Java Developer

Role Overview

Join Marfeel as a Java Developer on a small, high-ownership engineering team building new product initiatives. You’ll design and deliver backend services end to end while also navigating existing codebases.

Responsibilities

• Work on challenging backend developments involving high concurrency and impact at large scale (millions of users).
• Own backend features and services end to end: design, build, ship, run, and fix in production.
• Make and own backend architecture decisions in close collaboration with product and data.
• Build and maintain reliable, high-performance microservices.
• Develop in automated CI/CD environments with continuous delivery (Jenkins) and instrumented deployments.
• Use AI coding tools (notably Claude Code) as a core part of your workflow, and improve your tooling and processes.
• Work in an agile environment with weekly sprints and iterative development.
• Contribute to technical decisions and step outside backend when needed.

Requirements

• Strong sense of ownership: debug issues yourself, explain what you tried, and stay accountable.
• Comfortable being the person “on the hook” without heavy process.
• Deep understanding of reactive execution: non-blocking I/O, backpressure, and when reactive is worth the added complexity.
• Deep knowledge of Java and parallel/concurrent code execution.
• Strong Spring experience, including:
  • Spring IoC, Spring MVC
  • Spring WebFlux
  • Spring Data
  • R2DBC
• Solid understanding of web technologies and software built to scale.
• OO principles and design patterns, with ability to keep designs simple.
• Clean code practices and comfort with iterative development.
• Experience with relational and/or non-relational databases.

Nice to Have

• Experience deploying large applications and handling scale-related challenges.
• Microservices experience with Docker and Kubernetes.
• Familiarity with Nginx or Tomcat.
• Experience with MongoDB.
• In-depth Spring Security.
• Experience with ClickHouse or other OLAP stores.