(Senior) Java Developer - Freelance

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 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

• 100% remote, flexible work
• Work with an experienced team of developers and continuous development of 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.

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.