(Senior) Java Developer – Freelance

Poland (Remote)

Posted 2 weeks ago

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 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

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 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.