Fullstack Engineer in Paris

About Arlequin

Arlequin is building the sovereign European alternative to Palantir: an AI platform capable of processing massive data volumes without bias, with high-impact use cases such as fighting disinformation. Founded in late 2024 by Hugo Micheron (researcher in geopolitics and systemic risk) and Antoine Jardin (CNRS research engineer).

~30 people, post-seed, Series A in progress. On-site in Paris.

The role

You’ll join a team of around ten people to contribute to both sides of the platform — ingestion pipelines and data processing on the backend, exploration and analysis interfaces on the frontend. Our product (HUDEX) enables non-technical analysts to interpret narrative dynamics across large-scale digital ecosystems. You’ll work alongside senior engineers who mentor you on architecture, and you’ll quickly take ownership of complete features from end to end.

Stack

• Frontend: React 19, TypeScript, Tanstack Router + Query, Vanilla Extract CSS

• Backend: Hono, Node 24, Drizzle ORM, PostgreSQL, OpenAuth

• Build & infra: monorepo npm workspaces + Turbo, Vite, Docker, Azure Container Registry

• Data : Python

• Tests & quality: Jest, ESLint, Prettier, strict TypeScript

What we’re looking for

• 1–5 years of fullstack experience

• Strong command of TypeScript and a modern React ecosystem

• Comfortable with a Node backend and ORM (Drizzle, Prisma or equivalent)

• A desire to understand architectural choices, not just execute

• Professional English

Bonus

• Already comfortable in a startup environment

• Mastery of agentic coding tools and code models

• Exposure to Python / AI

• Experience with harness coding / implementation

• Interest in emerging tools and paradigms

• Fast learning on TypeScript codebases

Process (~2 weeks)

1. Screening (15 min)

2. Fit interview (30 min)

3. Technical interview (1h)

4. Founder culture fit (45 min)

5. Reference calls

6. Offer

Package

• 50-75k€ + BSPCE

• On-site central Paris

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