Senior Java Engineer

DOU Polska; Wrocław; Hybrid; PLN 240,000 - 360,000; Full time

Benefits offered by this job

Flexible working hours

Remote/Hybrid work

Collaborative team environment

Company social events

Annual corporate parties

Comprehensive medical insurance

Education allowances

English language courses with natives

Internal knowledge-sharing sessions

Job summary

DOU Polska is seeking a Software Engineer to join a cloud-native, real-time advertising platform. Lead backend development for low-latency services and collaborate with a team of engineers to scale the system for millions of users.

You will work on distributed architectures, performance optimizations, and end-to-end testing while contributing to CI/CD improvements and technical documentation.

Qualifications

• 4+ years of experience building large scale and low latency distributed systems.
• 7+ years of Java backend development experience.
• Strong understanding of algorithms, data structures, and real-time programming.

Responsibilities

• Develop and maintain complex backend services.
• Write unit, integration, and end-to-end tests.
• Maintain and extend existing services to meet new requirements.
• Participate in code reviews and contribute to technical discussions.
• Help maintain technical documentation.
• Assist in improving CI/CD pipelines.
• Contribute to best practices within the development team.

Skills

Java backend

Distributed systems

Algorithms & data structures

Performance optimization

Multi-threading

Cloud services (AWS/GCP)

English (B2+)

Job description

About The Role

Are you ready to take your Java expertise to the next level? Join our team to work with a highly scalable, highly available, real-time advertising platform that serves millions of users worldwide and handles massive real-time data at scale. We are hiring a Software Engineer to be a vital part of this mission. If you bring extensive experience building complex systems, love great technology at scale, jumping in, and figuring things out in any system, this role is for you! Working in a modern, cloud-native environment, you'll collaborate with a team of top engineers to develop low-latency, distributed systems capable of handling millions of QPS. This is an opportunity to combine innovation, performance engineering, and large-scale impact - while shaping the future of digital entertainment technology.

About The Project

Our client is a leading streaming service based in the United States. With millions of users worldwide, it's devices provide easy access to free TV, live news, sports, movies, etc. The client has an advertising business and also licenses its hardware and software to other companies.

Who are we looking for?

Skills & Experience

• 4+ years of experience building large scale and low latency distributed systems
• 7+ years of Java backend development experience;
• Solid understanding of algorithms, data structures, performance optimization techniques, object-oriented programming, multi-threading, and real-timeprogramming
• Experience with distributed caching, SQL/NO SQL, and other databases is a plus
• Experience with Big Data and cloud services such as AWS/GCP is a plus
• Experience in advertising domain a big plus
• Self-motivated individual with a high level of accountability and ownership
• Critical thinking and practical decision making
• Can do, results-oriented mindset
• Software development best practices: test-driven development, automated testing;
• Knowledge of distributed systems architecture and service oriented systems;
• English: B2+

Will Be a Plus

• Familiarity with machine learning frameworks (e.g., TensorFlow, PyTorch) and working with large language models (LLMs)

Responsibilities

• Develop and maintain complex backend services
• Write unit, integration, and end-to-end tests;
• Maintain and extend existing services to meet new requirements;
• Participate in code reviews and contribute to technical discussions;
• Help maintain technical documentation;
• Assist in improving CI/CD pipelines;
• Contribute to best practices within the development team.

What we offer

Work

• Flexible working hours;
• Collaborative, friendly team environment;
• Remote/Hybrid work;

Life

• Company social events;
• Annual corporate parties;

Health

• Comprehensive medical insurance;

Education

• Allowances for professional education;
• English language courses with native speakers;
• Internal knowledge-sharing sessions.