Speak

About the Company

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.

Listed Jobs

Company Name

Speak

Job Title

Applied ML Engineer, Speech

Job Description

**Job Title** Applied ML Engineer, Speech **Role Summary** Design, build, and maintain end‑to‑end automatic speech recognition (ASR) and pronunciation models that provide real‑time feedback in a language‑learning app. Own the full machine‑learning lifecycle—from dataset creation and training to deployment, monitoring, and iterative improvement—while collaborating closely with product and data teams to align model performance with user experience goals. **Expectations** - Deliver robust ASR and pronunciation models at scale, optimizing for latency and accuracy across multiple languages. - Expand model coverage to new languages and regions, ensuring consistent performance benchmarks. - Champion data quality, orchestrating labeling, validation, and evaluation pipelines to support continuous learning. - Translate product requirements into measurable model metrics and communicate findings to non‑technical stakeholders. **Key Responsibilities** - Train large‑scale ASR models on GPU clusters, tuning hyperparameters and applying knowledge‑distillation techniques. - Deploy models in production environments, set up CI/CD pipelines and automated monitoring for drift, error rates, and inference latency. - Develop metrics for ASR and pronunciation quality; run A/B tests to assess impact on user engagement and learning outcomes. - Design and maintain data infrastructures: datasets, labeling workflows, feature stores, and evaluation harnesses. - Collaborate with cross‑functional teams (product, UX, data engineering) to integrate models into the app and refine learning experiences. **Required Skills** - Strong Python programming and expertise in deep‑learning frameworks (PyTorch, TensorFlow). - Proven experience building and deploying large‑scale speech/audio models on GPUs. - End‑to‑end ML pipeline ownership, from proof‑of‑concept to production. - Ability to translate complex ML concepts into clear, actionable insights for non‑technical audiences. - Product‑oriented mindset, assessing model quality in the context of user experience and business impact. - Excellent communication, documentation, and collaboration skills. **Required Education & Certifications** - Bachelor’s degree in Computer Science, Electrical Engineering, or equivalent professional experience. - Familiarity with ML engineering best practices, CI/CD, and cloud deployment (AWS, GCP, or Azure). **Bonus** - Prior experience with speech or audio signal processing (e.g., MFCCs, spectrograms). - Exposure to multilingual ASR systems and cross‑lingual transfer learning.

San francisco bay, United states

Hybrid

18-02-2026