
Florent Lefort
Verified Expert in Engineering
Data Scientist and Developer
Paris, France
Toptal member since May 5, 2026
Florent is an analytics engineer with 10 years of experience in data. He designs and industrializes the data layer that analytics and operational teams rely on: dimensional models, ELT pipelines, and curated data marts built with SQL, dbt, and BigQuery. Florent has delivered for clients in retail, banking, pharma, media, and the public sector. His data science background makes him unusually good at anticipating what downstream consumers actually need from a model.
Portfolio
Experience
- SQL - 10 years
- Python - 8 years
- Data Analysis - 8 years
- Data Engineering - 4 years
- Qlik Sense - 2 years
- Data Build Tool (dbt) - 2 years
- Microsoft Power BI - 2 years
- Google Cloud Platform (GCP) - 2 years
Preferred Environment
SQL, Python, Microsoft Power BI, Qlik Sense, Google Cloud Platform (GCP), BigQuery, Apache Hive, PySpark, Data Build Tool (dbt), Dataiku
The most amazing...
...project I deployed is a decision-support system for banking advisors—providing instant approve/reject recommendations and cutting transaction processing time.
Work Experience
Analytics Engineer
France Travail
- Designed and delivered a centralized job offers hub by aggregating large-scale data lake sources, including job postings, alerts, applications, and hiring declarations.
- Built automated KPIs and monitoring metrics to track offer distribution activity, new job postings, application volumes, and marketplace attractiveness.
- Developed an interactive analytics dashboard enabling product managers to monitor offer diffusion performance and identify operational anomalies in real time.
- Eliminated complex manual SQL reporting workflows by creating a unified and business-ready data reference used across multiple product teams.
- Collaborated with cross-functional stakeholders to align and interconnect multiple enterprise data hubs across departments.
- Supported business and functional teams in adopting the centralized data platform, improving accessibility and data-driven decision-making.
- Engineered real-time monitoring dashboards for LLM usage and consumption tracking to support the large-scale adoption of generative AI services.
- Aggregated and analyzed LLM operational metrics, including requests per minute, token ingestion, token generation, and associated infrastructure costs.
- Implemented statistical monitoring visualizations and distribution analysis dashboards to detect abnormal AI consumption patterns and prevent cost overruns.
- Built automated deployment pipelines and daily data refresh processes, enabling product managers to proactively manage LLM adoption, usage quotas, and quarterly budget forecasting.
Data Scientist
Groupe BPCE
- Designed and deployed a machine learning decision-support system to automate the validation and rejection recommendation process for high-volume banking operations.
- Built scalable training datasets from relational database systems by consolidating business-critical banking transaction data.
- Engineered predictive features and risk indicators to improve the accuracy and reliability of banking operation classification models.
- Developed explainable AI mechanisms exposing the top contributing factors behind each prediction, increasing advisor trust and decision transparency.
- Defined operational thresholds and scoring rules to prioritize high-risk banking transactions and streamline manual review workflows.
- Created real-time monitoring dashboards and automated alerting systems to detect model drift and ensure long-term prediction reliability in production.
- Delivered a predictive churn model identifying insurance customers at high risk of cancellation up to three months in advance.
- Performed advanced data analysis and feature engineering to uncover weak behavioral signals associated with insurance product attrition.
- Built and productionized machine learning models enabling proactive retention strategies and targeted customer engagement campaigns.
- Enabled insurance advisors to proactively recommend better-suited products to at-risk customers, improving retention effectiveness and reducing revenue loss.
Data Scientist
Valeuriad
- Developed an AI-powered consultant matching engine enabling sales teams to identify the most relevant expert profiles for client RFPs in seconds.
- Built NLP pipelines and embedding-based models to transform unstructured consultant skill profiles into searchable vector representations.
- Implemented similarity scoring algorithms to automatically rank and recommend the best consultant profiles for staffing and mission replacement scenarios.
- Designed interactive 2D clustering visualizations mapping the skill proximity of 150+ consultants, improving visibility into available expertise across the organization.
- Automated profile vectorization and visualization updates to continuously reflect employee onboarding, departures, and evolving skillsets.
Data Scientist
Servier
- Developed deep learning models on 10,000+ knee MRI scans to predict osteoarthritis progression one year in advance for clinical trial patient selection.
- Combined medical imaging, demographic, and clinical patient data to improve prediction accuracy and identify high-progression patient profiles.
- Built machine learning models leveraging structured clinical datasets to complement MRI-based progression predictions.
- Supported Phase III clinical trial strategy by identifying patients with the highest likelihood of disease progression, increasing the probability of demonstrating drug efficacy.
- Transformed MRI data into a high-value decision-making asset for R&D and clinical operations teams involved in osteoarthritis drug development.
- Led large-scale IoT health data initiatives involving 1,500 connected wearable devices collecting real-world sleep and behavioral data.
- Processed and analyzed physiological sleep signals from connected bracelets to identify interpretable sleep behavior patterns and typologies.
- Applied sequence analysis and clustering techniques to classify sleep profiles based on sleep phases, awakenings, and nightly behavioral patterns.
