Senior TypeScript Fullstack Engineer — Hybrid (Remote/Paris)

CryptoNext Security SAS; Paris; Hybrid; EUR 70,000 - 110,000; Full time

Benefits offered by this job

Hybrid work model

Paris office three days a week

Exposure to post-quantum cryptography

Job summary

CryptoNext Security SAS in Paris is hiring a senior Software Engineer to own features end-to-end across the stack, from TypeScript back-end to React front-end. You will work in a small team, ship secure, production-grade services, and collaborate with Product and QA.

You’ll design APIs, optimize PostgreSQL schemas, and apply AI-assisted development responsibly. Join a deeptech startup building post-quantum cryptography solutions for finance, defense, and telecoms.

Qualifications

• Experience shipping production-grade TypeScript services.
• Strong knowledge of API design and OpenAPI specs.
• Familiarity with PostgreSQL schema design and migrations.
• Experience with modern frontend tooling and React architecture.

Responsibilities

• Own features end-to-end in TypeScript on the stack (backend and frontend).
• Design HTTP APIs consumed via OpenAPI specs and typed RPC clients.
• Model and query PostgreSQL with schema, migrations, and indexing.
• Build interfaces with Vite, TanStack, Tailwind, and shadcn/ui.
• Write unit and integration tests and ensure QA can automate coverage.
• Review code and guide teammates on best practices.

Skills

TypeScript

Node.js

React

PostgreSQL

API design

Testing

Code review

AI-assisted development

Tools

Hono

OpenAPI

Vite

TanStack

Tailwind

shadcn/ui

Job description

CryptoNext Security SAS in Paris is hiring a senior Software Engineer to own features end-to-end across the stack, from TypeScript back-end to React front-end. You will work in a small team, ship secure, production-grade services, and collaborate with Product and QA.

You’ll design APIs, optimize PostgreSQL schemas, and apply AI-assisted development responsibly. Join a deeptech startup building post-quantum cryptography solutions for finance, defense, and telecoms.