Staff Machine Learning Engineer
Doctolib
Staff Machine Learning Engineer
Doctolib
Online appointment booking and teleconsultation platform
We are looking for several Staff Machine Learning Engineers - Retrieval to join two AI teams that ground Doctolib's AI in trusted medical knowledge:
Medical Knowledge Platform grounds clinical decision support for health professionals in validated sources: HAS guidelines, learned society recommendations and peer-reviewed clinical studies, across more than 100 million documents.
Ground makes sure the answers of Doctolib's patient assistant, a conversational system of about twenty agents, rest on reliable medical knowledge.
In both teams, retrieval quality directly affects the reliability and safety of AI-powered healthcare experiences used by hundreds of thousands of health professionals and millions of patients 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.
Your responsibilities include but are not limited to:
Design and maintain both indexing pipelines and retrieval systems, with end-to-end ownership across the full retrieval stack
Operate at scale: architect and optimise systems for demanding volume and latency, up to 100M+ documents, 50+ req/s and sub-300 ms latency on the clinical side
Build custom re-rankers, optimise query processing pipelines, and design robust retrieval evaluation frameworks
Engineer deep RAG systems from the ground up, going well beyond off-the-shelf components to tackle real medical knowledge complexity
Design offline and online evaluations and controlled experiments around what actually helps users, and decide when retrieval is the right tool and when another grounding approach works better
Work across the full retrieval stack: vector embeddings, vector search, re-ranking, query expansion and rewriting
Help the engineers around you get better at retrieval
Before 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:
Have proven production experience building and scaling search & retrieval systems in a real-world, high-traffic environment
Bring deep dual expertise in both offline indexing and online retrieval; you own the full pipeline, not just one side of it.
Are genuinely hands-on with the retrieval tech stack: Elasticsearch, Solr, Vertex AI, vector search, embeddings, re-ranking and query processing.
Have gone beyond commodity RAG; you've built custom re-rankers, optimized indexing pipelines, or engineered query processing solutions that required real technical depth.
Have operated at Senior or Staff level, with the autonomy and technical depth that comes with it.
It would be fantastic if you:
Have experience working with medical knowledge sources, clinical databases, or healthcare information systems
Have contributed to evaluation frameworks and benchmarks for retrieval quality or AI outputs in regulated or high-stakes environments
Have worked in a multi-lingual retrieval context or with domain-specific ontologies
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.
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
Recruiter Screen (45')
Live Coding Interview (75')
System Design Interview (75')
Behavioural Interview (75')
Reference Check & Offer
We want your experience to be clear, respectful, and transparent. Learn more about our hiring process on our candidate experience page.
Permanent position
Tech stack: Python, Elasticsearch, Solr, Vertex AI, vector search, embeddings
Full-time
Levallois-Perret, France
Hybrid work setup (up to 2 remote days per week)
Start date: as soon as possible
At 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 exclude personal information (e.g., pictures, age) from your applications. If you require any accommodation, please let us know for support during the hiring process.
Join us in building the healthcare we all dream of!
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Doctolib runs a digital healthcare platform that connects patients with healthcare professionals, mainly in France, Germany, and Italy. It provides online appointment booking, teleconsultation, and practice-management tools through subscription-based software for medical practices, hospitals, and individual clinicians. The platform helps patients find and book care quickly while giving providers a centralized system to manage schedules, patient communications, and administrative tasks. Unlike many options that focus on one feature, Doctolib combines patient access with practice management in a single solution, serving multiple types of healthcare clients across several European countries. The company’s goal is to make healthcare more efficient and easier to access by streamlining operations for providers and reducing barriers to care for patients, using a scalable subscription model to grow across markets.
Explore more opportunities at Doctolib