Full-Stack Engineer - Enterprise

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’re looking for a senior full-stack engineer to serve as a hands-on technical contributor for Speak for Business, the pod building the enterprise layer of Speak. You’ll work across the B2B product surface — partner portals, reporting, B2B subscription mechanics, admin experiences, and learner features that require an enterprise touch. You’ll work primarily in TypeScript across Node.js and Postgres, partnering with engineers in adjacent pods where experiences cross team boundaries. You’ll turn product requirements and business goals into clear technical designs, contribute hands-on across the stack, and help set a high bar for architecture, reliability, and code quality on a small, fast-moving team. Near-term work includes B2B onboarding flows, partner-facing reporting, subscription and billing mechanics, and enterprise-ready features that support our growing Sales and CS motion. What You’ll Be Doing - Building and owning full-stack features across the Speak for Business product surface, including partner portals, admin dashboards, reporting, and B2B subscription workflows - Designing and implementing backend services, APIs, and data models that support multi-tenant enterprise use cases - Leading cross-functional integrations across authentication, entitlements, billing, CRM, and analytics - Partnering closely with product, design, sales, and customer success to define scope and deliver end-to-end outcomes - Setting a high quality bar for privacy, security, observability, data integrity, and safe rollouts - Contributing to an AI-native development workflow — reviewing plans and designs before implementation, creating strong verification loops, and shipping safely with AI-assisted tooling - Mentoring engineers and raising the team’s bar for technical judgment and ownership What We’re Looking For - 6+ years of experience building production-scale web applications, with strong proficiency in TypeScript, Node.js, and SQL databases (Postgres preferred) - Full-stack capability — comfortable across both frontend and backend, with solid database fundamentals - Experience with or strong interest in B2B SaaS, enterprise product surfaces, or multi-tenant systems - Strong product and business judgment, with the ability to translate enterprise requirements into pragmatic scope and durable technical foundations - Experience designing APIs and backend services, reasoning clearly about system boundaries, and working with relational data - Ability to work autonomously and adapt quickly on a small team with low meeting overhead and high ownership expectations - Excellent cross-functional communication and a collaborative working style - Excitement about AI-assisted development, paired with thoughtful verification and a high production-quality bar - Nice to have: - Experience with multi-tenant B2B SaaS, SSO/SAML, billing, invoicing, or entitlements - Familiarity with admin dashboards, reporting, or analytics integrations - Experience with B2B account models, roles, or provisioning - CRM or marketing technology integrations - Experience building for both consumer and B2B surfaces WHY WORK AT SPEAK 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, Tokyo, and Taipei, 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.