Senior Software Engineer - Python (Django) / Typescript (React) - CDI

About Symbiotic Security

Symbiotic Security is an AI-native cybersecurity startup. We’ve built the first security assistant that lives where developers work: in the IDE and CI/CD pipelines. We don’t just find bugs; we remediate AI-generated flaws and provide real-time coaching to developers.

• The Scale: 25 team members across Paris & NYC.
• The Growth: Aiming for 6 new strategic hires by the end of 2026.
• The Culture: High technical standards, no-ego, and a product-driven mindset.

The Role

Join our Paris-based tech team as a Senior Fullstack Engineer. You will play a key role in evolving our SaaS platform, working closely with our CTO (Édouard), EM (Abir), and Tech Lead (Minh Thang).

• Focus: 70% Backend (Python/Django) | 30% Frontend (React/TypeScript).
• Architecture: We are scaling a monolithic architecture using Hexagonal Architecture and DDD principles.
• Impact: You won't just ship features; you'll lead technical scopes, drive performance initiatives, and mentor peers.

Technical Stack

• Backend: Python 3.12+, Django (REST API).
• Frontend: TypeScript, React (SaaS platform & IDE plugin).
• Quality: 94% backend test coverage (100% on business logic).
• Tools: PostgreSQL, AWS, Sentry, CLI tools, and AI agents.

Who You Are

• Experience: 5+ years of software engineering, with a track record of delivering complex systems.
• Mastery: Strong expertise in Python and TypeScript. Django experience is a major plus.
• Craftsmanship: Deep understanding of SOLID, DRY, and Clean Code. Curiosity for DDD is essential.
• Mindset: Early-stage startup spirit—autonomous, fast, and impact-driven. You understand the "Why" before the "How."

Why Join Symbiotic?

• Elite Tech Culture: Monthly "Bug Days," "cool-down" periods for internal tech projects, and systematic code reviews.
• AI-First: Every developer is encouraged to use LLMs (Copilot, Claude, ChatGPT) in their workflow.
• Package: Competitive base salary + BSPCE (Equity) + 100% Health Cover.
• Environment: Bright offices at Morning Laffitte (Paris 9e), 2 remote days/week, and a vibrant team culture.

Fast-Track Hiring (2 Weeks Max)

• Screening: Call with our Talent Acquisition, Blanche (30 min).
• Manager Interview: Meeting with our EM, Abir (1h).
• Technical: On-site test with our Tech Lead, Minh Thang (1.5h).
• Culture Fit: Meeting with the CTO and lunch with the team.