Senior Applied Scientist - Behavior AI

Datadog Datadog · Enterprise · Paris, France · Dev Eng

Senior Applied Scientist role focused on building and optimizing custom, small-to-mid-size AI models for real-time anomaly detection in security products. The role emphasizes designing architectures, training at scale, and optimizing models for production constraints (hardware, software, cost, latency) with a focus on GPU utilization and cost per record. It also involves building data pipelines, interpretability tools, and an agentic layer for output analysis.

What you'd actually do

  1. Design and build custom mid-size models for high-throughput stream processing, and train them at scale.
  2. 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.
  3. Build the training data pipelines the work depends on when they do not already exist, from the raw stream to a training-ready dataset.
  4. Work with engineering to integrate models into production, with a clear focus on GPU utilization, latency, and cost per record on live traffic.
  5. Build an agentic layer on top of the models to analyze, validate, and act on their outputs.

Skills

Required

  • BS/MS/PhD in Computer Science, Engineering, Machine Learning, Applied Mathematics, or related field, or equivalent experience.
  • Hands-on experience training and fine-tuning models at scale.
  • Experience deploying models into production systems with real throughput and cost constraints.
  • Working knowledge of GPU functionality.
  • Track record of making models run efficiently within real hardware constraints.
  • Strong applied-mathematics fundamentals.
  • Experience building data pipelines.
  • Experience building surrounding production code.
  • Ability to explain complex ideas and trade-offs clearly to engineers and product partners.

Nice to have

  • experience with efficient sequence architectures
  • model interpretability
  • large-scale streaming systems

What the JD emphasized

  • real throughput and cost constraints
  • run efficiently within real hardware constraints
  • applied mathematics
  • mathematical reformulation
  • GPU utilization
  • latency
  • cost per record

Other signals

  • custom models
  • high-throughput stream processing
  • optimization for production constraints
  • cost efficiency at scale