What you’ll doAt Doctolib, we're on a mission to transform the way healthcare is delivered by leveraging the power of AI. As a Senior Machine Learning Engineer, you'll play a critical role in developing and implementing cutting-edge AI solutions that will simplify the access and quality of care for all.In this role, you'll have the opportunity to work with a team of talented Machine Learning Engineers, software engineers, ML ops and healthcare professionals to develop and deploy AI models that will have a real impact on people's lives.You will work at simplifying how patients find their healthcare practitioner, handle their care plan in the long term and work with business team to contribute expansion of Doctolib in several new markets.Doctolib is looking for a Senior Machine Learning Engineer to join our Machine Learning Engineer team in charge of our patient solutions.Your responsibilities include but are not limited to:Find the right technical solution to solve the product domain goalsImplement your ideas and test themDeploy your algorithms in production guided by our ML platform teamMeasure the uplift and continuously improve your approach Who you areYou could be our next team mate if you: Have strong analytical skills, are result oriented and user firstHave 7 years of experience in the domain of Machine Learning / Deep Learning / AI Engineering, including taking models from prototype to production at scale.Have deep experience in Information Retrieval and modern retrieval stacks, including some of the following:Hybrid search (sparse + dense)Large-scale embeddings and vector databases Multi-stage retrieval and re-ranking pipelinesRAG architectures and retrieval pipelines on multimodal use casesTool- and MCP-based integrations to bring in external data and capabilitiesProficient in LLM/VLM application development, including:Fine-tuning LLM and VLM modelsMixture-of-Experts (MoE) architectures (via LiteLLM or Model Garden)Knowledge Distillation Prompt engineering and tool useEvaluation and benchmarking of LLM/VLM systemsHave hands-on experience with agentic AI (e.g. building and orchestrating agents on top of ADK).Have demonstrated strong scientific rigor and benchmarking skills:Designing metrics aligned with product goals,Running controlled end to end experiments with W&B, MLFlow or BraintrustAnalysing and communicating results to guide product and technical decisions.Have experience with large scale applications in production (monitoring, reliability, performance, observability).Now, it would be fantastic if you: Have experience in B2C marketplace.Have experience in other ML methodologies : pattern mining, recommendation, experimentation or causal inference.What we offerFree health insurance for you and your childrenParent Care Program: receive one additional month of leave on top of the legal parental leaveFree mental health and coaching services through our partner Moka.careFor caregivers and workers with disabilities, a package including an adaptation of the remote policy, extra days off for medical reasons, and psychological supportWork from EU countries and the UK for up to 10 days per year, thanks to our flexibility days policyWork Council subsidy to refund part of sport club membership or creative classUp to 14 days of RTTA subsidy from the work council to refund part of the membership to a sport club or a creative class Lunch voucher with Swile cardThe interview process HR ScreenTechnical Deep DiveSystem DesignBehavioral Interviewat least one Reference check and Criminal records check Job detailsPermanent position Full TimeLocation: Doctolib Paris office in Levallois PerretWork mode: Hybrid 3 days/week in the officeStart date: asapIf you would like to find out more about tech life at Doctolib, feel free to read our latest Medium blog articles! 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, 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! All information provided is processed by Doctolib for application management. For data processing details, click here. Please contact hr.dataprivacy(at)doctolib.com for inquiries or to exercise your rights.