Join as the second engineer on a technical co-founder trajectory, owning the end-to-end architecture of our multi-agent AI platform. You will build and scale AWS serverless infrastructure and React interfaces already serving six paid pilots at multi-billion dollar PE firms. This role demands high architectural judgment to lead the 0→1 development of enterprise-grade AI.
Founding Full Stack Engineer (Architect) at Team Theory
Private equity manages over $10 trillion globally, but talent decisions—the biggest lever for returns—are still stuck in the fax-machine era. Team Theory is changing that. As our Founding Full Stack Engineer, you’ll join a $1.2M seed-stage startup already live with six paid pilots at major PE firms. You aren't just coding; you're the architect of a vertical AI platform embedding elite talent science into automated workflows. If you’re a senior engineer ready for a technical co-founder trajectory and want to own everything from AWS infra to LangGraph orchestration, this is your 0→1 moment.
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Location
Brussels, Belgium
Compensation
Not Disclosed
Company
Team Theory
Role overview
Team Theory is an AI-powered talent intelligence platform designed for private equity and venture capital firms to deploy consistent, world-class hiring methodology across portfolio companies. The platform generates PE-quality hiring artifacts such as executive scorecards, interview loops, and candidate reports that traditionally required $50K consulting fees. It codifies proven executive assessment science developed by former leaders from ghSMART, Bain & Company, and Palantir, enabling portfolio-wide hiring infrastructure that reduces mis-hires by 60-80% and cuts recruiting costs by $400K-$1M+ annually. The platform provides AI-guided questions, structured interview processes, data-driven decision-making tools, and organizational memory to help talent leaders make faster, smarter hiring decisions across their portfolios.
What you will do
- Architect and build the core Team Theory platform using React, AWS serverless (Lambda, S3, Postgres), and Infrastructure as Code.
- Implement sophisticated LangGraph multi-agent orchestration and RAG pipelines to automate complex talent science workflows for PE clients.
- Own the entire production lifecycle, from designing secure multi-tenant data isolation layers to deploying feature gates and organizing the monorepo.
Who this is a fit for
- Proven senior experience building 0→1 products end-to-end, with deep expertise in React, TypeScript, and AWS serverless architectures.
- Strong architectural judgment with the ability to manage complex codebases, infrastructure, and security posture without needing heavy process or approval chains.
- Hands-on experience or significant capability in GenAI development, specifically multi-agent LLM applications, embeddings, and vector search pipelines.
Why this role is remarkable
- Join a seed-stage startup with immediate market validation, including 6 paid pilots with private equity firms managing over $40B in assets.
- Step into a technical co-founder trajectory, working directly with founders to set the engineering culture and architectural standards from the ground up.
- Tackle high-stakes technical challenges in vertical AI, building a platform that handles sensitive data for the world’s most elite financial institutions.
How Jack & Jill work together
I get to know what you’re great at, then find roles you’d never find yourself.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.
I recruit from Jack’s network and make the intro when I spot a great match.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.
Jack gets to know what you're great at and what you want next, then searches 15 million jobs daily and helps you discover roles at companies like this.
Meet Jack
What happens next?
Jack’s an AI agent for job searching and career coaching. He works for you.
Jill is the AI recruiter working for the company. She recruits from Jack’s network.
If your profile’s a match and Team Theory wants to meet, Jill will make the intro. In the meantime, Jack will send you excellent alternatives.