Chief Technology Officer in London

About the Role

A1 is building a proactive AI chat app for everyday users to bring intelligence to conversations, errands, organising and workflows. Unlike traditional chat-based applications, our product focuses on achieving high reliability for long-running workflows, persistent context, and real-world task completion. The system must handle multi-step reasoning, interact with external tools, and remain reliable despite non-deterministic model behaviour.

We are looking for a leader who can think clearly about systems, make strong technical decisions, and help build the engineering organisation from the ground up. Be part of the founding team to shape the technical direction of the company, while helping build a strong engineering team across the globe.

What You'll Do

• Technical Direction
  • Define the long-term architecture for A1’s AI systems, infrastructure, and developer platform
  • Evaluate trade-offs between speed of iteration and long-term system design
  • Ensure systems are designed for scalability, reliability, and long-term evolution
  • Guide key decisions across model integration, data pipelines, distributed systems, and product architecture
• Engineering Leadership
  • Work with engineers to translate product direction into clear technical execution
  • Help structure engineering workstreams and keep teams aligned on priorities
  • Maintain high engineering standards while keeping the team focused on shipping
  • Establish engineering culture, development practices, and technical standards across the company
• Building the Team
  • Build and scale a world-class engineering team across key talent hubs including China and US
  • Identify strong technical leaders and help build a high-quality engineering organization
  • Define hiring standards and interview processes to maintain a high engineering bar
• Coordination and Execution
  • Work closely with product, research, and leadership teams
  • Ensure technical workstreams move forward smoothly across teams and locations
  • Help resolve cross-team technical and execution challenges

What You Will Need

• Strong technical foundation in system architecture, large-scale systems, distributed architecture.
• Ability to reason clearly about complex systems and make pragmatic technical decisions
• Experience building or leading high-performing engineering teams
• Strong judgment on technical trade-offs and engineering priorities
• Comfortable operating in early-stage environments with high ambiguity
• Clear communication and ability to align teams

We are particularly interested in candidates who enjoy building teams, superior products and shaping engineering organisations.

How We Work

The best products today in the world were built by small, world class teams. We are a high talent density and hands-on team. We make decisions collectively, move at rapid speed, striking a balance between shipping high quality work and learning. Joining our team requires the ability to bring structure, exercise judgment, and execute independently. Our goal is to put in the hands of our users a truly magical product.

Interview process

If there appears to be a fit, we'll reach out to schedule 3, but no more than 4 interviews. Applications are evaluated by our technical team members. Interviews will be conducted via virtual meetings and/or onsite. We value transparency and efficiency, so expect a prompt decision. If you've demonstrated the exceptional skills and mindset we're looking for, the process to offer may be shorter.