At a Glance
- Tasks: Build innovative AI-driven applications and collaborate with customers to create impactful solutions.
- Company: Exciting stealth-mode AI startup at the forefront of technology.
- Benefits: Competitive salary, equity options, and a dynamic work environment.
- Other info: Fast-paced culture that encourages creativity and ownership in every project.
- Why this job: Join a revolutionary team shaping the future of software with cutting-edge AI technologies.
- Qualifications: 1-3 years of experience in TypeScript and React, with a passion for product development.
The predicted salary is between 55000 - 95000 £ per year.
Stealth‑mode AI infrastructure startup building the agentic knowledge layer for research.
You will build the search primitive for the AI era, developing a stack designed for how agents actually work. As a full‑stack owner, you will ship end‑to‑end product surfaces from customer dashboards to agent runtimes. This role combines first‑principles research with hard engineering to make massive knowledge accessible to LLM‑driven workflows.
Location: London, UK
Why this role is remarkable:
- Ship at the frontier of information retrieval during a total industry renaissance where LLMs are changing the fundamental way software is built.
- Join a high‑velocity, engineering‑led environment where you have total ownership of product design, ML integration, and deployment cycles.
- Work in an "in‑office" culture that values being "cracked," moving fast, and building magical user experiences that don't exist anywhere else.
Responsibilities:
- Own the full stack end‑to‑end, utilizing AWS, GCP, Next.js, Supabase, Clerk, and Vercel to ship high‑quality features rapidly.
- Build and integrate AI‑native interfaces and agent runtimes, making LLM-driven workflows a first‑class primitive of the product.
- Collaborate directly with customers in forward‑deployed settings to translate complex research and financial service needs into technical product reality.
Qualifications:
- A product‑minded engineer with 1‑3 years of experience shipping real‑world applications using TypeScript and modern React.
- A resourceful generalist who can design APIs, model data, write migrations, and reach into ML as a first‑principles problem solver.
- Fluent with AI engineering tools like Claude Code and Codex to multiply output while maintaining an exceptional bar for UX and design taste.
Full Stack Engineer (£55k–£95k + Equity) at Stealth-mode AI infrastructure startup in London employer: Jack & Jill
Join a pioneering AI infrastructure startup in London, where you will be at the forefront of transforming information retrieval. Our dynamic work culture fosters innovation and speed, allowing you to take full ownership of your projects while collaborating closely with customers to create unparalleled user experiences. With competitive salaries, equity options, and a commitment to employee growth, we offer a unique opportunity to thrive in a fast-paced environment that values creativity and technical excellence.
StudySmarter Expert Advice🤫
We think this is how you could land Full Stack Engineer (£55k–£95k + Equity) at Stealth-mode AI infrastructure startup in London
✨Join Local Tech Meetups
Get out there and mingle with fellow developers by joining local tech meetups. It’s a fantastic way to meet people who might be working at Jack & Jill or know someone who does. Plus, you can pick up some trendy tech skills and trends while you're at it!
✨Contribute to Open Source Projects
Show off your coding chops by jumping into open-source projects. Not only does this give you practical experience, but it also gets you noticed in the dev community. You'll create a killer portfolio that speaks volumes about your skills to Jack & Jill.
✨Tap into Online Developer Communities
Don’t underestimate the power of online developer communities like GitHub, Stack Overflow, and even Reddit. Participate in discussions, share your projects, and build your visibility. We can often find opportunities through these channels that can lead to a full-time gig at companies like Jack & Jill.
✨Explore Job Boards Specifically for Tech Roles
Keep your eyes peeled on job boards that focus on tech roles. Sites like TechCareers or Stack Overflow Jobs can often have listings for companies like Jack & Jill that might not show up on broader job sites. Make it a habit to check these regularly, and don’t hesitate to apply directly through our website!
We think you need these skills to ace Full Stack Engineer (£55k–£95k + Equity) at Stealth-mode AI infrastructure startup in London
Some tips for your application 🫡
Show off your coding skills:When applying for a software engineering role, it's super important to showcase your coding skills. Make sure your CV includes your tech stack, any relevant programming languages you’re comfortable with, and examples of projects you've worked on. If you have a GitHub profile, link it up! We love to see code in action.
Tailor your portfolio:For a full-time role, we’d expect to see some solid examples of your work in your portfolio. Make sure to include at least two or three projects that highlight your problem-solving skills and your ability to work with different technologies. Focus on the projects that are most relevant to the position at Jack & Jill.
Craft a killer cover letter:Your cover letter is your chance to stand out—make it personal! Explain why you want to work at Jack & Jill and how your skills align with the role. Show us your passion for software development. We dig enthusiastic candidates who understand the value of collaboration and continuous learning!
Be clear and concise:When it comes to writing your CV and cover letter, clarity is key. Avoid jargon that could confuse us and stick to simple, direct language. Highlight your achievements with quantifiable results where possible, and keep everything easy to read. A well-organised application goes a long way!
How to prepare for a job interview at Jack & Jill
✨Brush Up on Your Coding Skills
For a full-time software engineering role, it's crucial that we stay sharp with our coding abilities. Expect technical questions that might involve solving problems on the spot or discussing algorithms. Practise on platforms like LeetCode or HackerRank to get comfortable with the types of questions that often come up.
✨Know Your Tools and Frameworks
Make sure we’re well-acquainted with the tools and technologies listed in the job description. Familiarise ourselves with any specific frameworks or programming languages mentioned. If Jack & Jill uses React or Node.js, for instance, be ready to discuss how we’ve used them in previous projects or coursework.
✨Showcase Your Projects
Bring along a portfolio that highlights our best work. This could be code samples, GitHub repositories, or any side projects we’ve built. Make sure we can talk through our thought process for each project, especially the challenges we faced and how we solved them—this shows our problem-solving skills in action.
✨Prepare for Behavioural Questions
While technical skills are key, full-time positions also require cultural fit. Be ready to discuss our previous experiences and how we handle teamwork, conflict, and deadlines. Brush up on the STAR method—Situation, Task, Action, Result—to clearly articulate our past experiences when discussing how we've contributed to a team.
