A Lightweight Big Data Stack for Python Engineers

The author is excited to share their thoughts and experiences in the field of data engineering, having worked with Python-based technologies like Flask, Apache Airflow, and DuckDB. Data engineering is a critical discipline that focuses on building and maintaining the architecture, pipelines, and systems necessary for collecting, storing, and processing large volumes of data. A data engineer is responsible for ensuring that data is collected, cleaned, structured, and made available in a timely manner, requiring a strong understanding of databases, distributed systems, scripting, and workflow orchestration tools. ETL (Extract, Transform, Load) and ELT (Extract, Load, Transform) pipelines are central tasks in data engineering, with ELT gaining popularity with the rise of cloud-native data warehouses. Data lakes, like IBM Cloud Object Storage, are centralized repositories that store all structured, semi-structured, and unstructured data at scale, supporting schema-on-read and allowing more flexibility for exploration and modeling. The author highlights the importance of tools like Pandas, SQL, Parquet, DuckDB, and PyArrow in data engineering, forming a powerful suite for local and scalable data processing. DuckDB is a better fit than Modin or Vaex for large-scale data processing, particularly in Parquet format, due to its efficiency at processing queries directly on disk without loading the full dataset into memory. The author provides examples of using DuckDB to calculate trip duration, average fare per distance bucket, and vendor-wise earnings from the NYC Yellow Taxi Trip Data dataset. Apache Airflow is used to orchestrate pipelines, allowing engineers to define workflows as Directed Acyclic Graphs (DAGs) using Python, supporting task dependencies, scheduling, retries, logging, and alerting out-of-the-box. Data engineering is a foundation and force multiplier for modern analytics and AI systems, requiring a mix of software engineering, data modeling, and system design skills.