Senior Applied Scientist - Behavior AI

Software Careers; Paris; Sur place; EUR 140 000 - 200 000; Plein temps

Résumé du poste

Datadog is seeking a Senior Applied Scientist for Behavior AI in Paris. You will design, train, and optimize models that process billions of logs in real time, focusing on high-throughput streaming and cost-efficient deployment.

You will build data pipelines, integrate models with production systems, and develop interpretability tools while maintaining operations across the platform. Strong math, ML, and software design skills are essential.

Qualifications

• Advanced degree in CS, engineering, ML, or applied math or equivalent experience.
• Hands-on experience training and fine-tuning models at scale in production.
• Strong math background and ability to reason about trade-offs between speed and accuracy.

Responsabilités

• Design and build mid-size models for high-throughput stream processing and train at scale.
• Optimize models across mathematics and systems for hardware efficiency.
• Build training data pipelines from raw streams to training-ready datasets.
• Collaborate with engineering to deploy models with attention to GPU utilization, latency and cost.
• Plan roadmap of model and system improvements tied to product needs.
• Develop an agentic layer to analyze, validate, and act on outputs.
• Create lightweight interpretability tools to explain model behavior.
• Maintain and monitor models, services and infrastructure; participate in on-call rotation.

Connaissances

Model Design

Model Training

Model Optimization

High-throughput Stream Processing

Anomaly Detection

Data Pipeline Development

Production Integration

GPU Utilization

Latency Optimization

Cost Optimization

Model Interpretability

Monitoring

On-call

Software Design

Machine Learning

Applied Mathematics

Computer Science

Engineering

Communication Skills

Efficient Sequence Architectures (Bonu

Large-scale Streaming Systems (Bonus)

Formation

BS/MS/PhD in CS/Engineering/ML/Applied Math

Outils

GPUs

Description du poste

# Senior Applied Scientist - Behavior AIat Datadog • Paris, FranceBack to jobs1. Home2. Jobs3. Senior Applied Scientist - Behavior AI1h agoD## Senior Applied Scientist - Behavior AIDatadog10EngineeringFull-timeParis, FranceApply Job### Job DescriptionThe Behavior AI team builds the AI-based anomaly detection behind Datadog's security products. Our models learn what normal looks like across the billions of logs, events, and telemetry records flowing through the platform every second, and they flag the behavior that does not fit, on every record, in real time, at a cost that makes sense at our scale. What we build does not ship to a single feature. The same models power detection across many of Datadog's security products at once, so the work has impact well beyond any one team. Large general-purpose models are too slow and too expensive to run in that path, so we take the opposite approach: small, custom models, designed for high-throughput stream processing and optimized to run cheaply on every record.We are hiring a Senior Applied Scientist to build these models from start to finish. You will contribute to designing the architecture, training at scale, and the optimization work that takes a model from training to running efficiently on production traffic. This optimization requires a deep understanding of the constraints imposed by both the software and the hardware, together with the applied mathematics to work within them: often it comes down to finding a mathematical reformulation that fits those constraints better, and that judgment can decide whether a model reaches production at all.The work involves a number of open questions. How do you obtain most of the quality of a large model from one that is far smaller and cheap enough to run on the full stream? Where is it worth trading exactness for speed, and how do you reason about the error you accept? How do you make a small model's outputs clear enough that the detection engineers and analysts who rely on it can trust what it reports? If these are the problems you want to work on, we would like to hear from you.At Datadog, we place value in our office culture: the relationships and collaboration it builds, and the creativity it brings to the table. We operate as a hybrid workplace to ensure our Datadogs can create a work-life harmony that best fits them.What You'll Do:Design and build custom mid-size models for high-throughput stream processing, and train them at scale.Optimize these models from start to finish, working across both the mathematics and the systems, often by finding mathematical reformulations that fit the hardware and software constraints better.Build the training data pipelines the work depends on when they do not already exist, from the raw stream to a training-ready dataset.Work with engineering to integrate models into production, with a clear focus on GPU utilization, latency, and cost per record on live traffic.Plan the roadmap of model and system improvements, based on a solid understanding of the product and of what matters most to users.Build an agentic layer on top of the models to analyze, validate, and act on their outputs.Build lightweight interpretability tools that make model behavior easier to explain to the people who rely on it.Maintain and monitor the models, services, and infrastructure your team owns, and take part in your team's on-call rotation.Who You Are:You have a BS/MS/PhD in Computer Science, Engineering, Machine Learning, Applied Mathematics, or a related scientific field, or equivalent experience.You have hands-on experience training and fine-tuning models at scale, and deploying them into production systems with real throughput and cost constraints.You have a working knowledge of how GPUs work, and a track record of making models run efficiently within real hardware constraints.You have strong applied-mathematics fundamentals and reach for them naturally when designing and optimizing models.You have a real passion for applied mathematics, software design, and implementation. This role sits at the intersection of the three, and it is a requirement for the position.You care about code simplicity and performance, and you can build the data pipelines and the surrounding production code, in addition to the models themselves.You can explain complex ideas and trade-offs clearly to engineers and product partners, and you let a solid understanding of the product guide what you build next.Bonus: experience with efficient sequence architectures, model interpretability, or large-scale streaming systems.### Skills Required* Model Design* Model Training* Model Optimization* High-throughput Stream Processing* Anomaly Detection* Data Pipeline Development* Production Integration* GPU Utilization* Latency Optimization* Cost Optimization* Agentic Layers* Model Interpretability* Monitoring* On-call* Computer Science* Engineering* Machine Learning* Applied Mathematics* Software Design* Implementation* Code Simplicity* Performance Optimization* Communication Skills* Efficient Sequence Architectures (Bonus)* Large-scale Streaming Systems (Bonus)