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Wally HormiWH

Wally Hormi

Data Engineer | Databricks | PySpark | Cloud

€500/day
Paris, FR
3-7 years

Average response time: 1 hour

Freelancer profile translated to English.
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About Wally

Data Engineer with 4 years of experience, specializing in production deployment, migration of complex architectures, and automation of high-volume data pipelines.

My expertise allows me to intervene quickly in Cloud environments and ensure business continuity, even in critical contexts or on undocumented legacy architectures.

🎯 KEY EXPERTISE:
• Databricks & Spark Ecosystem: Migration of legacy code (R/Python) to PySpark (Native Databricks), implementation of Medallion architectures (Bronze to Gold), and optimization of Spark SQL queries.
• Industrialization & Batch: Design and production deployment of automated Databricks Workflows (Trigger mode) with complex data flow processing (millions of rows, hundreds of columns).
• Pipelines & Modern Data Stack: Development of robust Python scripts, integration of Snowflake data warehouses, and Datamart modeling for BI (Power BI, MicroStrategy).
• DevOps Practices: Versioning, CI/CD, containerization, and deployment security (Azure DevOps, GitLab CI/CD, Docker, Git).

Trilingual (French, English, Spanish), I integrate well into local teams as well as international environments.

Available for technically challenging missions. Let's discuss your needs!
  • French

    Native or bilingual

  • English

    Native or bilingual

  • Spanish

    Conversational

  • Portuguese

    Basic

Can work on-site
Paris (up to 30km)

Experience

  • Direct Assurance
    Data Engineer
    BANKING AND INSURANCE
    October 2023 - Today (2 years and 8 months)
    Paris, France
    Context: Production migration and optimization of the data infrastructure towards a modern, cloud-native, and scalable platform.

    Key achievements:
    • Core Engine & Architecture Migration: Complete migration of legacy R programs to PySpark on a native Databricks environment, with the implementation of a Medallion architecture (Bronze to Gold layers).
    • Batch Industrialization & Automation: Design, development, and production deployment of complex Databricks Workflows to automate batch ingestion (Trigger mode), ensuring daily data delivery before the start of the business day.
    • Handling Complex Volumes: Processing and optimization of data pipelines handling several million rows and hundreds of columns to feed critical company Datamarts.
    • Data & BI Reporting: Creation and maintenance of secure and efficient connections between the Databricks environment and Power BI dashboards to enable Data Analysts to generate business insights.
    • DevOps & Git Practices: Management of the Git environment for script versioning, technical collaboration, and deployment security under Azure DevOps.
    Technical environment: Databricks, PySpark, Python, Spark SQL, Azure DevOps, Git, R.
    PySpark Databricks Python Azure DevOps ETL
  • Franprix
    Data Engineer
    RETAIL (LARGE RETAILERS)
    March 2023 - October 2023 (7 months)
    Paris, France
    Context: Strategic mission to take over technical operations and ensure business continuity. Took lead autonomously on a critical data scope following the sudden departure of the previous team. Stabilized the existing architecture and provided technical leadership for a major Proof of Concept (POC) between DataGalaxy and Franprix.

    Key achievements:
    • Ownership & Autonomy: Ultra-fast skill acquisition on a complex, undocumented architecture. Comprehensive audit, security, and operational maintenance of the overall infrastructure.
    • Pipelines & Automation: Design and implementation of robust Python scripts connected to Snowflake to generate functional reports and automate the daily email delivery of results to collaborators.
    • Governance & Cataloging: Complete documentation of existing Python code and cataloging of tables, key performance indicators (KPIs), and MicroStrategy cubes to structure the POC.

    Technical environment: Snowflake, Python, SQL, Docker, GitLab CI/CD, DataGalaxy, MicroStrategy.
    Python Snowflake Gitlab CI Bash SQL
  • Stellantis
    Data Engineer / Python Developer (Stellantis/Google)
    AUTOMOBILE
    April 2022 - December 2022 (8 months)
    Paris, France
    Context: Strategic international migration of 1,400 markets (one of the largest global migrations at the time) for GDPR compliance of digital tracking frameworks to GA4 and GTM.

    Key achievements:
    • Automation & OOP Programming: Design and development of complex Python scripts in Object-Oriented Programming (OOP) combined with Selenium to programmatically recreate and migrate GA4 properties via dedicated Google APIs.
    • GTM Container Migration & Update: Automation of mass migration, creation, and updates of digital data containers on the GTM tool for all international properties and accounts (from JSON configuration files).

    • Cross-Platform Ingestion & Orchestration: Interconnection with Adobe Analytics (via R) and design of Dataiku flows/scenarios to feed and structure target databases (BigQuery) on Google Cloud Platform (GCP).

    Technical environment: Python, Google Cloud Platform (GCP), BigQuery, Dataiku, Selenium, R, Git.
    Google Cloud Platform (GCP) Python Selenium Git Big Query

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Education

  • Double Master's degree
    University of Versailles
    2021
    Double Master's degree
  • Academy Accreditation - Databricks Lakehouse Fundamentals
    Academy Accreditation - Databricks Lakehouse Fundamentals

Skill set

Categories