Mathieu Berthier
Freelance Data / Analytics Engineer
Ingestion → Transformation → BI → Governance. Your modern data stack, industrialized end-to-end.
Paris & Greater Paris Area
What I offer
Services
8+ years of experience in data engineering, analytics and cloud platforms. dbt and modern data stack expert, I support teams from data collection to data delivery.
Modern Data Stack (End-to-end)
Data ingestion (Airbyte, custom Python connectors), Data Warehouse (BigQuery), transformation (dbt Core & Cloud), BI reporting (Looker Studio, Power BI, Preset). Self-service analytics setup for internal teams.
Industrialization & CI/CD
Environment setup (dev/staging/prod), automated tests, continuous deployment via Cloud Functions & Cloud Scheduler. Naming conventions, deployment bundles and technical documentation.
Data Quality & Governance
Defining data ownership in collaboration with data owners, KPI documentation, data catalog setup, data community management and quality monitoring.
Technologies & tools
My background
Experience
8+ years in data engineering and analytics, complemented by 10+ years of expertise in digital marketing.
Eurofiber France
Analytics Engineer
dbt Cloud transformation layer design on BigQuery, Airbyte ingestion oversight, Power BI dashboards, data governance.
Reliable network data and improved visibility through trusted KPIs.
AXA France
Data Management Specialist
Data governance strategy, mapping and documentation of key data assets via Collibra, Data & AI use case valorization.
Improved quality of legacy data assets and mastery of governance.
Botify
Data Engineer
BigQuery Data Warehouse, dbt Core & Cloud pipelines, Airbyte integration, Looker Studio & Preset dashboards, data quality monitoring.
Business user autonomy, reliable insights and analytics time savings.
Keyrus · La Banque Postale Assurances
Data Engineer
360° view Data Warehouses, Spark pipelines (Scala, PySpark), Dataiku DSS workflows, documentation and best practices.
Reduced marketing data silos and improved data quality.
Solocal Group (Pages Jaunes)
Data Analyst
SEO performance analysis of the Pages Jaunes website (traffic, structure, ranking, engagement). SEO database management on Hadoop, Tableau dashboards, web data scraping & cleaning.
Rapid delivery of KPIs for project managers and support for optimization decisions.
My work
Use Cases
Discover some concrete examples of end-to-end data projects.
End-to-end dbt Industrialization
Complete dbt deployment for a SaaS analytics data team: sources, models, job orchestration, automated tests and documentation. Developer onboarding and local environment setup. Result: reliable data and a team 100% autonomous on the transformation pipeline.
Self-Service Analytics Platform
Deployment of a self-service analytics platform (dbt, BigQuery, Superset) to empower business teams. 30 active users in 3 months, faster identification of business opportunities.
Big Data Migration & Modernization
Migration of a legacy system (SAS) to a Big Data stack (Spark Scala, Hadoop). Daily dashboards deployed across 3 business units (finance, marketing, product) and end of manual extractions.
Marketing Big Data Data Warehouse
Marketing DWH built on Hadoop with Dataiku (PySpark & Spark SQL) replacing a SAS system. Consolidated customer data, daily updates and accelerated internal analyses.
Let's work together
Contact
Have a data project in mind? Let's talk. I'm available for freelance missions, consulting or just a conversation.