Data Engineer (Tax Care)

About XTB

XTB is a global company from the financial industry, focusing on online trading of financial instruments. We are the largest FinTech in Poland and a leader in Central and Eastern Europe, and the range of our operations covers several countries, including Asia and South America. At XTB, we focus on the development of our employees, giving them opportunities to gain knowledge and skills in various fields, as well as offering a number of training and development programs. We are a certified Great Place to Work company.

Role Description

We are looking for a Data Engineer to join the Tax Care team within the Customer Care program. We build and maintain the data flows behind XTB's accounting and tax processes — from the subsidiary ledger and client tax declarations to reporting for the finance organization. You will design scalable data pipelines, take part in our migration to Databricks, help modernize database solutions, and co-create a Python service exposing tax data via REST API and web UI. Our output becomes an accounting entry, so data correctness and reliability are the heart of this role.

Responsibilities

• Designing, building and maintaining data pipelines that feed XTB's accounting and tax systems — using SQL, Python, dbt and Apache Spark / PySpark.
• Migrating the existing data platform to Databricks (lakehouse), including rewriting legacy MS SQL Server stored procedures into Spark / Databricks SQL.
• Building and maintaining a data service — a Python backend exposing data over a REST API, together with its web UI — from data model through API design to deployment.
• Working with raw data and designing methods for its integration into the data platform.
• Developing CI/CD pipelines for data engineering solutions.
• Creating and maintaining Infrastructure as Code solutions.
• Integrating the data platform with other systems and applications.
• Participating in architectural decision-making and defining engineering standards.
• Conducting code reviews, documenting solutions, and sharing knowledge with team members.

What we offer

• Real influence on the development of the company and the product.
• Work in an experienced team that is happy to share its knowledge.
• A clear vision of development thanks to regular feedback and clear career paths.
• Regular team-building meetings.

Benefits

• A training budget for courses and conferences that interest you.
• An extra day off on your birthday.
• An extra day off for parents.
• Equipment tailored to your needs.
• Private medical care and group insurance.
• Access to an e-learning platform for learning English and a benefits platform.
• Access to a wellbeing platform and the opportunity to take advantage of workshops and private therapy sessions.
• Remote work, from the office in Warsaw or from a coworking space in your city.

Requirements

• At least 3 years of experience as a Data Engineer or in a related software engineering role.
• Strong Python — ability to write clean, testable production code, including backend services (FastAPI / Flask or similar) exposing REST APIs.
• Advanced SQL (query optimization on large datasets) and practical experience with T-SQL / MS SQL Server, including reading and reasoning about legacy stored procedures.
• Hands-on experience with Apache Spark (PySpark).
• Experience with dbt — models, tests, macros, layered warehouse design.
• Strong understanding of data warehouse design principles and data modeling.
• Practical knowledge of ETL/ELT processes.
• Experience analyzing existing legacy code with the goal of improving it and migrating it to newer technology.
• Familiarity with data quality, monitoring, and pipeline reliability.
• Experience with workflow orchestration tools (e.g., Airflow, Dagster, or similar).
• Knowledge of CI/CD pipeline building and maintenance principles.
• Understanding of REST standards for system integration.
• Strong analytical problem-solving skills and attention to detail — willingness to work under a hard monthly accounting close deadline.
• Effective communication skills and the ability to collaborate with both engineers and non-technical (finance / accounting) stakeholders.
• Openness to learning and exploring new technologies and methodologies.

Nice to have

• Experience with Databricks or another lakehouse platform (Delta Lake, Unity Catalog).
• Experience with Snowflake (our current analytical platform during the migration period).
• Front-end basics — ability to build a simple web UI on top of your own API (React, Streamlit, Dash or similar).
• Experience with SSIS and SQL Server Agent (maintained by another team — useful context, not a daily duty).
• Experience in the financial / accounting / tax domain, or with reconciliation-heavy data.
• Understanding of gRPC for internal system integration.
• Experience with Kafka, Pub/Sub, or other event streaming systems.
• Experience building near-real-time / real-time pipelines.
• Experience working with Infrastructure-as-Code tools.
• Understanding of CDC (Change Data Capture) and data integration from transactional systems.