Backend Engineer - AdTech company

EER Poland; Warszawa; Hybrid; PLN 190,000 - 276,000; Full time

Job summary

A leading tech company in Warsaw is seeking a Back-End Developer to design, build, and optimize scalable backend services and APIs. The ideal candidate will have a strong background in Java and Spring Boot, and experience with distributed systems. This position offers a competitive compensation package and the flexibility of a hybrid work model, promoting collaboration in a data-driven environment.

Benefits

Competitive compensation and benefits package

Hybrid work model

Qualifications

• 3+ years of experience in Java development.
• Strong Spring Boot background.
• Proven experience building distributed systems.

Responsibilities

• Design and develop scalable backend applications and APIs.
• Collaborate with cross-functional teams.
• Implement robust logging, monitoring, and alerting.

Skills

Java development

Spring Boot

Distributed systems

Microservices

CI/CD pipelines

Docker

Kubernetes

Performance optimization

Excellent communication

Education

Bachelor’s degree in Computer Science or equivalent

Tools

Prometheus

Grafana

Kibana

JFR

JMeter

Micrometer

New Relic

Datadog

Job description

As a Back-End Developer, you will design, build, and optimize backend services and APIs that power large-scale, data-driven systems. You’ll play a key role in shaping architecture decisions, improving performance, and ensuring the reliability of high‑traffic distributed systems.

This position is perfect for someone who thrives in a fast‑paced environment, enjoys technical challenges, and values teamwork and impact.

Key Responsibilities:

• Design and develop scalable, modular backend applications and APIs using Java and Spring Boot.
• Own the full development lifecycle - from analysis and coding to deployment and production monitoring.
• Improve system scalability, performance, and reliability.
• Collaborate closely with Product, DevOps, BI, and Marketing teams on cross‑functional initiatives.
• Implement robust logging, monitoring, and alerting (Prometheus, Grafana, Kibana).
• Promote best engineering practices, code quality, and maintain technical documentation.
• Mentor junior developers and contribute to team growth.

Requirements:

• Bachelor’s degree in Computer Science or equivalent practical experience.
• 3+ years of experience in Java development (strong Spring Boot background).
• Proven experience building and maintaining distributed systems and microservices (Docker, Kubernetes).
• Strong understanding of scalability, concurrency, and performance optimization.
• Experience with CI/CD pipelines and automated deployments.
• Ability to monitor and improve application performance using tools such as JFR, JMeter, Micrometer, New Relic, or Datadog.
• Excellent communication and collaboration skills.

Nice to Have:

• Experience with NoSQL (MongoDB, Couchbase) and SQL databases.
• Knowledge of Reactive Programming (Spring WebFlux).
• Familiarity with Prometheus, Grafana, Kibana for monitoring and alerting.

Why Join:

• Be part of a global company building technology that reaches billions of mobile users.
• Work in a collaborative, data‑driven environment using modern technologies.
• Competitive compensation and benefits package.
• Hybrid work model (Warsaw) - flexibility with in‑office collaboration or remote