Java Developer

Role Overview

Marfeel is hiring a Java Developer to join a small, high-ownership engineering team working on new product initiatives. You’ll build new backend services and features while navigating and improving existing codebases, owning backend architecture decisions and partnering closely with product and data.

Responsibilities

• Work on challenging, high-concurrency systems impacting millions of users.
• Deliver backend features end to end: design, build, ship, run, and fix in production.
• Own backend architecture decisions for reliable, high-performance services at scale.
• Build using modern stack and tooling, including automated continuous delivery and instrumented deployments.
• Use AI coding tools (e.g., Claude Code) as a core workflow and improve skills and internal tooling around them.
• Operate in an agile environment with weekly sprints and iterative development.
• Participate in technical decisions and collaborate cross-functionally; step into other layers when needed.

Requirements

• Strong ownership mindset: debug issues yourself and communicate escalation context clearly.
• Deep understanding of reactive programming: non-blocking I/O, backpressure, and when reactive approaches are appropriate.
• Deep knowledge of Java and parallel/concurrent execution.
• Solid experience with the Spring ecosystem:
  • Spring IoC, Spring MVC, Spring WebFlux
  • Spring Data, R2DBC
• Strong OO principles and design patterns; keep designs simple.
• Clean code practices and comfort with iterative development.
• Experience with relational and/or non-relational databases.

Nice to Have

• Experience deploying and operating large applications.
• Microservices experience using Docker and Kubernetes.
• Experience with any of:
  • Nginx, Tomcat, MongoDB
• In-depth Spring, including Spring Security.
• Experience with ClickHouse or other OLAP stores.

Remote / Location

• Option to work full remote.
• Location listed: United States.