Senior TypeScript Fullstack Engineer — Remote & AI Tools

CryptoNext Security; Paris; Hybride; EUR 85 000 - 120 000; Plein temps

Résumé du poste

CryptoNext Security, a Paris-based deeptech startup focused on post-quantum cryptography, seeks a senior full-stack engineer to own features end-to-end. You will work across TypeScript, Node.js, React, PostgreSQL, and OpenAPI, collaborating with Product and QA in a hybrid Paris team.

This role emphasizes production-ready testing and architectural decision-making, with AI coding tools as an aid. Join a 6-engineer team within a 15-person R&D group; three days in the Paris office, and remote for

Qualifications

• Strong TypeScript across the stack with strict mode and shared types.
• Node.js backend: API design, auth, errors, observability.
• Asynchronous processing, queues, retries and backpressure.
• PostgreSQL schema design, migrations, indexes, query plans.
• Strong React with hooks and client/server state management.
• Frontend toolchain: fast bundling, utility-first styling, component libs.
• API contract design: REST and OpenAPI, typed clients.
• Unit and integration testing with clear guidance on what to test.
• Experience with AI-assisted development and responsible tooling.
• Senior candidate can justify choices and costs over time.

Responsabilités

• Own features end to end in TS: API, DB, UI.
• Design HTTP APIs consumed via typed RPC client with OpenAPI specs.
• Model and query PostgreSQL; manage migrations and performance.
• Build interfaces with Vite, TanStack, Tailwind, and shadcn/ui.
• Collaborate with Product and QA; write tests and automate.
• Review code and use AI coding tools judiciously.
• Propose upgrades and explain trade-offs and costs.

Connaissances

TypeScript

Node.js

React

PostgreSQL

OpenAPI

REST APIs

Testing

Code review

AI in coding

Senior reasoning

Outils

Hono

OpenAPI

TanStack

Tailwind

Vite

shadcn/ui

PostgreSQL tooling

Description du poste

CryptoNext Security, a Paris-based deeptech startup focused on post-quantum cryptography, seeks a senior full-stack engineer to own features end-to-end. You will work across TypeScript, Node.js, React, PostgreSQL, and OpenAPI, collaborating with Product and QA in a hybrid Paris team.

This role emphasizes production-ready testing and architectural decision-making, with AI coding tools as an aid. Join a 6-engineer team within a 15-person R&D group; three days in the Paris office, and remote for