Software Engineer — Full-Stack, AI-native

The role

Essential curates small teams of world-class engineers to accelerate our clients' innovation cycles. For this role you will join a production AI companion: users talk to an AI avatar via video, voice, or text, powered by a self-hosted LLM stack, Supabase, Stripe billing, a React/TypeScript frontend, and an iOS app with OTA updates.

Own tickets end-to-end across the frontend, edge functions, database, and LLM pipeline — using AI agents as your primary implementation force multiplier — and raise the quality and speed of the whole team's agent workflow.

The one non-negotiable: you build with AI agents

AI agents are a first-class part of our workflow. We are not looking for “uses autocomplete”. We are looking for someone who:

• Delegates whole units of work to agents — a ticket, a refactor, an investigation — and scopes, briefs, and constrains them so the output is right the first time more often than not.
• Reviews agent output like a senior reviewer — catches hallucinated APIs, silent scope creep, dropped edge cases, and knows when the agent is confidently wrong.
• Builds the harness, not just the prompt — maintains agent rules and skills, MCP tooling, and deterministic checks that make agent output verifiable.
• Runs agents in parallel and asynchronously, orchestrated rather than babysat.
• Knows the limits — why an LLM must never be the sole merge gate, and where humans stay the decision-makers on safety-critical paths.

What you will do

• Deliver tickets across the stack: React/TypeScript UI, Supabase edge functions (Deno), Postgres migrations and RLS policies.
• Work on the LLM request path: streaming SSE handlers, prompt/context assembly, RAG retrieval, guard-model integration, provider routing and latency work.
• Integrate and maintain third-party services for video avatars, voice, Stripe billing, and iOS OTA delivery.
• Own entitlement and token correctness — code paths where silent bugs cost money or lock users out.
• Ship most work through agents: brief, run, review, iterate. Maintain and extend the agent rules and skills so output converges on team conventions.
• Keep CI, deploy workflows, and regression runs green; investigate failures using logs, traces, and DB queries.

Must-have

• 4+ years of professional software engineering, with strong TypeScript on both frontend (React) and backend (Node/Deno or equivalent).
• Demonstrable, day-to-day use of AI coding agents (Cursor agents, Claude Code, Codex, or similar) for complete tasks — you will be asked to show this live.
• Solid PostgreSQL: schema design, migrations, RLS or equivalent authorization models.
• Experience with streaming / real-time systems (SSE, WebSockets, WebRTC, or audio/video pipelines).
• Production LLM integration experience and a grounded view of non-determinism.
• Comfortable with Git-based ticket flows, code review, CI/CD (GitHub Actions), and writing tests where they matter.
• Fluent written English; German is a plus (the product's primary locale is DE).

Nice-to-have

• Supabase, Stripe billing, Capacitor / iOS OTA pipelines.
• Self-hosting LLMs (vLLM, guard models), RAG/embeddings, Playwright.
• Prior work in health or other regulated / safety-critical domains.

How we assess

We assess AI-agent skills hands-on: a live delegated task using your own tooling, a review of an agent-produced PR with planted flaws, and a conversation about the harnesses you have built.