Applied ML Engineer, LLM

Our mission is to reinvent the way people learn, starting with language.

Learning a language can change a life by opening doors to new cultures, careers, and communities. Two billion people around the world are actively trying to learn a language, but the best way to learn (one-on-one tutoring) is hard to access at scale and hasn’t been meaningfully improved in decades. Speak is building a human-level, AI-powered tutor in your pocket: a conversation-first experience that lets learners actually speak, get instant feedback, and progress through carefully designed lessons. The result is a complete path from beginner to confident speaker across multiple languages.

Speak first launched in South Korea in 2019, where Speak has now become the number one language learning app, and we now serve learners across many markets and 15+ languages. Speak is one of the world’s leading AI companies, with over $150m raised in venture investment from OpenAI, Accel, Founders Fund, Khosla Ventures, and more, with a distributed team across San Francisco, Seoul, Tokyo, Taipei, and Ljubljana.

As an MLE at Speak, you'll play a pivotal role in developing the future of language learning and creating the most effective path to language fluency. Your primary responsibility will be to spearhead new proofs-of-concept and experiment creatively to help push the boundaries of truly personalized language learning.

Your tasks will span the entire ML lifecycle, from ideation and experimentation to implementation and deployment. You’ll bring the rigor of ML applied research to building out novel LLM product experiences to create new lesson types, to improve assessment/feedback, and to provide a continuously personalized learning experience to users.

We're constantly pushing the boundaries of what LLMs can do to provide an exceptional and unparalleled language learning experience to users in over 30 countries worldwide.

• Collaborating with the Content team to build out a Knowledge Graph to measure and track learner progress over time in Vocab, Grammar, and Pronunciation

• Building new types of dynamically-generated personalized lessons to teach to each individual learner’s strengths and weakness

• Working closely with the Product team to enhance our AI-powered lessons and learning features

• Improving the assessment and monitoring of our prompts via synthetic evaluators

• 3+ years experience as a machine learning engineer shipping ML systems into production

  • Proficiency in Python

  • Please apply if you have extensive experience building with LLMs, even if you’re more junior!

• Experience working with LLMs and strong LLM intuition

  • Experience building and shipping complex LLM systems into production: evaluation, prompt engineering, prompt chaining, finetuning, etc.

  • You’ve probably done several LLM hackathons, built several side projects, tried out many types of models, and use ChatGPT daily.

  • Strong understanding of improving performance & output quality of LLM systems: i.e. prompting vs finetuning, evaluation, model selection, etc.

• Strong product interest and sense - ability to think broadly/cross-functionally about novel LLM-powered capabilities and product experiences

• San Francisco, CA

1. Join a fantastic, tight-knit team at the right time: we're growing very quickly, we've most recently raised our Series C from some of the top investors in the valley, and we've achieved product-market fit in our initial markets. You'd join at a magical time when a single person could significantly change the course of the company.

2. Do your life's work with people you’ll love working with: we care strongly about our craft and want every person at Speak to feel like they're growing every day. We believe in the idea that working with people you both enjoy and have respect for makes everything better. We hire thoughtfully and only work with people we admire deeply.

3. Global in nature: We're live in over 40 countries and launching in a number of new markets soon. We have dedicated offices in San Francisco, Ljubljana, Seoul, and Tokyo, and you’ll have the opportunity to talk to users in each of these regions on a regular basis as well as travel.

4. Impact people's lives in a major way: Learning a language is one of the single most life-changing skills one can learn, and right now 99% of people never achieve their goal because the process is broken. We’re helping millions of people achieve their goals and improve their lives.

Speak does not discriminate based upon race, religion, color, national origin, gender (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, or other applicable legally protected characteristics.