- Correlated wearable device insights with behavioral questionnaire data to uncover actionable findings related to lifestyle habits and sleep quality.
- Demonstrated the feasibility of large-scale connected health programs and established technical expertise in IoT-driven clinical data science for future digital health studies.
Data Analyst
Carrefour
- Built a marketing data mart from raw sales and SGBD data, aggregating performance by product category and enabling structured analysis of advertising impact on revenue.
- Engineered features to isolate promotional effects and model media investment intensity, improving the reliability of advertising attribution.
- Developed a linear explanatory modeling framework to quantify the incremental impact of advertising on sales performance.
- Measured advertising effectiveness, attributing approximately 5% of total sales to media campaigns, representing several million euros in incremental revenue.
- Designed and delivered an interactive dashboard enabling marketing teams to visualize model outputs and analyze campaign performance across channels.
- Enabled scenario-based budget optimization, allowing teams to simulate and optimize media allocation across TV, radio, and other channels to maximize ROI.
Data Analyst
Havas
- Developed a budget allocation optimization tool to maximize advertising reach across multiple media channels (TV, digital, radio, press).
- Designed an interactive simulation interface allowing users to define target audiences, configure media constraints, and model performance based on budget scenarios.
- Implemented scenario-based optimization logic to evaluate and compare multiple media allocation strategies in terms of overall audience exposure.
- Delivered a reporting layer to visualize simulation outputs across structured outputs and performance views for business users.
- Enabled marketing teams to instantly test and select optimal media strategies, significantly reducing the time required for campaign planning and budget allocation decisions.
Experience
Centralized Job Offers Hub & Distribution Activity Dashboard
https://florentlefort.github.io/candidatures.htmlI built the Hub by aggregating and reconciling data from multiple tables (job postings, alerts, applications, and hiring declarations) into a single structured data model. On top of this foundation, I defined and calculated key KPIs such as the number of active postings, newly published offers, and application volumes. I then developed an interactive dashboard with dynamic filters to enable real-time exploration of these metrics and support daily operational monitoring.
I also supported functional users in adopting the solution and participated in cross-team coordination to ensure consistency across interconnected data hubs. The final solution became a shared reference for product managers, significantly reducing time spent on data extraction and enabling real-time detection of anomalies in job distribution activity.
Predictive Model to Automate Banking Transaction Validation
I built the training dataset by extracting and structuring data from the SGBD based on business-defined criteria, and engineered relevant features to improve predictive performance. I then developed a classification model to predict whether each transaction should be validated or rejected, and defined variable-specific thresholds to support decision logic. To ensure transparency, I implemented explainability mechanisms by computing and exposing the top contributing factors for each prediction.
Finally, I designed a monitoring dashboard to track model outputs and detect performance drift over time. The solution was deployed in production and is now used daily by banking advisors, providing instant recommendations with clear explanations, significantly improving trust in the system and supporting faster, more consistent decision-making.
Marketing Mix Modeling and Media Budget Optimization Platform
I built a centralized data mart by aggregating sales data across product categories and store departments from relational databases. I engineered promotional and media investment indicators to isolate the effect of advertising campaigns on sales and developed explainable linear models to quantify the contribution of TV, radio, and promotional activities to revenue generation.
I also created an interactive dashboard that enables stakeholders to visualize model outputs and simulate budget-allocation scenarios across media channels. The solution showed that advertising campaigns generated approximately 5% of total sales, representing several million euros in attributable revenue, and helped marketing teams optimize future campaign ROI.
Education
Master's Degree in Mathematical Engineering (Statistics and Probability)
University of Nantes - France
Certifications
Dataiku Advanced Designer
Dataiku
dbt Fundamentals
dbt Labs
Machine Learning Engineering for Production (MLOps)
Coursera
Deep Learning
Coursera
AI for Medicine
Coursera
Machine Learning
Coursera
Skills
Libraries/APIs
Scikit-learn, Pandas, XGBoost, NumPy, PySpark, PyTorch, TensorFlow, SpaCy
Tools
Microsoft Power BI, Git, Qlik Sense, BigQuery, GitLab, Bitbucket, GitHub
Languages
SQL, Python, Bash, R, SAS, Excel VBA
Frameworks
Streamlit, Flask, RStudio Shiny, Hadoop
Platforms
Linux, Google Cloud Platform (GCP), Dataiku, Oracle, Kubernetes, Docker
Storage
Data Pipelines, Apache Hive, Teradata
Other
Machine Learning, Statistical Modeling, Data Visualization, Predictive Modeling, Data Science, Data Analysis, Exploratory Data Analysis, Predictive Analytics, Data Cleaning, Data Modeling, Feature Engineering, Regression Modeling, Statistics, Linear Regression, Dashboards, Data Engineering, Machine Learning Operations (MLOps), Deep Learning, MLflow, Data Quality, Computer Vision, CI/CD Pipelines, Data Build Tool (dbt), Bayesian Statistics, Media Mix Modeling, Marketing Mix Modeling
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