Lead Java Engineer

N-iX is looking for Lead Java Engineer for a global technology company serving large enterprises with mission-critical SaaS products in the brand protection and domain management space. The Client is consolidating multiple client portals into a single modern platform on AWS, with migration of existing clients onto it. The work spans application development, cloud infrastructure, and platform reliability as the new system scales. Requirements 7+ years of commercial Java engineering experience, including a technical leadership role on complex backend systems Strong hands-on expertise with Java 21, and comfort working with older Java versions in legacy code Deep expertise across the Spring ecosystem — Spring Boot, Spring MVC/Web, Spring Security, Spring Data JPA, JDBC, Spring Session, Actuator Solid experience with RabbitMQ and event-driven / asynchronous messaging Experience with Redis (caching, sessions) Strong relational database and SQL skills — data modeling, schema design, query optimization Working experience with AWS Proven track record designing and integrating REST APIs and distributed services Significant experience with data migration, ETL, or system integration at scale Strong testing discipline and a quality-first mindset — unit and integration testing Ability to own technical decisions, set standards, and mentor other engineers Ability to lead architecture and work-breakdown sessions and translate ambiguous business needs into a clear technical plan Build tooling with Maven Ability to work embedded within a client's team as part of a close partnership Ability to work with significant overlap with US Mountain Time, especially during ramp-up — distributed team across US / UK / Brazil Excellent English communication skills Experience working in Agile / Scrum / Kanban Tech stack: Java 21 (some older versions in legacy services), Spring Boot, Spring MVC/Web, Spring Security, Spring Data JPA, JDBC, Spring Session, Actuator, Redis, RabbitMQ, Maven. Responsibilities Lead the design and delivery of core backend services and data migration components Own the design of integration and synchronization logic between legacy and new systems Drive architecture and work-breakdown sessions; define, estimate, and sequence the work with the Client's senior engineers Set engineering standards and best practices; mentor and guide other engineers on the team Ensure strong test coverage and quality across the codebase Troubleshoot production and integration issues and lead root-cause analysis Participate in and lead code reviews, maintaining code quality standards Engage with Client engineering counterparts in US / UK / Brazil on integration points and delivery milestones Participate in Agile ceremonies (stand-ups, planning, retros, demos) Nice to Have Experience with AI-assisted development tools (Copilot, Claude, Cursor) Background in SaaS, multi-tenant platforms, or large-scale B2B portals Experience leading large-scale data migration between production systems Experience integrating with third-party / external partner systems via asynchronous protocols We offer*: Flexible working format - remote, office-based or flexible A competitive salary and good compensation package Personalized career growth Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more) Active tech communities with regular knowledge sharing Education reimbursement Memorable anniversary presents Corporate events and team buildings Other location-specific benefits *not applicable for freelancers