Java Backend Engineer, Dataflow

Loopme; Kraków; On-site; PLN 80,000 - 100,000; Full time

Job summary

A leading advertising technology firm in Kraków is looking for a Java Backend Engineer to develop a high-load ad-serving system that can handle over 2 million requests per second. This role includes optimizing performance using Java, SQL, and Kafka, while working in an Agile environment. Perks include a competitive salary, flexible working schedule, and the option for a workation month.

Benefits

Competitive compensation package

Flexible working schedule and hybrid work

Annual performance bonus

One month of workation

Qualifications

• 3+ years of engineering experience.
• Strong understanding of concurrency in Java.
• Experience with modern SQL-based databases.

Responsibilities

• Develop features and optimize performance for Java ad-serving applications.
• Implement data processing streams and gather statistical data.
• Automate report generation and prepare data for other departments.

Skills

Java

Microservice architecture

Concurrency

SQL

Kafka

Tools

Kubernetes

Clickhouse

Job description

Kraków, Lesser Poland Voivodeship, Poland | Marketing and Advertising | Full-time

Description

Are you interested in working with cutting‑edge technologies and developing high‑performance applications capable of handling over 2 million data queries per second? If so, we have the perfect job for you at LoopMe! We are a team of skilled engineers who develop and maintain real‑time bidding platforms for global advertisers. As part of our team, you will work alongside other talented engineers on a daily basis, using technologies such as Java, Postgres, Clickhouse, Kafka, and others to scale performance, optimize cloud infrastructure, and create innovative features for our various product lines. At LoopMe, we follow Agile methodology to deliver features rapidly to the market. Join us and be a part of our mission to push the boundaries of what is possible in the advertising industry!

We are looking for a Java Backend Engineer to help build out our high‑load ad serving system, capable of handling over 2M requests/second under 50ms response time.

What you'll be doing:

• Developing features and optimise performance for a high‑load Java ad‑serving application
• Implementing data processing streams and gather statistical data
• Preparing data for other departments and automate report generation

You'll have:

• 3+ years of engineering experience
• Understanding of microservice architecture
• Proficient in Java with a strong understanding of concurrency.
• trong knowledge of SQL and experience with modern RDBMS
• Experience with Kafka

Nice-to-have:

• Experience with Kubernetes
• Experience with columnar DB (Clickhouse, Vertica, etc)
• Be a self‑motivated, reliable and flexible team player
• Competitive compensation package
• Flexible working schedule and the hybrid type of work
• Annual performance bonus
• One month of workation (you can work from any part of the world for one month)

To all recruitment agencies: LoopMe does not accept agency resumes. Please do not forward resumes to our jobs career page, LoopMe employees or any other company location. LoopMe is not responsible for any fees related to unsolicited resumes.