Senior Applied Scientist - Behavior AI

Datadog · Paris, France · Dev Eng · listed July 6, 2026

The shape of it

Seniority
Senior
Where
Hybrid
Requirements listed
8
Length
1,090 words

In the posting’s own words

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.

What it asks for · 8

  • 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.

What the job covers

  • 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.

Degree language

  • You have a BS/MS/PhD in Computer Science, Engineering, Machine Learning, Applied Mathematics, or a related scientific field, or equivalent experience.

Tools and skills named

Cloud & infra
  • Datadog4×
Models & research
  • GPU2×
  • Fine-tuning
  • Machine learning
Data
  • Data pipelines2×
Security & compliance
  • Security2×
Product & design
  • Roadmap
Ways of working
  • On-call

Words the posting leans on

  • models21×
  • build10×
  • constraints5×
  • product5×
  • production5×
  • record5×
  • fit4×
  • real4×
  • run4×
  • scale4×
  • stream4×
  • systems4×
  • training4×
  • applied mathematics3×
  • behavior3×
  • cost3×

Counted from the posting after the mission statement and the legal notices are set aside. The ones near the top are the ones a screener is looking for.

The posting, your resume, and the gaps between them. One click loads all three.

More open at Datadog

every open role at Datadog

How this page was made

An automated read of a public job posting, fetched August 25, 2026 and last changed by Datadog on August 24, 2026. Every list above is pulled from the posting’s own sentences — nothing rewritten, nothing added, no judgment about the role or the company. Counts and seniority are read off the text by rule, so they can be wrong where the posting is unusual. The original is the only thing that binds. Openings close without warning; check the source before spending an evening on it.