AI Fullstack Software Engineer

About Artifex One

Artifex One is an AI studio based in Barcelona, Spain. We design and ship AI-native products and managed solutions for businesses that want real, measurable ROI from AI, not buzzwords. Our work spans full-stack web applications, LLM integrations, automation pipelines, and vertical SaaS products built for specific industries.

We're a small, lean team where every engineer ships meaningful work. No bureaucracy, no fluff, no make-work.

About the role

We're hiring a Full-Stack AI Developer Intern to work alongside our core engineering team on production AI products. You'll write code that real businesses depend on from day one. Not toy projects, not internal tools no one uses.

This is a remote internship with a clear path to full-time conversion based on performance.

What you'll do

• Build and ship full-stack features in production: backend APIs, database schemas, frontend interfaces, and the glue between them.

• Integrate LLMs into real workflows: prompt design, tool calling, structured outputs, validation, and handling failure modes gracefully.

• Connect our products to third-party APIs (messaging platforms, business systems, payment providers) and own the integration end-to-end.

• Contribute to automation flows that move data and trigger actions across multiple systems.

• Deploy, monitor, and debug services in production. Engineers own what they ship.

• Participate in technical decisions: architecture, library choices, trade-offs. Your input will be heard, even as an intern.

Our stack

• Frontend: Next.js, React, TypeScript, Tailwind

• Backend: Hono on Bun, PostgreSQL, Drizzle ORM

• Infrastructure: Railway, Vercel, Cloudflare R2

You don't need to know every piece of this stack on day one. You should be comfortable picking up new tools fast.

What we're looking for

• 1+ year of hands-on experience with TypeScript and a modern frontend framework (React or Next.js preferred). Bootcamp grads, self-taught builders, and CS students all welcome. What matters is what you've actually shipped.

• Comfort with backend work: REST APIs, relational databases (PostgreSQL preferred), ORMs.

• Genuine curiosity about AI and LLMs. You don't need to be an ML researcher, but you should have played with the OpenAI, Anthropic, or Mistral APIs and have opinions about what works and what doesn't.

• Ability to read API documentation and ship integrations without constant hand-holding.

• Strong written English. You'll coordinate async with a distributed team across India and Europe.

• A portfolio: GitHub, Peerlist projects, side projects, deployed apps. Anything that proves you can actually build.

Nice to have

• Experience with Hono, Bun, or other lightweight Node alternatives.

• Familiarity with Drizzle ORM or similar type-safe ORMs.

• Experience deploying on Railway, Vercel, or Cloudflare.

• Prior internship or freelance experience shipping production code.

• Open-source contributions.

What you'll get

• Real ownership over real production code from week one.

• Direct mentorship from senior engineers.

• Exposure to the full lifecycle of AI products: from prompt engineering to infrastructure to client deployment.

• Flexible async work with weekly syncs.

• Stipend (details discussed during interview).

• Clear path to a full-time offer for strong performers.

Logistics

• 100% remote.

• Initial commitment: 3 months, with intent to extend or convert to full-time.

• Time zone: any (we operate across IST and CET).

• Start date: as soon as possible.