Fontana AI
Full-time · Flexible hours

Full Stack Engineer

Build Flow — the governed AI platform where operators author AI Agent, design data pipelines, and run deterministic workflows.

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Engineering at Fontana

We build software the AI-native way: agents write, review, and ship alongside humans. On a busy weekend we have spun up 5,000+ development agents. You will design work so fleets of agents can move fast — and so humans stay in the control path for what matters.

Our Slack workspace has more Agents and AI employees than humans. We build for a future where code and contributions flow from many hands, some human, some not.

❌ Does this sound chaotic rather than exciting? This role is not for you.
✅ Sounds like the only sane way to ship in 2026? Keep reading.

What you will be working on

End-to-end product slices

React UI → Convex backend → tests → docs.

Flow UI

Interactive canvas, workflow authoring, data pipeline controls, and real-time product surfaces.

Knowledge Graph

Operational context, lineage, file and skill surfaces, and evidence-aware data modelling.

Agent Harness

Agents, Skills, Tools, MCP connections, Agent Interop, approved model access, and human-in-the-loop controls.

Reactive backend

Real-time Convex queries, mutations, and actions with auth, RBAC, and fail-closed behaviour.

Workflow engine

Deterministic execution, lineage, connectors, and server-side orchestration.

Our Stack

A practical spread across product, data, agents, platform, observability, and compliance evidence.

Flow UI logoFlow UI
React 19 logoReact 19
TypeScript logoTypeScript
Vite logoVite
Tailwind CSS v4 logoTailwind CSS v4
Convex logoConvex
Zitadel logoZitadel
Node workflow engine logoNode workflow engine
Postgres logoPostgres
Vault logoVault
Airbyte logoAirbyte
Docling logoDocling
OpenSandbox logoOpenSandbox
Kubernetes logoKubernetes
AWS logoAWS
Helm logoHelm
Terraform logoTerraform
Traefik logoTraefik
Gatus logoGatus
HyperDX / OTLP logoHyperDX / OTLP
Vitest logoVitest
Playwright logoPlaywright

You'd be a strong fit if you

  • Write strong TypeScript and modern React.
  • Ship full-stack features across UI and typed API/data layers.
  • Are comfortable with reactive / real-time data.
  • Test behaviour that can actually break.
  • Communicate clearly in writing so agents and teammates can continue your work.
  • Already work comfortably with AI-assisted development, agent review loops, and human-controlled shipping.
  • Can operate around DevOps, AWS, Kubernetes, and production systems without drama.
  • Understand why compliance evidence matters: SOC 2, ISO 27001, DORA, audit trails, access control, retention.

Bonus signals

  • Convex, Firebase, or similar reactive backends.
  • Canvas / editor / data-grid product surfaces.
  • Workflow, ETL, or financial-ops tooling.
  • Monorepo discipline and real AuthZ.
  • CRDT principles.
  • Audit trails, fail-closed paths, and evidence — not vibe-based “ship it”.
SOC 2ISO 27001DORAAWSK8s

Location

We will review applications in location rounds, because early collaboration will be easiest with timezone and founder access close to home.

  1. First round: London applicants
  2. Second round: UK applicants
  3. Third round: EU applicants

How we work

Flexible

Flexible hours.

AI-first

Agents and humans ship alongside each other.

Low theatre

Direct access to founders — no ticket theatre, no six-layer approval stack.

We prefer clean architecture over hacks. Specs and docs stay in sync with the code.

Apply

Application form via Notion. If this sounds like the only sane way to ship in 2026, send us your details.

Open application form →