Senior Java Developer

Location : Madrid, Spain (3 days / week onsite in city center) Eligibility : EU Citizens or Candidates with a Valid European Work VisaAbout the Role : UST is looking for a Senior Software Engineer with strong expertise in Java and Cloud-native platforms.

As a Senior Software Engineer, you'll take technical ownership of critical systems and drive architectural direction across multiple teams.

In our agile, Dev Ops - centric environment, you'll lead the end-to-end lifecycle of high-impact services- shaping design, delivery, and operations - while mentoring engineering leads and influencing best practices at scale.Key Responsibilities : Technical Strategy & Architecture : define and evolve the architecture for large-scale, microservices-based systems : Lead cross-team design reviews, ensuring alignment with performance, security, and scalability goals.Dev Ops & Delivery Excellence : Architect and optimize CI / CD pipelines for complex, multi-team workflows.

Champion observability, resilience, and "everything as code" across infrastructure and deployments.Feature Leadership & Stakeholder Partnership : Own the delivery of major features, coordinating with Product, UX, and Operations to meet business objectives.

Act as a senior technical liaison for stakeholders, translating strategic goals into actionable roadmaps.Quality & Engineering Standards : Establish and enforce coding standards, testing requirements (TDD / BDD), and performance benchmarks.

o Introduce and evangelize new tools, frameworks, and processes that elevate team productivity and code quality.Mentorship & Organizational Impact : Mentor senior and mid-level engineers—guiding career growth, architectural thinking, and technical decision-making.

o Lead brown-bags, hackathons, and guild meetings to foster a culture of continuous learning and innovation.Mandatory Requirements : years building and scaling distributed systems in agile / Dev Ops organizations.Expert in Java, Spring Boot, RESTful microservices, and event-driven architectures (Kafka, Avro).Strong frontend acumen with React, Java Script / Type Script, and API-first integration (Open API).Deep familiarity with Kubernetes orchestration, container security, and infrastructure as code.English level : C1 (professional fluency).What We Offer : Annual Leave : 23 days + 24th and 31st December as discretionary holidays.Flexible Compensation Options : Meals, transport, kindergarten, online English lessons, and more.Work-Life Balance : Remote / hybrid model, flexible hours, and compacted summer schedules.Relocation Package : will be covered by the company side.Employee Benefits : Private health insurance, accident insurance, and connectivity support.Training Access : Free access to leading training platforms and continuous learning opportunities.Referral Bonuses : Earn rewards when you refer qualified professionals.Salary Payment Choice : Opt between 12 or 14 payments annually.Wellbeing Extras : Discounts on gyms and UST Club partner deals.Inclusion & Diversity at USTWe believe in equal opportunities and encourage applications from all backgrounds.

We are especially committed to hiring individuals with a disability certificate as part of our inclusion goals.