Senior Data Engineer

We've been building digital products for over 10 years, with a strong focus on Blockchain-based applications. At 4soft, people come first — it's our team of passionate technologists that enables us to work with international clients and deliver innovative solutions. We believe in transparency, effective teamwork, and achieving real business outcomes for those we serve.
Want to work on data infrastructure that powers cutting-edge crypto intelligence products? Growth and a great team culture matter to you? 4soft is the perfect place to find both.
Join our client's data engineering team - a global leader in blockchain analytics - and help drive the technical direction of a data platform that sits at the heart of everything they do. As a Senior Engineer, you'll architect systems that process massive blockchain and off-chain datasets, mentor engineers around you, and shape decisions that matter. If you're genuinely excited about large-scale distributed systems and want real ownership over critical infrastructure, this is your place.

Tech environment: Scala, Spark, Databricks, AWS, Airflow, Kubernetes, Terraform, Functional Programming

As a Senior Data Engineer, you will be responsible for:
• Architecting, designing, and implementing large-scale distributed data systems and pipelines that serve as the backbone of all  products
• Driving technical decision-making across batch and streaming data solutions, balancing scalability, performance, and long-term maintainability
• Exploring and integrating new technologies - data orchestration tools, cloud-native solutions - to continuously optimise performance and scalability
• Contributing to platform-wide initiatives that improve reliability, observability, and cost efficiency across the entire data infrastructure
• Taking shared ownership of data systems from design through deployment and ongoing support, ensuring they meet the growing demands of blockchain analysis
• Collaborating with engineers, product managers, data scientists, and intelligence analysts to build customer-focused features and scalable architectures
• Mentoring engineers, performing thoughtful peer reviews, and championing best practices that raise the quality bar across the team

What we expect from you:
• Proven ability to design, build, and maintain distributed data systems in a cloud-based environment
• Hands-on experience with big data frameworks such as Spark or Databricks
• Solid knowledge of cloud infrastructure - AWS, GCP, or Azure
• Strong software engineering fundamentals: you write clean, testable, and efficient code, think about maintainability, and know what it means to build something others will depend on for years
• The judgement to navigate trade-offs between scalability, performance, resilience, and cost - and to communicate those decisions clearly to technical and non-technical stakeholders
• Experience or genuine interest in functional programming, data modelling, workflow orchestration, or AI-driven tools
• A learning mindset, visible in how you talk about your work: what you've built recently, what you'd do differently, and what drew you to data engineering in the first place
• English proficiency at C1 level or above (for international client collaboration)
• Polish language skills at B2 level or above (for smooth communication with the team)

Great if you also bring:
• Experience in stream processing frameworks and event‑driven architecture
• Hands‑on experience with Infrastructure as Code (Terraform, CloudFormation)
• Experience working in containerised environments (Docker, Kubernetes)
• Interest in crypto and blockchain technologies

What helps us stay balanced:
• Grow your skills and hobbies with us -  make use of a dedicated training and wellbeing budget
• Work from home or the office - your choice, up to 100% remote
• Access to specialists whenever you need them via our LuxMed healthcare package
• If the gym is your second home, activate a Multisport card with us
• Looking for a long-term home? You're in the right place — stable collaboration, no dress code, no heavy atmosphere
• Our team knows how to have fun: board games, city outings, go-kart races, laser tag, great food on team retreats -  we take integration seriously (in the best way :)