Founding, Full Stack Engineer (React.js & Python)

Syntera; Amsterdam; On-site; EUR 60,000 - 80,000; Full time

Job summary

A YC AI Scale-up in Amsterdam is seeking a Full Stack Engineer with expertise in React.js, TypeScript, and Python. This on-site role involves developing core product features and collaborating closely with the team to drive innovation. Candidates should have 3+ years of experience in full-stack development and be fluent in English. This position offers a unique opportunity to contribute significantly to an early-stage startup.

Qualifications

• 3+ years of experience in full‑stack development, preferably as a Senior Software Engineer.
• Proven knowledge of TypeScript, React, and server-side development.
• Experience designing multi-tenancy SaaS products.

Responsibilities

• Develop core product features on both the frontend and backend.
• Collaborate with founders and customers for new features.
• Maintain and improve the codebase's performance.

Skills

Full-stack development

React.js

TypeScript

Server-side development

SaaS product design

Fluent English

Tools

Cursor

Windsurf

Claude

IntelliJ

Junie

Job description

Full Stack Engineer (React.js, TypeScript, Python) – YC AI Scale-up – Amsterdam, NL

Experience: 3+ years – React.js, TypeScript, Python
Employment type: Full‑Time

Job Overview

Our client develops AI sales employees for Europe. Their first product is an AI SDR that owns the entire outbound process – from researching relevant companies to executing campaigns on email, LinkedIn, and via letters. We are seeking a highly skilled and proactive founding software engineer to join our YC‑backed startup full‑time and in person in Amsterdam. This is a fantastic opportunity to make a substantial impact in a fast‑paced, early‑stage startup environment.

Responsibilities

• Own and develop core product features on both the frontend and backend.
• Collaborate with founders and customers to conceptualise, design and implement new features.
• Maintain and improve the codebase for optimal performance.
• Conduct code reviews and perform debugging tasks.

Required Qualifications

• Proven track record in full‑stack development, preferably as a Senior Software Engineer.
• Comprehensive knowledge of TypeScript, React, and server‑side development (preferably Remix).
• Proficiency in designing multi‑tenancy SaaS products.
• Experience leveraging latest AI code IDEs (Cursor, Windsurf, Claude, IntelliJ, Junie).
• Experience operating software in a scalable manner.
• Fluent in English; able to communicate complex technical concepts clearly and effectively.

Bonus Skills and Experience

• Proficiency in Python.
• Experience hosting applications on Azure.

Application

Submit a copy of your CV directly to this advertisement or email [e-mail]. This role is actively interviewing and can be offered within 7‑10 days.

Location

Amsterdam, North Holland, Netherlands – On‑site role.