Database Engineer (PostgreSQL)

I’m helping StaffInIT find a top candidate to join their team full-time for the role of Database Engineer (PostgreSQL).

You'll own critical banking data projects, optimizing terabyte-scale systems in a new competency hub.

Compensation:

PLN 100 - 150/hour.

Location:

Hybrid: Łucka 15, 00-842 Warszawa, Poland.

Mission of StaffInIT:

"Our mission: to connect talent. empower businesses. We work with clients across industries, helping them build teams that make a difference, and support professionals in finding roles where they can thrive. At our core, we combine deep recruitment expertise with a human-centred approach—ensuring that each placement aligns skills, culture and ambition."

What makes you a strong candidate:

• You are proficient in SQL, PostgreSQL.
• Polish - Fully fluent.
• English - Fully fluent.

Responsibilities and more:

• Strong knowledge of SQL or PL/pgSQL (PostgreSQL) and the ability to use it when working with large-scale databases.
• Experience handling datasets with billions of records and terabytes of data, ensuring efficient processing.
• Ability to optimize queries and long-running processes, including those lasting several hours.
• Ability to analyze query execution plans and quickly identify bottlenecks.
• Experience working with stored procedures and using them effectively.
• Proficiency in Python for maintaining and developing business logic.
• Ability to troubleshoot performance issues at the L2 level.
• Strong analytical skills to work with data and issues from multiple sources.
• Ability to analyze system logs and use tools like *pg_stat_statements* to identify blocking processes and bottlenecks.
• Knowledge of data partitioning (especially by date) to optimize queries on terabyte-scale tables.
• Experience working at the L2 level, including troubleshooting and maintaining production environments.
• Upper-intermediate to advanced English proficiency (B2/C1).

Nice to Have:

• Experience with BigQuery, Airflow, and databases (DB).
• Familiarity with cloud-based database environments (AWS, Azure).

What We Offer:

• Work on projects based on PostgreSQL, data warehouses, and systems processing very large volumes of data.
• Opportunity to join a newly established 5–6 person competency hub in Poland, which will eventually take full ownership of the project from a team in Spain.
• Contribution to a critical banking application responsible for revenue management and stock reconciliation, within a unique multi-cloud environment (AWS and GCP).
• Growth opportunities in Data Warehousing (DWH), data integration, and database solutions.
• Advanced PostgreSQL engine management, including MVCC mechanisms (Xmin/Xmax), Vacuum processes, and custom indexing strategies such as BRIN.
• Clear career path and professional development support at the L2 level.
• Exposure to challenging and innovative work in Data and analytics.
• Benefits package: private healthcare, insurance, and sports card.
• Work with the latest technologies and market trends.
• Competitive salary.
• A great and supportive work atmosphere.