Lead Engineer / CTO

The Opportunity

We’re building scalable AI systems that save lives. We provide online mental health support at the moment young people need it most. Our approach is to reach young people where they are — online — and embed our interventions into the platforms they use every day (e.g., TikTok, Discord). 

We're looking for a technical leader with deep insight into AI's capabilities while maintaining a strong grasp of the ethical, safety, and privacy implications — particularly in sensitive domains like youth mental health.

Core Requirements

• Proven track record of independently building and shipping full-stack applications that solve real user needs, with a focus on product-market fit and user outcomes.
• Strong foundation in data science and machine learning, with experience using data to drive product decisions, design and analyze A/B tests, and measure impact.
• Deep understanding of modern AI capabilities and limitations, balanced with pragmatic product sense - you know when AI adds genuine value versus when simpler solutions would better serve users.
• Experience navigating complex ethical considerations in technology, particularly around safety, privacy, and responsible AI deployment.
• Demonstrated ability to move quickly and innovate while maintaining rigorous. standards for safety and efficacy, especially when serving vulnerable populations
• Technical depth to evaluate and implement AI solutions when appropriate, while maintaining focus on core user needs and scalable impact.

Key Responsibilities

• Build and evolve our platform architecture, creating interfaces and systems that effectively combine AI capabilities with intuitive user experiences.
• Design and implement robust experimentation frameworks to continuously measure and improve the effectiveness of our services.
• Drive product decisions through data analysis, translating insights into features that measurably improve mental health outcomes.
• Ship and iterate on production features across our platform ecosystem (TikTok, Discord, etc.), directly impacting millions of young people.
• Advance the field of AI and digital mental health by contributing to peer-reviewed research and open-source initiatives, sharing insights that can help the broader community.

What We Offer

• Opportunity to shape both the technical vision and social impact of an organization reaching millions.
• Fun, dynamic team that knows how to ship quickly and responsibly.
• Access to a deep network of AI practitioners and leaders.
• Flexible hours, fully remote, international offsites, no-meeting Fridays.
• Pay will be competitive with for-profit tech orgs, based on experience.

Technology

• Ruby on Rails backend.
• Custom yaml chat scripting language.
• Integration with LLMs. 
• Rust native library for embedded keyword detection. 
• Rust Discord bot. 
• Multiple next.js and react apps for user facing applications.

Our Values

• Make a difference: Aim for large effects. Scale and impact should astonish people.
• Be outcomes-based. Don’t just assume we are helping people. Measure it.
• Act with integrity: Be honest, ethical and genuine.
• Challenge yourself: Do hard things you’ve never tried before. Do hard things no one’s ever tried before.
• Find balance: Have your work match your lifestyle, not your lifestyle match your work.

At Koko, we celebrate diversity and are committed to creating an inclusive environment for all employees. We serve a very diverse user base and welcome applications from individuals of all backgrounds. Many of the people working with us are former Koko users themselves.