong B2 may be considered).

Key Responsibilities

• Lead backend architecture decisions and modernization strategy for Java/Spring Boot services.
• Design scalable, secure REST APIs and microservices on Postgres-backed data stores.
• Drive best practices in code quality, testing, and CI/CD automation.
• Collaborate cross-functionally with frontend, DevOps, and product teams across multiple JS framework stacks.
• Mentor mid-level engineers and promote engineering excellence.
• Ensure performance optimization and monitoring using Datadog.
• Lead phased migration from legacy backend systems to modern service architecture.
• Incorporate stakeholder feedback and real-world retail workflows into system design.