Java Engineer

Senior Java Engineer — Spring Boot Reactive (BFF / Channel Layer)

About the Role

An exciting opportunity for a Senior Java Engineer to join a high-performing engineering team responsible for building Backend-for-Frontend (BFF) services within a modern digital platform.

This role focuses on developing reactive, non-blocking microservices that sit between customer-facing channels (web, mobile, third-party integrations) and downstream systems.

You will play a key role in delivering high-performance, resilient, and secure APIs that directly impact user experience at scale.

Key Responsibilities

BFF & API Layer

• Design and build BFF services that aggregate and orchestrate downstream APIs

• Tailor responses for different channels (web, mobile, conversational interfaces)

• Define and evolve consumer-driven API contracts

Reactive Development

• Build services using Spring Boot 3.x, WebFlux, and Project Reactor

• Apply non-blocking, asynchronous programming models

• Ensure optimal handling of backpressure and concurrency

Resilience & Performance

• Implement resilience patterns using Resilience4j

• Apply caching strategies (Redis, Caffeine)

• Optimize for low latency and high throughput

Integration & Messaging

• Integrate with distributed systems via REST and messaging platforms

• Use Kafka or RabbitMQ for event-driven processing

Security

• Implement OAuth2 / OpenID Connect and JWT-based security

• Enforce API protection, validation, and rate limiting

Testing & Quality

• Develop comprehensive test coverage:

  • Unit testing (JUnit, Mockito)

  • Integration testing (Testcontainers)

  • Reactive testing (StepVerifier)

  • Contract testing

Cloud & DevOps

• Containerise applications using Docker

• Deploy via Kubernetes and CI/CD pipelines

• Contribute to automation and infrastructure practices

Observability

• Implement logging, tracing, and monitoring

• Use tools such as Micrometer, OpenTelemetry, Prometheus, Grafana

Collaboration & Leadership

• Participate in architecture and design discussions

• Conduct code reviews and enforce best practices

• Mentor engineers and contribute to team growth

Required Skills & Experience

• Strong experience in Java 17+

• Deep expertise in Spring Boot and Spring WebFlux

• Solid understanding of reactive programming paradigms

• Experience with BFF / API composition patterns

• Messaging systems (Kafka / RabbitMQ)

• Containers and cloud platforms (Docker, Kubernetes)

• CI/CD and modern DevOps practices

• Redis, R2DBC, and/or NoSQL databases

Preferred Experience

• 6–10 years of software engineering experience

• 3+ years working with reactive systems

• Experience in high-scale distributed environments

• Exposure to regulated or security-sensitive domains

• Familiarity with API gateway ecosystems

Key Traits

• Strong engineering craftsmanship and attention to detail

• Passion for reactive and scalable systems

• Customer-focused mindset

• Collaborative and team-oriented

• Strong problem-solving ability in distributed systems

• Ownership and accountability

• Continuous learner with a growth mindset

Why Join

• Build high-impact, large-scale systems

• Work with modern, cloud-native technologies

• Be part of a collaborative, high-performing team

• Influence architecture and engineering practices

• Grow both technically and professionally