CareerPlan

Backend Developer (Java)

Warsaw, PolandFull-time2026-10-05 → 2026-10-27
Hybrid

Core

Developing and maintaining high-availability, high-volume, low-latency Java applications and scalable microservices for a global messaging platform handling over 1 billion messages daily.

Role type

Senior Backend Developer (Java)

Builds

Scalable microservices, high-traffic applications, and core platform features for millions of users.

Domain

Internet / Messaging / Distributed Systems

Required skills

Java (advanced), Reactive/Async frameworks (Vertx, Rxjava, Akka), NoSQL databases (Couchbase, MongoDB), Microservices architecture, Docker, Kubernetes, Unit testing, Cloud technologies

Preferred skills

JavaScript, Python, Remote team collaboration

Technologies

Java, Vertx, Rxjava, Akka, Couchbase, MongoDB, Docker, Kubernetes, Cloud services

Responsibilities

Designing and developing high-availability Java applications; Optimizing performance and ensuring data security; Collaborating with Product and Architects on mission-critical systems; Investigating alternatives and technologies for architectural review.

Seniority

Senior, hands-on IC