Open to opportunities

Joseph Zemek

@josephzemek

I build real-time, cloud-native data platforms for fintech and healthcare.

I've built high-impact data platforms at Headway and Robinhood, from healthcare claims and provider credentialing systems to real-time trading, portfolio analytics, and financial ledger platforms. My work uses Databricks, Kafka, Spark, Snowflake, dbt, Airflow, Python, and AWS to turn complex operational data into trusted products.

At Headway, I reduced large-scale healthcare ETL execution time by more than 60% and built claims pipelines processing millions of records daily. At Robinhood, I improved market-data analytics query performance by more than 70%, reduced portfolio update latency by over 60%, and supported 99.9% production pipeline availability through resilient, governed data engineering.

Experience

Work history, roles, and key accomplishments

Current

Senior Data Engineer

Current

Headway

Aug 2021 - Present (5 years)

Spearheaded the architecture of Headway's Insurance Claims & Revenue Cycle platform, designing Python, PySpark, SQL, Apache Airflow, Snowflake, and dbt pipelines that transformed complex payer transactions into trusted healthcare datasets. Engineered scalable CDC and incremental ELT frameworks using Airflow, PySpark, AWS S3, and Snowflake Streams, processing millions of insurance claims daily whil

Python PySpark SQL Airflow Snowflake DBT S3 Snowflake Pipelines CDC ELT Data Quality HIPAA Databricks Delta Lake Debezium Fivetran Terraform GitHub Actions Cloudwatch RBAC AWS KMS

Senior Data Engineer

Robinhood

Jul 2017 - Jul 2021 (4 years)

Architected Robinhood's Real-Time Trading & Market Data Platform using Apache Kafka, Spark Structured Streaming, Databricks, PySpark, Delta Lake, Snowflake, dbt, and Airflow, enabling scalable processing of high-volume market events that powered order execution, portfolio balances, buying power, and trading analytics with sub-minute data freshness. Built Robinhood's Portfolio Analytics Platform, d

Kafka Spark Structured Streaming Databricks PySpark Delta Lake Snowflake DBT Airflow Debezium Terraform GitHub Actions Cloudwatch RBAC Data Quality

Data Engineer

UnitedHealth Group

Jan 2014 - Jul 2017 (3 years 6 months)

Developed ETL workflows for UnitedHealth's Enterprise Healthcare Claims Data Warehouse using Informatica PowerCenter, Oracle, PL/SQL, Python, and Unix Shell, integrating millions of monthly claims, member, provider, and payment records into trusted datasets supporting claims adjudication, provider analytics, finance, and regulatory reporting. Streamlined healthcare claims processing by implementin