Mazen S.

Junior Data Engineer | PySpark, Databricks, Delta Lake & AWS Lakehouse

I build production-grade Lakehouse pipelines that turn messy, unreliable data into clean, trustworthy datasets using PySpark, Databricks, Delta Lake, and AWS.

What I bring:

* End-to-end ETL/ELT pipelines with PySpark, Spark SQL, Delta Lake, and Unity Catalog

* Medallion Architecture (Bronze → Silver → Gold) with data-quality validation

* Dimensional data modeling using Star and Galaxy Schemas

* AWS data ingestion and storage with S3, IAM, and Glue

* Python and SQL for transformation, validation, and data processing

* Version-controlled pipelines using Git/GitHub

Flagship Project — Bayt El-Cash Lakehouse:

I independently designed and built a Medallion Lakehouse pipeline processing 35M+ transaction records across 11 years and 15 branches. Around 40% of the migrated records contained missing or inconsistent data, including balances, phone formats, and dates. I built a stateful ledger-reconstruction engine using PySpark Window Functions and deterministic business rules to recover missing values, then modeled the cleaned data into a Galaxy Schema with automated reconciliation checks.

I’m early in my freelance journey and building my track record, so I offer focused communication, competitive rates, and an honest approach to what I can deliver.

Tools: PySpark, Databricks, Delta Lake, Spark, AWS, SQL/PostgreSQL, Python, Unity Catalog, Git/GitHub