At a Glance
- Tasks: Lead the development of innovative AI systems that redefine team collaboration.
- Company: Exciting stealth-stage AI startup with a dynamic founding team.
- Benefits: Competitive salary, opportunity to shape the future, and work with top-tier founders.
- Other info: Join a fast-paced environment with significant growth potential.
- Why this job: Be the first engineering hire and make a real impact in the AI space.
- Qualifications: Senior-level experience in TypeScript, React, and Node.js required.
The predicted salary is between 80000 - 100000 € per year.
Join a high-velocity founding team building the operating system for the agentic era. You will architect a real-time, multiplayer agent system that automates coordination work through proprietary semantic memory and symbolic control. This role bridges complex LLM workflows and high-performance front-end engineering to redefine how teams collaborate in the modern workplace.
Location: London, UK or San Francisco, USA
Why this role is remarkable:
- You will be the first engineering hire, working directly with founders from top-tier academic and commercial backgrounds to define the technical foundation.
- The company is backed by top-tier global VCs and has already secured active procurement with major enterprise partners despite being in early stealth.
- You will build a new paradigm for work beyond simple chatbots, focusing on structured agent-to-agent negotiation and first-principles AI infrastructure.
What You Will Do:
- Own the end-to-end development of agentic systems, including multi-step LLM pipelines, structured outputs, and real-world agent negotiation loops.
- Architect and scale deep integrations with major productivity tools like Slack, Notion, and Linear to build a comprehensive world model.
- Optimize front-end performance to ensure the web and mobile applications feel instantaneous despite complex backend graph traversals and AI processes.
The ideal candidate:
- Proven senior-level experience in TypeScript, React, and Node.js, with a track record of shipping complex production systems at scale.
- Deep hands-on expertise with LLM orchestration, including experience with evals, streaming, caching, and building reliable agentic workflows.
- High-agency mindset with 0-to-1 experience, capable of owning product features from initial specification through to production deployment in a high-trust environment.
Founding Senior Full-Stack Engineer at stealth-stage AI coordination startup in London employer: Jack & Jill
As a Founding Senior Full-Stack Engineer at our stealth-stage AI coordination startup, you will be part of an innovative team in London or San Francisco, where your contributions will directly shape the future of collaborative technology. We offer a dynamic work culture that fosters creativity and autonomy, alongside opportunities for professional growth as you collaborate with industry-leading founders and tackle complex challenges in AI. With backing from top-tier VCs and partnerships with major enterprises, this role provides a unique chance to make a significant impact in a rapidly evolving field.
StudySmarter Expert Advice🤫
We think this is how you could land Founding Senior Full-Stack Engineer at stealth-stage AI coordination startup in London
✨Tip Number 1
Network like a pro! Reach out to people in the industry, especially those connected to the startup scene. Attend meetups or tech events in London or San Francisco to make those valuable connections that could lead to job opportunities.
✨Tip Number 2
Show off your skills! Create a portfolio showcasing your projects, especially those involving TypeScript, React, and Node.js. This is your chance to demonstrate your expertise in building complex systems and how you can contribute to the team.
✨Tip Number 3
Prepare for technical interviews by brushing up on LLM orchestration and agent negotiation loops. Practice coding challenges and system design questions to show you can handle the high-performance demands of the role.
✨Tip Number 4
Apply through our website! It’s the best way to ensure your application gets noticed. Plus, we love seeing candidates who take the initiative to connect directly with us.
We think you need these skills to ace Founding Senior Full-Stack Engineer at stealth-stage AI coordination startup in London
Some tips for your application 🫡
Show Your Passion:When writing your application, let your enthusiasm for AI and full-stack engineering shine through. We want to see that you’re genuinely excited about building innovative systems and redefining collaboration in the workplace.
Tailor Your Experience:Make sure to highlight your experience with TypeScript, React, and Node.js. We’re looking for someone who can own product features, so share specific examples of how you've successfully shipped complex production systems in the past.
Be Clear and Concise:Keep your application straightforward and to the point. We appreciate clarity, so avoid jargon and focus on what makes you a great fit for this role. Remember, we’re looking for high-agency individuals who can communicate effectively.
Apply Through Our Website:Don’t forget to submit your application through our website! It’s the best way for us to receive your details and ensures you’re considered for this exciting opportunity to join our founding team.
How to prepare for a job interview at Jack & Jill
✨Know Your Tech Stack Inside Out
Make sure you’re well-versed in TypeScript, React, and Node.js. Brush up on your experience with LLM orchestration and be ready to discuss specific projects where you've shipped complex production systems. This will show that you can hit the ground running.
✨Demonstrate Your Problem-Solving Skills
Prepare to tackle hypothetical scenarios related to agentic systems and real-time collaboration. Think about how you would architect solutions for multi-step LLM pipelines or optimise front-end performance. This will highlight your high-agency mindset and ability to own product features.
✨Showcase Your Collaborative Spirit
Since you’ll be working closely with founders and other team members, be ready to discuss how you’ve successfully collaborated in past roles. Share examples of how you’ve integrated tools like Slack or Notion into your workflows, as this aligns with the company’s focus on enhancing team collaboration.
✨Ask Insightful Questions
Prepare thoughtful questions about the company's vision and the technical challenges they face. This not only shows your genuine interest but also gives you a chance to demonstrate your understanding of the industry and the role's impact on the future of work.
