Senior iOS Engineer

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.

This is an extraordinary moment to join us. We're in the middle of a fundamental agentic shift in software development, and are embracing the change. We're operating in an agentic-first world, where the role of a builder is shifting from writing every line of code to designing systems that build, test, and improve themselves.

At Speak, you'll use AI agents as core collaborators in your day-to-day workflow—helping you move faster, explore more ideas, and focus on the highest-impact problems. That means embracing ambiguity, iterating quickly, and working fluidly across functions—not just within a single discipline.

We're looking for an iOS engineer who is excited to rethink how work gets done in an AI-native environment, and who want to help define what building looks like in this new paradigm.

As an iOS Engineer on Speak’s engineering team, you will be responsible for a variety of areas including improving how we serve our content, run A/B tests on monetization features, and supporting the launching of new markets and new languages. You will collaborate closely with backend engineers and our partners in Product and Design. You’ll be responsible for shipping product features to millions of users.

• Improve “freemium” experience to increase conversions

• Support the launching of new markets and new languages

• Implement various paywall tests, such as pricing, design changes, delayed paywalls, discounted offers, etc.

• Improve our speech-to-text system

• Improve our audio and video streaming systems

• 5+ years of industry experience working as a Mobile Engineer, preferably in a fast-paced startup environment

  • bonus: worked on an app that has been used by 1M users

• Proficiency in Swift, with a strong understanding of common mobile architectures including MVC/MVVM

  • bonus: Experience in SwiftUI

  • bonus: Experience in mobile streaming technologies (websockets, ll-hls)

• Experience using coding agents (e.g. Claude Code, Codex, Cursor) as core collaborators in your day-to-day workflow — not just as autocomplete, but as active partners in designing, testing, and shipping.

• Knowledgable in mobile build practices(eg jenkins, bitrise)

• Knowledgable in Apple StoreKit/RevenueCat

• Excellent problem-solving and communication skills, and the ability to work independently or as part of a team

• Coach and mentor other engineers

• Strong product sense: ability to think broadly/cross-functionally about 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.