Senior Principal Applied AI Scientist Location: London

At Preply, we’re all about creating life-changing learning experiences. We help people discover the magic of the perfect tutor, craft a personalised learning journey, and stay motivated to keep growing. Our approach is human-led, tech-enabled - and it’s creating real impact. We’ve just reached unicorn status with a $150M Series D, accelerating our vision to transform education through human-led, AI-enhanced learning. Today, 100,000+ tutors teach 90+ languages to learners in 180 countries - and we’re only getting started. As a category-defining company, we’re shaping what the future of learning looks like at global scale. Every Preply lesson sparks change, fuels ambition, and drives progress that matters. Joining Preply means helping define the future of education at global scale, and building something that truly matters for millions of people, every day.

As a Senior Principal Applied AI Scientist, you will lead the development of AI-driven personalized learning solutions and shape Preply's scientific roadmap. Collaborating with a team of exceptional scientists and engineers, you will architect state-of-the-art models and systems that enhance the experiences of millions of learners worldwide. With a high level of autonomy and influence, you will report directly to the VP of Data and Applied AI, playing a pivotal role in setting the direction of our most ambitious AI initiatives.

What you’ll be doing:

• Innovative R&D: Leverage your extensive experience in Deep learning, NLP, Information Retrieval (IR), LLMs and multimodal AI to design and deploy scalable machine learning solutions for personalized learning and intelligent tutor systems.
• Scientific leadership: Develop long-term scientific roadmaps, aligning them with Preply’s product strategy and business goals. Act as a strategic advisor to senior leadership on investments, technology direction, and organizational planning.
• Cross-functional collaboration: Partner closely with applied science leaders, product managers, and engineering teams to deliver AI solutions that address user needs and unlock new business opportunities.
• Mentorship & knowledge sharing: Guide and mentor scientists and engineers, fostering a collaborative and innovative science community within Preply.
• Drive best practices: Establish and advocate for best practices in machine learning, including architecture design, research roadmaps, and deployment pipelines.

What you need to succeed:

• Academic and professional background: PhD in NLP, IR, Machine Learning, or related fields (or equivalent experience). 8+ years of industry experience, with a strong focus on deep learning-based NLP, LLM continuous pre-training, and IR methods.
• Scientific and technical expertise: Demonstrated expertise in retrieval models and extensive experience with ranking models. Strong understanding and experience with retrieval-augmented generation (RAG) and LLMs for real-world applications. Proficiency in deep learning frameworks such as PyTorch. Hands-on experience with cloud platforms (e.g., AWS, Google Cloud).
• Leadership & impact: Proven ability to lead scientific roadmaps across multiple product areas, aligning them with business objectives while collaborating with Product and Engineering. Track record of solving real-world problems throughout the entire product lifecycle, from research to production.
• Visionary mindset: A passion for driving scientific innovation to enhance personalized learning experiences. Strong collaboration skills and the ability to work cross-functionally with diverse teams.

Why you’ll love it at Preply:

• An open, collaborative, dynamic and diverse culture;
• A generous monthly allowance for lessons on Preply.com, Learning & Development budget and time off for your self-development;
• A competitive financial package with equity, leave allowance and health insurance;
• Access to free mental health support platforms;
• The opportunity to shape the lives of learners and tutors through language learning and teaching in 175 countries (and counting!).

Preply.com is committed to creating an inclusive environment where people of diverse backgrounds can thrive. We believe that the presence of different opinions and viewpoints is a key ingredient for our success as a multicultural Ed-Tech company. That means that Preply will consider all applications for employment without regard to race, color, religion, gender identity or expression, sexual orientation, national origin, disability, age or veteran status.