You're seeing this page as if you were . The main menu is still yours, though. Exit from immersion
Lucas DienisLD

Lucas Dienis

Lead Data Engineer

€835/day
Paris, FR
8-15 years

Average response time: 1 hour

About Lucas

Senior Data Engineer with 10+ years of experience designing and scaling data platforms/architectures in high demand, regulated, international environments (finance, retail, public sector).

I specialize in building robust, production-grade data systems using Databricks and AWS, with a strong focus on performance optimization, developer experience, and platform reliability at scale.

Currently working at Decathlon, I support a data platform used by 3,500+ users (Data Engineers, Analysts, Data Scientists), where I focus on:
  • Platform administration, development & FinOps.
  • Integrating latest Databricks features at scale.
  • Developers tooling & support & standardization.
  • Large-scale data pipeline architecture.

I enjoy bridging the gap between complex data engineering challenges and significant business impacts.

Core skills: Databricks, Spark, AWS, Data Architecture, Performance Optimization
  • French

    Native or bilingual

  • English

    Fluent

Remote only
Primarily works remotely

Experience

  • Decathlon
    Lead Data Engineer
    RETAIL (LARGE RETAILERS)
    January 2023 - Today (3 years and 6 months)
    Paris, France
    Operating as a Lead Data Engineer of a team of 6 Data Engineers within the central Data Platform team, supporting and scaling a Databricks-based ecosystem on AWS used by 3,500+ data professionals.

    • Provide advanced support to Data Engineers, BI Engineers, and Data Scientists (debugging, performance optimization, architecture guidance).
    • Contributed to the design, governance, and reliability of the data platform.
    • Designed and rolled out reusable project templates (Spark, dbt, Airflow, AWS Lambda, EKS) using Cookiecutter, Cruft, Poetry, GitHub Actions, and SonarCloud, enabling standardized and industrialized data development across teams.
    • Improved Databricks infrastructure standardization using Terraform at scale through Hashicorp Entreprise, improving reproducibility, governance and evolution of platform resources.
    • Led the technical migration from AWS Glue to Databricks Unity Catalog, improving data governance, security, and cross-team data accessibility.
    • Implemented platform monitoring, alerting, and FinOps practices to perfect usage and control costs.

    Technical Stack: Databricks, AWS, Apache Spark, dbt, Apache Airflow, AWS Glue, Unity Catalog, Spark Declarative Pipelines, Lakeflow Jobs, AWS EKS, AWS Lambda, Github Actions, Data Contracts.
    Databricks Amazon Web Services Spark Terraform GitHub
  • Autorité des marchés financiers (AMF) – France
    Senior Data Engineer
    BANKING AND INSURANCE
    July 2021 - January 2023 (1 year and 6 months)
    Paris, France
    Joined the cross-functional DataFab team within the Data & Market Surveillance Department, offering technical ability to support data analysts and data preparation workflows.

    • Improved the computation time of a cumulative hypergeometric distribution using Apache Spark (Scala) from 7h to 45min by forking the class HypergeometricDistribution from Apache Commons Math, significantly improving performance of the pipeline.
    • Reduced daily data ingestion time into HBase via Phoenix from 6 hours to 1 hour through performance tuning and process optimization.
    • Integrated analyst-developed market surveillance and alerting tools into a unified software framework to enhance maintainability and scalability, including advanced analytics functions (machine learning models), enabling easier adoption by analyst teams.
    • Designed and implemented data pipelines for publishing open datasets to Data.gouv, ensuring compliance with open data standards.
    • Defined data architecture for integrating annual financial reports of French companies into the AMF data platform.

    Technical Stack: Apache Spark, Apache Hive, Hadoop ecosystem, Python, Scala, Java
    Hive Spark Python Scala Java
  • European Security Market Authority (ESMA)
    Big Data Engineer
    BANKING AND INSURANCE
    April 2020 - June 2021 (1 year and 2 months)
    Paris, France
    Provided consulting and optimization ability for data processing workflows related to European banking regulations within the Supervision & Data Analytics Systems team. Operated in an international environment with English as the primary working language.

    • Designed and implemented data ingestion and transformation pipelines to convert XML regulatory files into structured CSV formats for EMIR, SFTR, and SECR (European Union financial regulations).
    • Defined deployment methodologies and built automated CI/CD pipelines for data processing workflows.
    • Developed, supported and monitored automated data pipelines using Talend, MySQL, and TIBCO Spotfire.
    • Built a scalable XML-to-CSV mapping framework in Java using Altova MapForce, standardizing transformation logic across regulatory datasets.
    • Optimized processing of a 19TB Oracle Database table via partitioning, indexing, and stored procedures, and reduced query latency by implementing caching strategies in TIBCO Data Virtualization.
    • Improved performance and reliability of recurring analytical scripts used by ESMA analysts, implementing monitoring and optimization best practices.

    Technical Stack: Oracle Database, Talend, Altova MapForce, TIBCO Spotfire, TIBCO Data Virtualization, Python, Java, SQL.
    Python Java SQL Git Oracle

Recommendations

Be the first to recommend Lucas

Help this freelancer shine by sharing your experience working together.

These freelancer profiles also match your criteria

AgathaA

Agatha Frydrych

Backend Java Software Engineer

4.7

(3)

2

BaptisteB

Baptiste Duhen

Fullstack developer

4.6

(4)

5

AmedA

Amed Hamou

Senior Lead Developer

4

(2)

7

AudreyA

Audrey Champion

Web developer

4.3

(3)

4

Education

  • Diplôme d'ingénieur, Technologies de l'information
    IMT NORD EUROPE
    2016
    Diplôme d'ingénieur, Technologies de l'information
  • Diplôme d'ingénieur, Technologies de l'information
    Санкт-Петербургский государственный университет
    2015
    Diplôme d'ingénieur, Technologies de l'information

Skill set

Categories