AI Scientist
Remote • UK, London
Full Time
Build with ownership. Ship with speed
We do not hire often. Fewer than one in one hundred and thirty applicants make it through. But the ones who do tell us the same thing: this is the team they have been looking for.
At Seven Sigma, you will build AI-powered products from the ground up, not just implement models. You will architect intelligent systems, ship to production, and see your work transform how real users interact with technology. You will get technical feedback from top-tier engineers. You will be trusted, coached, and pushed. And you will be part of a small team that takes the work seriously and each other even more seriously.
This is not just a job. It is a place for builders who want to operate at their edge.
The AI Engineer We're Looking For
We are not looking for an AI scientist or pure ML researcher. We need an engineer who lives and breathes the practical application of AI.
You are:
- An engineer first who happens to be obsessed with AI's real-world potential
- Current with the entire AI ecosystem: LLMs, RAG systems, AI agents, vector databases, prompt engineering, and the latest API releases
- Someone who can go from "here's a new model" to "here's a production system" without hand-holding
- Experienced in building with OpenAI, Anthropic, Gemini, and open-source models
- Comfortable implementing everything from simple ChatGPT integrations to complex agentic workflows
- Able to evaluate trade-offs between different AI approaches (when to use RAG vs fine-tuning vs prompt engineering)
- Pragmatic about AI - you know when to use it and when not to
Beyond the technical:
- Write clean, scalable code and care about the why as much as the what
- Stay up to date with new AI releases because you're genuinely excited about them (you probably already tried the latest model before we ask about it)
- Think in systems and love the challenge of making AI work reliably at scale
- Have side projects showcasing creative AI applications
- Value clear communication and fast iteration over tickets and process
- Want to be part of a small team where your ideas actually shape what gets built
We also care deeply about who you are. We look for character. Humility. Curiosity. The ability to give and receive direct feedback. People who would rather be told the truth than be made to feel comfortable.
We reference a well-known SAS principle: You need to be excellent, but you also need to be someone the team would trust with their lives. We do not take that lightly.
What You Will DO
- Design and build production AI systems that solve real problems
- Implement RAG pipelines, multi-agent systems, and LLM-powered features
- Optimize for cost, latency, and accuracy across different AI services
- Create robust evaluation frameworks for AI performance
- Own the entire AI stack from prompt design to production deployment
- Work closely with design and product to identify where AI creates real value
- Make architectural decisions about when and how to leverage AI
- Stay ahead of the curve on new models, techniques, and best practices
- Build internal tools and abstractions to accelerate AI development
- Move fast, iterate daily, and write code that handles the unpredictability of AI gracefully
TECH STACK
We use the right tools for the right job. Our AI engineering stack includes:
AI/ML Core:
- LangChain, LlamaIndex for orchestration
- OpenAI, Anthropic Claude, Google Gemini APIs
- Hugging Face transformers and inference
- Vector databases (Pinecone, Weaviate, Qdrant)
- VAPI for voice AI
- Custom evaluation and monitoring tools
Engineering Foundation:
- Python (FastAPI) for AI services
- TypeScript, React, Next.js for AI-powered interfaces
- PostgreSQL with pgvector
- Vercel, Railway, AWS for deployment
- Real-time streaming for AI responses
Dev and Product Tooling:
- Weights & Biases, LangSmith for AI observability
- PostHog for product analytics
- Stripe, Clerk, SendGrid for core infrastructure
What We OFFER
- Top-of-market compensation and performance-based bonuses
- Real ownership of AI products from idea to production
- Direct access to the latest AI tools and APIs (no budget constraints on experimentation)
- One-on-one coaching and technical mentorship
- Fast-moving projects at the cutting edge of AI application
- Deep involvement with senior engineers and founders
- Remote-first team with flexibility and autonomy
- A culture of honest feedback and constant growth
- Investment in your personal and professional development
- The chance to shape how a growing company leverages AI