Backend Developer

This role is suitable for a Senior Backend Engineer or strong Middle-level developer with at least three years of production experience, preferably with full-stack exposure. The candidate should be skilled in Java, Spring, reactive programming, RESTful APIs, Java EE, messaging systems such as NATS, microservices, automated unit testing, and ATDD/BDD, with strong communication and Agile collaboration abilities. They should be familiar with owning architecture and technical design, building scalable high-throughput services, implementing event-driven systems, integrating frontend and backend components, and translating complex business requirements into reliable solutions.

How would you design a reactive RESTful service using Java and Spring WebFlux?

I would model the service around non-blocking I/O, reactive types such as Mono and Flux, and clear separation between controllers, application services, and repositories. I would also enforce timeouts, backpressure, centralized error handling, observability, and avoid blocking calls on reactive event-loop threads.

What are the main differences between Spring MVC and Spring WebFlux?

Spring MVC uses a traditional thread-per-request model, while WebFlux is designed for non-blocking, event-driven execution. WebFlux is particularly useful for high-concurrency workloads and reactive data sources, but blocking dependencies must be isolated or replaced.

How would you design a scalable REST API for reference and configuration data?

I would define resource-oriented endpoints, explicit validation, consistent error contracts, pagination where needed, and versioning for compatibility. I would also consider caching, idempotency, authorization, auditability, and database indexing based on expected access patterns.

How would you use NATS in an event-driven microservices architecture?

I would use NATS subjects to publish domain events and subscribe consumers based on clear ownership boundaries. For reliability, I would define delivery and retry requirements, use durable consumers where applicable with JetStream, make handlers idempotent, and monitor lag, failures, and redeliveries.

How do you prevent blocking operations from degrading a reactive application?

I identify blocking database drivers, file operations, or third-party clients and replace them with reactive alternatives when possible. If blocking work is unavoidable, I isolate it on a bounded scheduler and protect the system with timeouts, bulkheads, and monitoring.

How would you apply ATDD or BDD to complex cross-border processing rules?

I would express business behavior as concrete Given-When-Then scenarios created with domain stakeholders before implementation. These scenarios become automated acceptance tests covering normal flows, country-specific rules, validation failures, boundary conditions, and changes to configuration data.

What testing strategy would you apply to a Spring-based backend?

I would combine focused unit tests for domain logic with integration tests for persistence, messaging, and external APIs. Contract tests would validate REST and event interfaces, while testcontainers or equivalent infrastructure could provide realistic dependencies without relying on shared environments.

How would you ensure consistency and reliability when updating configuration data?

I would use transactional updates, optimistic locking, schema and input validation, and versioned configuration where historical traceability is required. Events should be published reliably using an outbox or equivalent pattern so downstream systems do not miss committed changes.

How would you integrate an Angular frontend with a reactive backend?

I would define stable, documented API contracts and return consistent response and error formats that Angular services can consume predictably. I would also address authentication, CORS, pagination, caching, request cancellation, and loading or retry behavior for reactive user experiences.

What practices would you follow when deploying Java microservices to the cloud?

I would package services consistently, externalize configuration and secrets, implement health and readiness checks, and use automated CI/CD pipelines. Production readiness would also include centralized logs, metrics, distributed tracing, autoscaling policies, secure networking, and controlled rollout or rollback strategies.

MOOVX is a global IT services company seeking a Backend Developer to build scalable systems for domestic and cross-border processing alongside international engineering teams. You’ll own architecture and design initiatives, develop REST APIs and messaging solutions, integrate reactive backends, and champion ATDD/BDD and automated testing. The stack includes Java, Spring, reactive programming, REST, NATS, with Angular, Drools, Oracle, and cloud platforms as valuable extras. This is a 100% remote, full-time role open across LATAM, offering a competitive salary in USD and the opportunity to make a visible impact within a collaborative, fast-growing team.