Senior Applied Scientist (AI Platform)

Location: Paris, France; hybrid

Company

Datadog develops monitoring, observability, and AI platforms for production systems.

What you will do

• Own the applied science direction and methodology for Generative Simulations (GenSim).
• Define, measure, and improve the correctness, representativeness, and difficulty of post-training data.
• Research and engineer realistic, imperfect production environments with instrumented applications, representative traffic, and controlled failures.
• Build reliable, scalable synthetic-environment systems that can be invoked inside training loops.
• Determine how generated data should be used for LLM post-training and agent evaluation.
• Collaborate with Bits AI SRE, model training, engineering, and evaluation teams.

Requirements

• PhD, MS, or equivalent research experience in a scientific field with strong applied mathematics grounding.
• 6+ years of relevant applied science or ML engineering experience, including setting technical direction.
• Hands-on experience creating, managing, and evaluating LLM and agent post-training data.
• Domain expertise in LLMs and agentic applications, including agent or LLM application evaluation.
• Strong programming and production software engineering skills, including Python and distributed systems.
• Ability to make sound technical decisions in ambiguous environments and collaborate across science and engineering teams.

Nice to have

• LLM fine-tuning, post-training, or model training experience.
• Statistics, experiment design, and data analysis background.
• Production-level ML infrastructure deployment experience.
• Observability or monitoring systems experience.
• Architecture-level understanding of LLMs.

Culture & Benefits

• New-hire stock equity through RSUs and an employee stock purchase plan.
• Professional development, product training, and career pathing.
• Mentor and buddy programs for intra-departmental networking.
• Inclusive culture with Community Guilds and Inclusion Talks.
• Global Spring Health benefits for employees and dependents aged 6+.
• Competitive benefits, varying by country of employment and employment arrangement.