Overview
Skills
Job Details
Senior Java Reactive Engineer
Location: Phoenix, Arizona (Hybrid/Onsite depending on team needs)
Role Overview
American Express is looking for a Senior Java Engineer with strong experience in reactive systems to build and evolve high‑throughput, low‑latency platforms. This role focuses on designing and developing scalable backend services using Java, Vert.x and/or Reactive Programming with Spring Boot, supporting mission‑critical payment and financial services.
You will work closely with product managers, architects, and fellow engineers to deliver resilient, cloud‑ready solutions that operate at enterprise scale.
Key Responsibilities
Design, develop, and maintain reactive, event‑driven microservices using Java
Build high‑performance applications using Vert.x and/or Spring Boot with reactive frameworks (WebFlux, Project Reactor, RxJava)
Develop RESTful and asynchronous APIs with a focus on scalability, resilience, and performance
Apply reactive design patterns for non‑blocking I/O and distributed systems
Collaborate in an Agile environment with cross‑functional teams
Ensure code quality through reviews, unit testing, and automated testing practices
Monitor, troubleshoot, and optimize applications in production environments
Contribute to architecture decisions and technical roadmaps
Required Qualifications
Strong experience in Java backend development
Hands‑on experience with Vert.x or Reactive Programming using Spring Boot
Solid understanding of asynchronous, non‑blocking, and event‑driven architectures
Experience building and consuming REST APIs
Familiarity with microservices architecture
Strong knowledge of concurrency, multithreading, and performance optimization
Experience with relational and/or NoSQL databases
Proficiency with Git and CI/CD pipelines
Preferred Qualifications
Experience with cloud platforms (AWS, Azure, or Google Cloud Platform)
Knowledge of containerization and orchestration (Docker, Kubernetes)
Experience in financial services or high‑transaction systems
Familiarity with messaging systems such as Kafka or RabbitMQ
Exposure to observability tools (logging, monitoring, tracing)