
Senior Principal Applied AI Scientist at Preply (London, United Kingdom)
Preply· London, United Kingdom·
Role details
Preply at a glance
A human-led, AI-enhanced online language-learning marketplace connecting 100,000+ tutors with millions of learners for live 1-on-1 lessons.
Preply is a two-sided online marketplace for live 1-on-1 language and skills tutoring. Learners browse tutors, take a trial lesson, and book recurring sessions in an integrated video classroom; Preply handles discovery, scheduling, and payments and takes a commission on lessons. It also runs Preply Business for corporate language training.
~$300M raised · latest: Series D · $150M · January 2026 · backed by WestCap, European Bank for Reconstruction and Development (EBRD), Horizon Capital, Owl Ventures
Job description
WE POWER PEOPLE’S PROGRESS.
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/Preply.com 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!).
OUR PRINCIPLES
- Care to change the world - We are passionate about our work and care deeply about its impact to be life changing.
- We do it for learners - For both Preply and tutors, learners are why we do what we do. Every day we focus on empowering tutors to deliver an exceptional learning experience.
- Keep perfecting - To create an outstanding customer experience, we focus on simplicity, smoothness, and enjoyment, continually perfecting it as every detail matters.
- Now is the time - In a fast-paced world, it matters how quickly we act. Now is the time to make great things happen.
- Disciplined execution - What makes us disciplined is the excellence in our execution. We set clear goals, focus on what matters, and utilize our resources efficiently.
- Dive deep - We leverage business acumen and curiosity to investigate disparities between numbers and stories, unlocking meaningful insights to guide our decisions.
- Growth mindset - We proactively seek growth opportunities and believe today's best performance becomes tomorrow's starting point. We humbly embrace feedback and learn from setbacks.
- Raise the bar - We raise our performance standards continuously, alongside each new hire and promotion. We build diverse and high-performing teams that can make a real difference.
- Challenge, disagree and commit - We value open and candid communication, even when we don’t fully agree. We speak our minds, challenge when necessary, and fully commit to decisions once made.
- One Preply - We prioritize collaboration, inclusion, and the success of our team over personal ambitions. Together, we support and celebrate each other's progress.
DIVERSITY, EQUITY, AND INCLUSION
Preply.com 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.
Why work at Preply
- Culture: Guided by five “Preply principles” (Ambition, Keep Perfecting, Care to Change the World, etc.). 86% of employees are proud to work at Preply (2025 survey); 84% would recommend it as a great place to work.
- Work model: Hybrid working model (flexible remote/in‑office). Main office in Barcelona with hubs in New York, London, and Kyiv.
- Perks: Competitive salaries, stock options, L&D days, monthly Preply platform allowance, wellness benefit, health insurance, flexible compensation program, after‑work gatherings, offsite events, enterprise OpenAI licenses.
- Hiring process: 4 stages – TA chat, interviews with hiring team (may include tech test), a final task (case study / peer programming / deep technical discussion), and a Culture Champion interview.
- Global team: 62+ nationalities and 700+ employees, offering a diverse, collaborative environment.