SANTANDER - R&C Senior Java Developer

We are looking for a senior Java engineer to join a backend platform team building high-throughput, distributed services. You will design and ship production

code and own non-trivial pieces of the architecture end-to-end.

Responsibilities

• Design and build services in modern Java (21), with a strong bias for correctness, observability, and operability.

• Own features end-to-end — from API contract design through implementation, testing, rollout, and on-call ownership.

• Drive technical decisions on concurrency, streaming, data modeling, and inter-service communication; document the trade-offs.

• Mentor mid-level engineers through pairing, design reviews, and detailed code review feedback.

• Improve the developer experience — local-dev tooling, build times, test reliability, and CI/CD pipelines.

• Partner with adjacent teams (product, SRE, data, downstream consumers) to negotiate interfaces and timelines.

Required Skills

• 8+ years of professional Java, with 3+ years on Java 17 or 21 (records, sealed types, pattern matching, virtual threads where appropriate).

• Deep Spring / Spring Boot experience in production services.

• Reactive programming with Project Reactor or RxJava (Mono/Flux, backpressure, retry/backoff, hot vs cold publishers) — or strong async fluency with

CompletableFuture and structured concurrency.

• gRPC + Protobuf in production: streaming RPCs, deadlines, interceptors, schema evolution.

• Strong concurrency fundamentals: thread-safety reasoning, executor sizing, lock-free patterns, lifecycle ownership of long-lived threads.

• Testing rigor: JUnit 5, Mockito, AssertJ; integration tests against real dependencies; contract / parity testing.

• Streaming and storage: Kafka consumer/producer semantics; one of Redis, Postgres, or MongoDB at production scale.

• Cloud fluency: AWS (or equivalent) — S3, IAM, managed Kafka, container runtimes.

• Excellent written communication. You can write a design doc, a postmortem, and a useful PR description.

• MINIMUM LEVEL OF ENGLISH C1

Nice to Have

• Experience leading a non-trivial migration or refactor across a multi-module codebase.

• Container packaging and multi-arch image builds (linux/amd64, linux/arm64).

• Python familiarity — reading it comfortably, debugging it when needed.

• Apache Arrow or columnar data format experience.

• TeamCity, GitHub Actions, or comparable CI/CD pipeline ownership.