Senior Computational Linguist/Prompt Engineer in London

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 personalized learning journey, and stay motivated to keep growing. Our approach is human-led, tech-enabled - and it's creating real impact. So far, 90,000 tutors have delivered over 20 million lessons to learners in more than 175 countries. Every Preply lesson sparks change, fuels ambition, and drives progress that matters.

Role Overview

As a Computational Linguist (CL) / Prompt Engineer (PE) at Preply, your primary responsibility will be crafting, refining, and testing prompts designed to elicit high-quality insights from LLMs regarding how students learn languages. You will support our AI-driven educational platform by designing datasets and validation pipelines essential for prompt effectiveness.

What you'll be doing:

• Write, evaluate and optimize prompts for LLMs specifically targeted at analyzing language learning processes.
• Understand and employ prompt engineering techniques such as few‑shot prompting, chain-of-thought, and contextual framing (zero-shot, few-shot, etc.).
• Develop and maintain datasets for prompt validation, including designing annotation guidelines, performing quality control, and generating synthetic or crowdsourced data.
• Validate prompt outputs through both qualitative and quantitative evaluation procedures.
• Use Python for automated prompt testing and quality validation.
• Collaborate with engineers, product managers, and learning designers to improve prompt performance.
• Stay informed of best practices in prompt engineering and advances in NLP and LLM research.

What you need to succeed:

• Strong understanding of prompt engineering principles and experience with prompting LLMs.
• 2-3 years of experience in a similar role as a Computational Linguist or Prompt Engineer.
• Proficiency in Python scripting and familiarity with dataset creation and validation processes.
• Strong understanding of datasets, annotation workflows, and quality control in AI contexts.
• Analytical mindset and attention to detail, with a collaborative team spirit.
• Comfortable working in agile, cross-functional environments and handling multiple tasks efficiently.
• Enthusiasm for AI in education and motivation to shape Preply's next-gen learning tools.
• Bachelor's degree or higher in linguistics, English or Spanish.
• Excellent command of English (spoken and written) and linguistic precision.

Why you'll love it at Preply:

• An open, collaborative, dynamic and diverse culture.
• A generous monthly allowance for lessons on Learning & Development budget and time off for your self-development.
• A competitive financial package with equity, leave allowance and health insurance.
• Not in Barcelona? We offer an attractive relocation package to join us in our Preply Barcelona Hub.
• Pension Plan.
• Private health insurance.
• Access to free mental health support platforms.
• The opportunity to unlock the potential 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 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.