
Speak is a language learning app that sets users on the path to fluency with the world’s most advanced AI tutor. Built on the core learning philosophy of getting users speaking out loud as much as possible, Speak's AI language-learning experience encourages dynamic two-way dialogue through personalized content and real-time speech recognition. Speak was founded by Connor Zwick and Andrew Hsu in 2016 to democratize access to high quality language education through AI. Backed by Y Combinator, Open AI, Founders Fund, Khosla Ventures, Matrix Partners and more, Speak is a series B startup with a global presence and offices in San Francisco, Seoul, Tokyo, and Ljubljana. Featured by Apple as the ‘App of the Day’ and ‘Best New App’, Speak is hiring across the globe. Come join us as we teach the next billion people English and reinvent the way the world learns, staring with language!

Speak is a language learning app that sets users on the path to fluency with the world’s most advanced AI tutor. Built on the core learning philosophy of getting users speaking out loud as much as possible, Speak's AI language-learning experience encourages dynamic two-way dialogue through personalized content and real-time speech recognition. Speak was founded by Connor Zwick and Andrew Hsu in 2016 to democratize access to high quality language education through AI. Backed by Y Combinator, Open AI, Founders Fund, Khosla Ventures, Matrix Partners and more, Speak is a series B startup with a global presence and offices in San Francisco, Seoul, Tokyo, and Ljubljana. Featured by Apple as the ‘App of the Day’ and ‘Best New App’, Speak is hiring across the globe. Come join us as we teach the next billion people English and reinvent the way the world learns, staring with language!
Company: Speak — AI-powered language-learning app
Founded: 2016
Core product: AI tutor focused on spoken conversational practice with real-time speech feedback
Recent funding: $78M Series C (Dec 2024) led by Accel; $1B valuation
Headcount (reported): 273 employees
Language education / skills learning focused on speaking fluency
2016
Software Development
$27M
$20M
Raised as a Series B extension; reported valuation $500M at time
$78M
Reported valuation $1B
“Backed by institutional investors including OpenAI Startup Fund, Khosla Ventures, Founders Fund, Accel, Buckley Ventures and angel investors such as Sam Altman and others”
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About Us 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.
About This Role We are looking for an experienced Machine Learning Engineer to join our team and help develop cutting-edge speech recognition models that help teach language fluency. In this role you will take ownership of the end-to-end modeling pipeline, from training and experimentation to deployment and monitoring. You will also work closely with Product teams to design innovative learning experiences and measure the efficacy of production models as they affect our end users. We are a small, dynamic team where you will contribute as a developer and thought partner on team projects like ASR, assessment, pronunciation, content personalization, and much more. This is an incredibly exciting time to join an ML team designing a personalized learning experience that will revolutionize language learning for millions of learners worldwide — come join us!
What you'll be doing
What we're looking for
Extensive experience training large models on GPUs and deploying custom deep learning models
Proficiency in Python and common Deep Learning frameworks like PyTorch
Demonstrated experience owning ML pipelines end to end, from POC to production
Strong communication skills and the ability to explain complex ML concepts to non-technical stakeholders
Sharp product sense and an ability to think broadly and cross-functionally about model quality in the context of user experience
Bonus
Experience with speech or audio
Office
Why work at Speak
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.