# (Senior) Java Developer - Freelance

> Netguru · Poland (Remote) · Contract · Posted 2026-05-11

**Workplace:** remote

**Department:** NTG Freelancer

## Description

Netguru is a trusted partner in digital commerce. The company helps leading brands modernize B2B solutions, marketplaces, and retail ecosystems. Since 2008, it has empowered businesses with cutting-edge technology, AI-powered personalization, and world-class engineering and design teams. A certified B Corporation®, Netguru is trusted by major brands including IKEA, VW, OLX, Delivery Hero, Żabka, Wolt, Careem, and Vinted.  
  
**  
  
Position: Senior Backend Engineer**

**Contract: B2B – Remote (EU Only)**

**Rate: up to 30 EUR/hour + 20 paid vacation days**

**Language: English C1  
  
  
Responsibilities**

-   Design and build scalable backend systems for processing large volumes of spare parts data
-   Develop and maintain robust, high-performance APIs for data integration and access
-   Build, optimize, and maintain ETL pipelines for data ingestion and transformation
-   Process and manage large datasets in distributed environments
-   Optimize system performance, latency, and throughput across backend services
-   Improve database performance through indexing, schema design, and query optimization
-   Collaborate with product managers, designers, and engineering teams to deliver scalable solutions
-   Work closely with stakeholders to define and implement data-driven functionalities
-   Ensure high standards of security, reliability, scalability, and maintainability
-   Mentor and support other engineers as part of a senior-level engineering role
-   Stay up to date with modern backend technologies, architecture patterns, and engineering best practices

## Requirements

-   **Tech stack & requirements**

-   Strong commercial experience with JVM-based languages such as Java, Scala, or Kotlin
-   Solid experience with relational databases, including PostgreSQL and MySQL
-   Experience working with NoSQL databases, preferably MongoDB
-   Hands-on experience processing and managing large datasets
-   Strong knowledge of scalable API design and backend architecture principles
-   Experience designing distributed and high-performance systems
-   Practical experience building ETL pipelines using standard data processing tools
-   Experience with cloud platforms such as AWS, GCP, or Azure
-   Strong understanding of performance optimization and low-latency systems
-   Experience with database optimization, including indexing, schema design, and performance tuning
-   Strong problem-solving and communication skills
-   Senior-level mindset with the ability to mentor and support engineering teams
-   **English at C1 level**
-   **Must be based in the European Union**

## Benefits

### **In return, we offer:**

-   100% remote, flexible work;
-   work with an experienced team of developers and continuous development of your hard and soft skills;
-   dev-friendly processes such as Continuous Integration, Continuous Delivery, Code Review and bug bashes;
-   long-term collaboration on challenging products (FinTech, B2B software, E-commerce and more).

**What will happen next?**

-   We would like to know you better, so we will invite you for a meeting with our recruiter.
-   Next, you'll be asked to solve the task or invited to an interview and pair programming with one of our iOS Developers.

  

Looking for a full-time job? Check out our [Career Page](https://www.netguru.com/career) and find out more about our open recruitment processes.

If you need any disability-related adaptation at any step of the recruitment process – simply let the recruiter know! We'd be happy to help.

## Apply

[Apply at Netguru](https://apply.workable.com/netguru/j/CD16AE9033/apply)

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