Junior Data Scientist (ML)

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.

Meet the team!
At Preply, AI isn't a feature — it's foundational. It powers how we connect millions of learners and tutors, personalize every interaction, and build a marketplace where meaningful learning thrives at global scale.

The Applied AI team sits at the center of this ecosystem. We design and deploy intelligent systems that drive real-time tutor–learner matchmaking across millions of sessions worldwide. Over time, we've evolved from traditional machine learning approaches into a modern AI-native marketplace — leveraging deep learning, advanced ranking and re-ranking architectures, and proprietary multimodal data including audio, video, and transcripts to deliver smarter recommendations and measurable learning outcomes.

As a Junior Data Scientist, you’ll join the AI Marketplace team. We build and operate the intelligence layer that ensures the marketplace is not only high-performing, but also safe and trustworthy — from neural ranking models in PyTorch to large-scale experimentation infrastructure and full-spectrum Trust & Safety systems, including fraud prevention, abuse detection, and marketplace integrity.

Today the team is made up primarily of senior scientists focused on advancing model architecture and large-scale AI systems. You will have ownership of high-impact, well-scoped work — such as feature engineering, data pipelines, offline evaluation tooling, and experiment analysis — while receiving close mentorship from experienced ICs.

Please note: This role is open to candidates based in Ukraine. You can work from our Kyiv hub or remotely from anywhere in Ukraine.

What you'll be doing:

• Building ML solutions that enable a remarkable user experience in the Preply marketplace.
• Contributing to data pipelines that power the team’s ranking and matching models, with support from senior engineers.
• Building and improving offline evaluation tooling and data quality checks.
• Analyzing experiment results to help the team understand model performance and guide future iterations.
• Owning well-scoped components of larger AI projects, with close guidance from senior teammates.

What you need to succeed:

• Strong understanding of machine learning fundamentals.
• Hands-on machine learning experience through internships, research, personal projects, or industry work.
• Experience with Python, Pytorch and Github.
• Curiosity, a growth mindset, and the ability to learn quickly from feedback.
• Familiar with AI tools to improve productivity and learning.
• English proficiency at B2 level or above.

Why you'll love it at Preply:

• An open, collaborative, dynamic and diverse culture;
• A generous monthly allowance for lessons onPreply.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!).

• 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.

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.