Qureos Mentor

Jack & Jill

<div>
 
 This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers.
 
 
 
 She will pick the best candidates from Jack's network.
 
 
 The next step is to speak to Jack.
 
 
 
 Job Title
 
 
 
 Senior Backend Software Engineer
 
 
 
 Salary
 
 
 
 &pound;100k&ndash;&pound;140k + Equity
 
 
 
 Company Description
 
 
 
 Fleek is a ~$50M Series B startup backed by a16z and Y Combinator, building the AI-native infrastructure for the $350B global secondhand fashion market.
 
 
 
 Job Description
 
 
 
 You will join the Growth squad to own the core ecommerce journey, building backend systems for discovery, payments, and seller tools. Reporting to the CTO, you'll integrate the proprietary FleekSort AI classification engine into a marketplace handling millions of items. This role is about digitizing a broken, manual supply chain at global scale.
 
 
 
 Location
 
 
 
 London, UK
 
 
 
 Why this role is remarkable
 
 
 
 <ul>
 <li>
 Work on a genuinely novel technical challenge by integrating FleekSort, a custom AI model (not a GPT wrapper) that digitizes opaque secondhand inventory.
 </li>
 <li>
 Join a hyper-growth company tripling year-on-year with ~$50M in funding from top-tier investors like a16z, Y Combinator, and HV Capital.
 </li>
 <li>
 Deliver massive environmental impact by building systems that have already saved 9 million items from landfills and are scaling to serve thousands of global retailers.
 
 
 </li>
 </ul>
 
 What You Will Do
 
 
 
 <ul>
 <li>
 Architect and own the end-to-end ecommerce journey, including item discovery, search, multi-currency payment systems, and credit infrastructure.
 </li>
 <li>
 Design and scale backend services to handle over 1 million unique items per month, connecting AI grading engines to real-time marketplace workflows.
 </li>
 <li>
 Collaborate in a senior product squad to translate complex international logistics and supply chain challenges into reliable, high-performance software.
 
 
 </li>
 </ul>
 
 The ideal candidate
 
 
 
 <ul>
 <li>
 Has 6-10 years of professional backend experience, ideally using Node.js and TypeScript, with a proven track record of shipping high-traffic production systems.
 </li>
 <li>
 Possesses a product engineering mindset from a consumer-facing marketplace or fintech background, focusing on commercial outcomes rather than just infrastructure.
 </li>
 <li>
 Thrives in early-stage, fast-paced environments (Seed to Series B) and utilizes AI tools like Cursor or Copilot as a force multiplier in their workflow.
 
 
 </li>
 </ul>
 
 Who are Jack &amp; Jill?
 
 
 
 Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
 
 
 And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.
 
 
 
 How does this work?
 
 
 
 <ul>
 <li>
 Jack's an AI agent for job searching and career coaching. He works for you.
 </li>
 <li>
 Jill is the AI recruiter working for the company. She recruits from Jack's network.
 </li>
 <li>
 If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives.
 
 
 </li>
 </ul>
 
 We never post fake jobs
 
 
 
 This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network.
 
 
 Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description.
 
 
 We appreciate this can make them look a bit suspect, but there isn't much we can do about it.
 
 
 Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.
 
 
</div>

Senior Backend Software Engineer (£100k–£140k + Equity) at Fleek

<div>
 
 This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers.
 
 
 
 She will pick the best candidates from Jack's network.
 
 
 The next step is to speak to Jack.
 
 
 
 Job Title
 
 
 
 AI Engineer
 
 
 
 Salary
 
 
 
 Not Disclosed
 
 
 
 Company Description
 
 
 
 StackOne is a $24M VC-funded AI Integration Gateway backed by GV and Workday Ventures. They provide builders of SaaS platforms and AI Agents with a unified toolkit to orchestrate hundreds of enterprise-grade integrations, combining a real-time architecture with 25,000 pre-mapped actions across 200 connectors.
 
 
 
 Job Description
 
 
 
 As an AI Engineer at StackOne, you will build the future of agentic integrations by delivering end-to-end AI products. Reporting to the CTO, you'll work with AI researchers to develop specialized LLMs for tool-calling, ensuring precision and reliability in agentic execution while maintaining high-performance inference pipelines and retrieval systems.
 
 
 
 Location
 
 
 
 London, UK
 
 
 
 Why this role is remarkable
 
 
 
 <ul>
 <li>
 Work at the frontier of AI R&amp;D, building specialized LLMs designed for tool-calling and agentic execution rather than just general-purpose applications.
 </li>
 <li>
 Join a high-growth startup backed by elite investors like GV and Workday Ventures, scaling a platform that already powers thousands of integrations.
 </li>
 <li>
 Collaborate with a world-class veteran engineering team from industry leaders like Google, Microsoft, and Coinbase in a culture built on shipping and ownership.
 
 
 </li>
 </ul>
 
 What You Will Do
 
 
 
 <ul>
 <li>
 Design and deploy full-stack features including inference pipelines, embeddings, and retrieval systems across AWS and Cloudflare.
 </li>
 <li>
 Implement cutting-edge tool-calling and Model Context Protocol (MCP) patterns to enable one-click agent integrations with any tool.
 </li>
 <li>
 Develop and maintain high-quality open-source and internal TypeScript and Python packages to accelerate the developer ecosystem.
 
 
 </li>
 </ul>
 
 The ideal candidate
 
 
 
 <ul>
 <li>
 Professional experience shipping production-grade applications using Generative AI and LLMs like GPT or Anthropic.
 </li>
 <li>
 Expert proficiency in TypeScript and Python with a proven track record of building scalable systems on AWS, GCP, or Cloudflare.
 </li>
 <li>
 Strong background in full-stack engineering with experience publishing SDKs, CLIs, or complex packages in a fast-paced environment.
 
 
 </li>
 </ul>
 
 Who are Jack &amp; Jill?
 
 
 
 Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
 
 
 And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.
 
 
 
 How does this work?
 
 
 
 <ul>
 <li>
 Jack's an AI agent for job searching and career coaching. He works for you.
 </li>
 <li>
 Jill is the AI recruiter working for the company. She recruits from Jack's network.
 </li>
 <li>
 If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives.
 
 
 </li>
 </ul>
 
 We never post fake jobs
 
 
 
 This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network.
 
 
 Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description.
 
 
 We appreciate this can make them look a bit suspect, but there isn't much we can do about it.
 
 
 Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.
 
 
</div>

AI Engineer at StackOne

Join Jack & Jill and explore 2   exciting career opportunities. They're hiring for various roles with options for remote or on-site work. Apply today and become part of their innovative team.

Jack & Jill

About Company

Senior Backend Software Engineer (£100k–£140k + Equity) at Fleek

AI Engineer at StackOne