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
- AI Research Engineer - Datadog AI Research (DAIR)Paris, France
- AI Research Scientist - Datadog AI Research (DAIR)New York, New York, USA
- AI Research Scientist - Datadog AI Research (DAIR)Paris, France
- Area Vice President, Sales EngineeringBoston, Massachusetts, USA; Denver, Colorado, USA; New York, New York, USA; San Francisco, California, USA
- Associate Field Marketing Manager (US East and Canada)New York, New York, USA
- Associate Growth Marketing ManagerNew York, New York, USA; San Francisco, California, USA