Delta Labs uses AI to simulate and predict consumer behaviour at scale. We build Elaiia, a simulation engine that generates AI Twins — intelligent synthetic agents that mirror real consumer populations. Our clients use Elaiia to simulate customer decisions before committing to them: pricing strategies, product launches, campaign messaging, channel allocation. We replace surveys, focus groups, and intuition with simulation-based evidence.

We're a small, focused team and we intend to stay that way. We give people ownership, trust, and the autonomy to do their best work. We work with urgency and intellectual honesty and expect new team members to match our pace. We seek individuals who are curious, rigorous, and want their work to have demonstrable impact. If you're drawn to the idea of a small team building something that hasn't existed before, let's build together.

ABOUT THE ROLE

As a Full Stack Developer at Delta Labs, you will design and build the systems that power Elaiia's simulation platform. The Engineering team owns the full stack, from database schema to production UI, and is responsible for making Elaiia fast, reliable, and scalable.

THE STACK

A modern TypeScript frontend stack built on Next.js and React, backed by PostgreSQL and a set of Python microservices. Long-running study workflows are orchestrated as durable background jobs. OpenAI, Anthropic and Google Gemini are deeply integrated into the product layer, with LangGraph agents and full LLM tracing and evals. Deployed on Vercel and Microsoft Azure.

RESPONSIBILITIES

Design and build production features across the full stack, from data model to UI
Integrate LLM APIs into production workflows: prompt pipelines, structured outputs, token optimization, and reliability at scale
Build and operate long-running, multi-step simulation workflows — durable jobs that run for minutes or hours and cannot silently fail
Treat LLM quality as measurable: tracing, evals, and regression checks on the AI paths you own
Own entire features end-to‑end and take responsibility for their performance, quality, and correctness
Collaborate with the research team to transition experimental AI capabilities — statistical persona models, agent architectures — into production‑grade systems
Improve and extend the platform architecture as simulation workloads grow in complexity and volume
Ship continuously to maintain the pace the company needs

YOU MAY BE A FIT IF

You have 4+ years of experience shipping production web applications in TypeScript
You are strong in the modern React/Next.js ecosystem, and care about code quality, performance, and maintainability
You are comfortable reading and writing Python, or ready to — a meaningful part of our backend is Python services
You have designed relational database schemas that hold up under real-world scale and complexity
You have worked with or are deeply curious about LLM integration — prompt engineering, structured outputs, retrieval‑augmented generation, agent architectures
You use AI tools as a core part of your development workflow and consider AI‑assisted engineering the standard, not optional
You are comfortable working with ambiguity and incomplete specifications
You communicate clearly about technical trade‑offs and write useful documentation

STRONG CANDIDATES MAY ALSO

Have built AI‑powered features used by real customers in production
Have shipped LLM features with real evaluation and observability behind them, not just prompts that looked good in review
Have built asynchronous, long-running job pipelines and know how they fail
Have worked on multi‑tenant including enterprise SSO
Have worked across both Vercel and cloud infrastructure like Azure
Have worked in a high‑velocity early‑stage environment

LOCATION

This role is based in Switzerland. We work from Zürich and meet regularly in person. Candidates should be based in Switzerland or open to relocation.

BENEFITS

We offer a competitive salary, potential equity participation, and the opportunity to build a company from its earliest stages. Delta Labs is an equal opportunity employer. We welcome applications from all backgrounds

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Full Stack Developer

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See also