Senior Machine Learning Engineer - Applied AI & LLMs (x/f/m)

Free resume; Paris; Hybrid; EUR 120,000 - 160,000; Full time

Benefits offered by this job

Health insurance

Vacation days (25) & RTT

Mental health support

Relocation assistance

Lunch vouchers

Job summary

Doctolib is seeking a Senior Machine Learning Engineer to lead AI initiatives in Patient Solutions. You will architect and deploy AI systems, improve practitioner discovery, and evolve care pathways using large-scale retrieval and LLM/VLM capabilities.

This role emphasizes production-grade solutions, experimentation, and cross-functional collaboration within a hybrid Paris-based setting. Ideal candidates have 7+ years in ML/AI, strong IR and retrieval stack experience, and fluency in English.

Qualifications

• 7+ years of experience in Machine Learning, Deep Learning, or AI Engineering.

Responsibilities

• Design and implement ML/AI solutions aligned with patient product goals across search and care pathways.
• Build and maintain large-scale retrieval pipelines, hybrid search, embeddings, and multi-stage ranking.
• Develop, fine-tune, and benchmark LLM and VLM models; employ distillation and MoE architectures.
• Create agentic AI systems and integrate external tools via MCP-based integrations.
• Define metrics, run end-to-end experiments, and communicate results to product/engineering teams.
• Collaborate with ML platform team to deploy production-grade solutions with reliability and observability.

Skills

Information Retrieval

Hybrid search

Embeddings

Vector databases

LLM development

Prompt engineering

Experimentation

Agentic AI

Observability

Tools

LiteLLM

Model Garden

ADK

Job description

# Senior Machine Learning Engineer - Applied AI & LLMs (x/f/m)Doctolib· Paris, France· Posted 6/1/2026 On-site (Paris)contractLang: enApply on Company SiteTailor My Resume for this RoleDirect company application on jobs.ashbyhq.com. Zero third-party aggregator forms.## Job Description## Your ImpactWe are looking for a **Senior Machine Learning Engineer** to join the **ML Engineering** team in **Patient Solutions**.Your mission will be to improve how people access quality care and manage their health over time by building and leading AI and ML systems that create real, measurable impact. You will work in a feature team developing intelligent patient-facing solutions, from smart practitioner discovery to long-term care management, playing a key technical role in shaping how we scale our AI capabilities across Europe.Working in the tech team at Doctolib means building innovative products and features to improve the daily lives of care teams and patients.## ## What you'll doYour responsibilities include but are not limited to:* Design and implement ML and AI solutions aligned with patient product goals, covering search, retrieval, and personalized care pathways* Build and maintain large-scale retrieval pipelines, including hybrid search, embedding systems, vector databases, and multi-stage re-ranking architectures* Develop, fine-tune, and evaluate LLM and VLM models using techniques such as knowledge distillation, Mixture-of-Experts (MoE) architectures, and prompt engineering* Build and orchestrate agentic AI systems, integrating external data and capabilities through tools and MCP-based integrations* Define metrics aligned with product goals, run controlled end-to-end experiments using W&B, MLFlow, or Braintrust, and communicate findings to guide product and technical decisions* Deploy solutions to production in collaboration with our ML platform team, ensuring reliability, observability, and performance at scale, and act as a technical reference to elevate the team's standards and practices## ## Who you areBefore you read on: if you don't have the exact profile described below, but you feel this job description matches your skill set, we still encourage you to apply.**You'll be a great fit if you:*** You have 7+ years of experience in Machine Learning, Deep Learning, or AI Engineering, with a strong track record of taking models from prototype to production at scale* You have strong experience in Information Retrieval and modern retrieval stacks: hybrid search (sparse + dense), large-scale embeddings and vector databases, multi-stage retrieval and re-ranking pipelines, RAG architectures, and tool/MCP-based integrations* You are proficient in LLM and VLM application development: fine-tuning, MoE architectures (via LiteLLM or Model Garden), knowledge distillation, prompt engineering, and systematic benchmarking of LLM/VLM systems* You have hands-on experience building and orchestrating agentic AI systems (e.g., using ADK)* You demonstrate strong scientific rigor: designing metrics aligned with product goals, running controlled experiments, and communicating results clearly to both product and engineering stakeholders* You have experience operating large-scale applications in production (monitoring, reliability, performance, observability), bring strong analytical skills, and approach your work with a user-first mindset. You are fluent in English**It would be fantastic if you:*** Have experience in B2C marketplace environments* Have experience in other ML methodologies: pattern mining, recommendation systems, experimentation, or causal inference## ## Life at Doctolib Tech* Our solutions are built on a single fully cloud-native platform that supports web and mobile app interfaces, multiple languages, and is adapted to country and healthcare specialty requirements.* Our stack is composed of Rails, TypeScript, Java, Python, Kotlin, Swift, and React Native.* We leverage AI ethically across our products to empower patients and health professionals. Discover our AI vision here.*Want to learn more about our tech culture and environment? Visit the* *Doctolib Tech site**.*## ## What we offer* Free comprehensive health insurance (basic package) for you and your children* 25 days of paid vacation per year, plus up to 14 days of RTT* Free mental health and coaching services through our partner Moka.care* Work from abroad for up to 10 days per year thanks to our flexibility days policy* Lunch vouchers (Swile card) worth €8.50 per working day, with €4.50 covered by Doctolib* A subsidy from the work council to refund part of the membership to a sport club or a creative class* 50% reimbursement of your public transport subscription* ParentCare Program: Enjoy full salary coverage (100%) during your first month of birth leave, and 75% during the second, covered by Doctolib* Enrollment in Doctolib's long-term employee value sharing plan called DoctoGrowth* For caregivers and workers with disabilities, a package including an adaptation of the remote policy, extra days off for medical reasons, and psychological support* Relocation support in case of international mobility* Access to the best AI tools for coding, development and dedicated training## ## Our interview process* Recruiter Interview* Feature Building Interview* System Design Interview* Behavioral Interview* At least one reference checkWe want your experience to be clear, respectful, and transparent. Learn more about our hiring process on our candidate experience page.## ## Job details* Permanent position* Full-time* Location: Doctolib Paris office in Levallois-Perret* Hybrid work setup (3 days/week in the office)* Start date: as soon as possible## ## We welcome everyoneAt Doctolib, we are committed to improving access to healthcare for everyone. This translates into our recruitment process. We evaluate candidates based solely on qualifications and motivation, without any form of discrimination.The more diverse ideas are heard, the more our product will truly improve healthcare for all. You are welcome to apply to Doctolib, regardless of your gender, religion, age, sexual orientation, ethnicity, or disability.To ensure equal opportunities, we invite you to exclud