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Illiyas MarecarIM

Illiyas Marecar

Data Engineer

€480/day
Paris, FR
8-15 years

Average response time: 1 hour

Freelancer profile translated to English.
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About Illiyas

Hello 👋

I am Illiyas,Data Expert/ **Data Engineer**.

9 years ago, I built my first data pipeline.

Since then, I've spent nearly a decade building data systems
that process millions of events per day.

I have migrated entire architectures without downtime.
I have debugged Airflow DAGs that were in an infinite loop at 3 AM.
I have seen Kafka partition in any way possible.
I have optimized Spark jobs that took 6 hours to run, reducing them to 20 minutes.

In 2017, I dove deep into data engineering.

Not by chance. By conviction.

Because I understood that the companies that would dominate
the next decade would be those capable of transforming
their data into intelligent systems.

Not those that store it. Those that EXPLOIT it.

Today, I no longer code just for the sake of coding.

I build data architectures that:
→ Scale from 1K to several million events/day without redesign
→ Run in production without waking up the team at night
→ Cost 40% less thanks to cloud optimization

I transform your data infrastructures into strategic assets.

My concrete achievements:

- Snowflake → AWS/Databricks Lakehouse Migration (RATP): -30% costs, +50% performance, migration of 100+ dbt models
- Real-time prediction platform (La Poste): +25% accuracy, -15% logistics costs, several million packages/day
- Scalable Data Mesh Architecture for RATP Group: time-to-market divided by 3
- Regulatory DataLake (Natixis): 0 downtime in production, critical 24/7 environment

My expertise:
- Modern data architecture (Data Lakehouse, Data Mesh, Lambda Architecture)
- Real-time streaming and distributed batch processing
- Distributed processing (ETL, ELT, ...)
- MLOps and AI in production (deployment, monitoring, CI/CD)
- Microservices and containerization
  • French

    Native or bilingual

  • English

    Fluent

Can work on-site
Paris (up to 50km)

Experience

  • RATP
    Data Architect
    TRANSPORTATION
    June 2023 - Today (3 years)
    Paris, France
    Building the Group Data Platform that centralizes all RATP data projects and allows business teams to access data services in self-service.

    Scaling the platform for adoption by 15+ teams in 18 months.

    Key Achievements:
    → DataMesh Architecture enabling 50+ Data Engineers, Ops, and Business users to access data in a decentralized and governed manner
    → Implementation of a batch and real-time ingestion pipeline processing millions of events/day (Spark, Kafka, S3)
    → Deployment of microservices with automated CI/CD (GitLab)
    → Reduction of data project deployment times by 40% through automation
    → Training and upskilling of 20+ Data Engineers on the Spark ecosystem and architecture best practices

    Technical Stack:AWS, Spark, Scala, Databricks, S3, Data Mesh Architecture, GitLab CI/CD, Terraform
    AWS Snowflake DBT Scala Databricks
  • Geopost
    Lead Data Engineer
    LOGISTICS AND SUPPLY CHAIN
    April 2021 - June 2023 (2 years and 2 months)
    Paris, France
    Developing from scratch a real-time platform for detecting delayed packages based on Machine Learning, enabling anticipation of logistical issues before they impact customers.

    Result:35% reduction in delivery delays through predictive detection.

    Technical Achievements:
    → Architecture and deployment of a real-time ingestion pipeline processing 2M+ events/day (Spark Streaming, Kafka, Airflow)
    → Full platform containerization on Kubernetes
    → Deployment of ML models with real-time monitoring and alerting
    → End-to-end fully automated CI/CD (GitLab, GitLabHQ)
    → Optimization of Spark jobs: 60% reduction in execution time and 40% in cloud costs

    Stack:Spark • Kafka • Airflow • Cassandra • S3 • Kubernetes • Docker • GitLab • JupyterHub • Scala • Python • Java

    Business Impact:Anticipation of delays • Improvement of customer satisfaction • Reduction of
    Docker Kubernetes Python Spark Airflow
  • Artifeel
    Data Engineer
    PUBLIC SAFETY
    January 2021 - March 2021 (2 months)
    Paris, France
    Designing and implementing a Cloud/Azure architecture.

    Project:Deployment of an Azure architecture for detecting abnormal behavior in time series using Machine Learning models.

    Achievements:
    - Setting up a data integration pipeline (development and scheduling via Azure Functions),
    - Securing access and data (Azure Key Vault),
    - Preparing the development environment for building Machine Learning models (Azure Machine Learning),
    - Monitoring the actual daily consumption of resources used.

    Result:Installation of a cloud architecture.

    Technical Stack:MS Azure (ADLS Gen2, Functions, Key Vault, Machine Learning).
    MS Azure Python Cloud Integration Cloud Administration Infrastructure as Code

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Education

  • Degree in Aeronautical and Space Systems Engineering
    Institut Polytechnique des Sciences Avancées
    2010
  • Specialization Certificate in Massive Data Processing
    Conservatoire National des Arts et Métiers
    2017

Certifications

  • Microsoft Azure: Fundamentals
    Microsoft
    2023
  • GCP: Associate Cloud Engineer
    Google Cloud Platform
    2023

Skill set

Categories