Title:
Senior Fullstack Software Engineer (Python / TypeScript / React)
Location:
Paris (Morning Laffitte, Hybrid — 2 remote days/week)
Language requirement:
French B2+ and English B1+
Salary : 60K - 80K€ + ESOP
Contract:
Full-time, CDI
About Symbiotic Security
Symbiotic Security is a cybersecurity startup based in Paris, building an
AI-powered assistant
that helps developers write secure code.
Integrated directly into IDEs and CI/CD pipelines, our solution detects and fixes vulnerabilities, including those generated by tools like GitHub Copilot.
We combine
deep cybersecurity expertise
,
modern engineering practices
, and
cutting-edge AI
to help developers build safer software, faster.
Founded in
2024
16 team members
across Paris and New York
Strong engineering \& product culture
Modern offices at
Morning Laffitte (Paris 9th)
We’re now expanding our tech team with a senior fullstack engineer who thrives in a collaborative and high-autonomy environment.
Role Overview
You will work on both backend (≈70%) and frontend (≈30%), contributing to our SaaS platform and internal tools. You will collaborate closely with:
Abir
— Engineering Manager
Minh Thang
— Tech Lead
Édouard
— CTO
This role has significant ownership, technical depth, and the opportunity to shape a fast-growing product from early stages.
Your Responsibilities
Develop and maintain backend services and APIs (Python, Django).
Build and improve frontend features (React, TypeScript).
Contribute to our
hexagonal architecture
and
DDD
approach.
Work on diverse topics: REST APIs, CLI tools, AI agents, monitoring.
Improve performance, reliability, and code quality.
Lead code reviews, testing strategies, and release processes.
Mentor teammates and contribute to engineering best practices.
Collaborate with product, design, and cybersecurity teams.
What We’re Looking For
Required
5+ years of professional experience in software engineering
Strong experience with
Python
(Django \= strong plus)
Strong experience with
React
/
TypeScript
Solid SQL knowledge (PostgreSQL preferred)
Experience working in high-quality engineering environments
Ability to work and communicate in
English (B2+) and French (B2+)
Comfortable using LLMs (ChatGPT, Copilot, Claude)
Nice-to-Haves
Experience with DDD or hexagonal architecture
Experience with monitoring / logging / performance work
Interest in cybersecurity (not required)
Mindset
Curious and rigorous
Autonomous and impact-driven
Low ego, collaborative, strong communicator
Product-oriented, eager to build meaningful software
Tech Stack at Symbiotic
Backend:
Python 3.12+, Django, REST API
Frontend:
TypeScript, React SPA
Database:
PostgreSQL
Infra:
AWS, Docker, Terraform
Tooling:
Sentry, observability, internal analytics
Testing:
94% backend coverage
Why Join Us
€60–80K depending on experience
ESOP
100% health insurance
Swile meal card
RTT + paid vacation
€500 equipment budget
2 remote days/week
Collaborative, no-ego engineering team
Deep-tech product with real impact
Fast hiring process ( 2 weeks)
Hiring Process
Intro call with Blanche (Talent Acquisition) — 30 min
Interview with Abir (Engineering Manager) — 45 min
On-site technical test — 2h
Culture fit + team lunch — 2h
Offer