Data Engineer

OpportuLand; Kraków; Hybrid; PLN 180,000 - 260,000; Full time

Job summary

OpportuLand is hiring a Mid Data Engineer in Kraków, Poland to own the company data lake—the single source of truth for millions of financial events daily across a large user base.

You will design lakehouse layers (bronze/silver/gold), manage CDC streaming (Kafka/Debezium), and optimize storage and query performance on Snowflake, Databricks, or BigQuery, while ensuring regulatory compliance and data governance.

Qualifications

• 3 years of hands-on experience delivering data lakehouse architectures.
• Experience with bronze/silver/gold layering and schema evolution.
• Experience with CDC streaming (Kafka/Debezium) and late/duplicate events.
• Strong SQL and data modeling for TB+ scale.
• Familiarity with Snowflake, Databricks, or BigQuery in production.

Responsibilities

• Own lakehouse architecture and data landings from source systems.
• Design data layout for speed and cost with partitioning and compaction.
• Ensure regulatory retention, immutability, and GDPR deletion.
• Governance: catalogs, lineage, access controls, and masking.
• Monitor ingestion health and cloud storage/compute spend.

Skills

SQL proficiency

Data modeling

Python

Streaming data (CDC)

Cloud data warehousing

Tools

Snowflake

Databricks

BigQuery

Trino

Athena

Kafka

Debezium

Iceberg

Delta Lake

Hudi

Airflow

Dagster

S3

GCS

Job description

## Data EngineerWe are looking for a Mid Data Engineer in Kraków, Poland who will own the company data lake — the system of record for millions of financial events a day (bets, wallet movements, live odds) across 12M+ active users. You decide how that data lands, is stored, retained, and governed on S3 + Snowflake/Databricks, so analytics, finance, and regulators all see accurate, reconciled data with zero drift from source.Domain: Regulated iGaming / wallet & ledger data. Audit-heavy: regulators, finance and analytics all consume the same tables. Millions of financial events per day, terabyte-plus scale.What you'll be doing:Own the lakehouse architecture: bronze/silver/gold layers, Iceberg/Delta tables, schema evolution.Land operational data via CDC streaming (Kafka, Debezium), handling late and duplicate events.Design data layout for speed and cost: partitioning, compaction, file sizing, query performance on Trino/Athena/Snowflake.Own retention and archival: storage tiering, regulatory retention, immutability, GDPR deletion.Guarantee correctness: freshness SLAs, drift detection, reconciliation against the source wallet and ledger systems.Own governance: catalog and lineage, row/column access control, PII masking, encryption, audit trails.Monitor ingestion health, data anomalies, and cloud storage/compute spend.Must-have:3 years' experience in hands-on delivery within that architecture — pipelines, ingestion, models, monitoringLakehouse architecture — bronze/silver/gold layering, an open table format (Iceberg, Delta, or Hudi), schema evolution.Data layout & query optimization at TB+ scale — partitioning, compaction, file sizing, query performance on Trino/Athena/Snowflake.Cloud lakehouse/DWH in production — Snowflake, Databricks, or BigQuery.CDC & streaming ingestion — Kafka + Debezium or equivalent; late, duplicate and out-of-order events.Strong SQL and data modeling — enough relational grounding to reason about the OLTP systems you capture from. Critical for financial ledgers.Correctness — freshness SLAs, drift detection, reconciliation against source wallet/ledger systems.Governance — catalogs, lineage, row/column access control, PII masking, retention, GDPR deletion.Cloud object storage — S3 or GCS, plus storage tiering and archival.Python and an orchestrator — Airflow or Dagster, as tools.Location & work model:Kraków, Poland. Hybrid — 2 days per week from the office.