About Doctolib

At Doctolib, we build innovative healthcare technology that improves the daily lives of healthcare professionals and patients. Our products measurably improve outcomes for care teams and patients, helping transform the future of healthcare.

Position: Principal Machine Learning Engineer

We are looking for a Principal Machine Learning Engineer to join the DS & AI organization at Doctolib.

This is a transversal force multiplier role operating across all AI teams: Clinical, Productivity, Phone Assistant, and ASR. Rather than working within a single feature team, you will own cross-cutting technical challenges, including defining how Doctolib’s product and AI teams build agentic solutions, standardizing ML evaluation frameworks, and spreading strong engineering practices across the organization.

You will unblock teams, shape architecture decisions, and take on deep technical challenges requiring senior ML judgment at scale. Your work will directly impact the daily lives of 400,000 healthcare professionals and 80 million patients.

What You’ll Do

Technical Strategy & Architecture

• Own cross-team ML architecture decisions, from model selection to production deployment patterns and strategic build-versus-buy decisions.
• Define and drive the adoption of rigorous evaluation frameworks across all AI teams, setting the standard for how Doctolib measures model and agentic performance.
• Establish shared production infrastructure patterns for AI, including model and prompt versioning, guardrails, uncertainty quantification, cost optimization, and observability.
• Lead the technical design of agentic solutions and define how product teams across Doctolib build on top of AI capabilities.
• Elevate technical standards across the DS & AI organization by influencing Staff and Senior ML Engineers through architecture reviews, technical guidance, and the propagation of best practices.
• Partner with Product, Legal, and Compliance teams to ensure safe rollouts and meet EU regulatory expectations, including GDPR, MDR, and the EU AI Act.

What You’ll Bring

Before you read on, if you don’t have the exact profile described below but feel this job description matches your skill set, we still encourage you to apply.

You’ll be a great fit if:

• 10+ years of experience in ML/AI, including 3+ years at Staff+ or Principal level leading complex, multi-team technical initiatives.
• Deep expertise in at least two of the following areas: clinical NLP, LLM fine-tuning and evaluation, automatic speech recognition, RAG systems, or reinforcement learning.
• Expertise in Python and PyTorch/Transformers for training, as well as vLLM for inference, with a proven track record of deploying ML systems into production on AWS or GCP.
• A PhD in Computer Science, AI, Statistics, or a related field, or equivalent research experience.
• Exceptional communication skills and the ability to align diverse stakeholders and explain complex technical decisions clearly.

Nice-to-Have Skills

It would be fantastic if you also have:

• Publications at top-tier ML/AI conferences such as NeurIPS, ICLR, or ACL, or in medical informatics publications.
• Experience with EU healthcare regulations, including GDPR, MDR, and the EU AI Act.
• Previous experience working with clinical data or healthcare applications.

Life at Doctolib Tech

Our solutions are built on a single, fully cloud-native platform supporting web and mobile interfaces across multiple languages and healthcare specialties.

Our technology stack includes:

• Rails
• TypeScript
• Java
• Python
• Kotlin
• Swift
• React Native

We leverage AI ethically to empower patients and healthcare professionals. We invite you to discover our AI vision and learn more about our tech culture and working environment through the Doctolib Tech site.

What We Offer

• Deutschlandticket: A fully paid Germany-wide public transport pass.
• Vacation Days: 28 vacation days, plus one additional day for each full calendar year of employment, up to a maximum of 30 days.
• Work from Abroad: Work remotely from abroad for up to 10 days per year through our flexibility days policy.
• Health Insurance: Company health insurance with excellent supplementary benefits through our partner Allianz.
• Company Pension Scheme: A company pension plan (bAV) through Allianz, with an employer subsidy of 40% (15% during the probationary period).
• Parental Benefits: Access to the Doctolib Parent Care program, including one additional month of parental leave and much more.
• Employee Value Sharing: Enrollment in Doctolib’s long-term employee value-sharing plan, DoctoGrowth.
• Mental Health & Coaching: Free mental health and coaching services through our partner Moka.care.
• Sports Membership: Subsidized sports membership through Urban Sports Club.
• Flexible Workplace: A flexible workplace policy offering both hybrid and office-based working arrangements.
• Food & Snacks: Healthy snacks, a regular breakfast buffet, and a subsidized meal benefit.
• Caregiver & Disability Support: A dedicated support package for caregivers and employees with disabilities, including adaptations to the remote work policy, additional days off for medical reasons, and psychological support.
• Relocation Support: Assistance in case of international relocation.
• AI Tools & Training: Access to leading AI tools for coding and development, as well as dedicated training opportunities.

The Interview Process

Our recruitment process consists of the following stages:

• HR Screening.
• Hiring Manager Interview.
• System Design Interview.
• Behavioral Interview.
• Case Study.
• At least one Reference Check.

We want your experience throughout the recruitment process to be clear, respectful, and transparent. Learn more about our candidate experience.

Job Details

• Employment Type: Permanent position.
• Working Hours: Full-time.
• Location: Berlin, Germany.
• Working Model: Hybrid, with up to two remote days per week.
• Start Date: As soon as possible.

Diversity & Inclusion

At Doctolib, we believe in improving access to healthcare for everyone, regardless of where you come from or what you look like. We evaluate candidates solely on their qualifications and motivation, without any form of discrimination. We respect and celebrate diversity!

The more diverse ideas we hear, the more our products can truly improve healthcare for everyone. You are welcome to apply regardless of gender, religion, age, sexual orientation, ethnicity, disability, or place of origin.

To ensure equal opportunities, we invite you to exclude personal information, such as pictures and age, from your application.

If you have a disability, please let us know if there is anything we can do to make the interview process more comfortable and accessible for you.

Join Us!

Join us in building the healthcare we all dream of. We look forward to receiving your application!