Bartosz Konieczny is a freelance data engineer enthusiast who has been coding for 15+ years. He has held various senior hands-on positions that helped him work on many data engineering problems in batch and stream processing, such as sessionization, data ingestion, data cleansing, ordered data processing, or data migration. He enjoys solving data challenges with public cloud services and Open Source technologies, especially Apache Spark, Apache Kafka, Apache Airflow, and Delta Lake. Beyond that, readers can read his data engineering blog posts at waitingforcode.com each month.