Senior Software Engineer

Fullstack Software Engineer (Python / TypeScript / React) Paris (Morning Laffitte) | Full-time | 2 remote days per week Tech Team | Role split 70% backend / 30% frontend About Symbiotic Security Symbiotic Security is a cybersecurity startup helping developers write secure code through an AI-powered assistant integrated into their IDE and CI/CD pipelines. Our solution has two unique strengths: it provides developers with interactive training to understand vulnerabilities as they code, and it automatically detects and remediates security flaws introduced by generative AI tools such as GitHub Copilot.➡️ Founded in April 2024➡️ 16 team members split between Paris (Tech team) and New York (Sales team) ➡️ Goal: 15 new hires by the end of 2026 Our offices are located at Morning Laffitte (Paris 9ᵗʰ) — bright open spaces with collaborative areas, a friendly atmosphere, and a focus on productivity. Tech Stack & Environment • Backend: Python 3.12+ / Django (monolith, REST API) • Frontend: TypeScript / React (SPA) for the frontend of the SaaS platform, • Typescript for the IDE plugin • Database: PostgreSQL • Architecture: Monolithic - Hexagonal, DDD being introduced • Tests: 94% backend coverage, 100% business logic covered • Tools: Sentry, logs, traces, internal analytics • Satellite services: CLI tools & AI agents written in Python Your Mission • Contribute to both the backend (70%) and frontend (30%) of our SaaS product. • Participate in the design and evolution of our hexagonal architecture and DDD approach. • Collaborate closely with Abir (Engineering Manager), Minh Thang (Tech lead) and Édouard (CTO) on technical and product decisions. • Work on diverse projects: REST APIs, CLI tools, AI agents, performance optimization. • Lead continuous improvement initiatives, such as code reviews, automated testing, and release management. • Offer technical guidance to team members, fostering a culture of learning and professional development. What We’re Looking For Core Skills • Master's degree in Computer Science or related field. • Proven experience (min 5 years) as a software engineer, with a strong track record of designing and delivering complex software systems, Python and TypeScript required ✅ • Demonstrated expertise in backend development using Python. An experience of Django would be a strong plus. • Demonstrated expertise in frontend development using Typescript / React. • Solid SQL knowledge (PostgreSQL preferred) Appreciated • Experience working with Product Manager, Product Designer, or UI/UX person. • Strong grasp of clean code principles (SOLID, DRY, YAGNI) • Understanding or curiosity for DDD • Monitoring / logging / API optimization = big plus • Comfortable using LLMs (ChatGPT, Copilot, Claude) Soft Skills & Mindset • Early-stage startup mindset: autonomous, fast, impact-driven • Curious, rigorous, and eager to understand before acting • Strong communicator, collaborative, no ego • Capable of challenging ideas and defending opinions constructively • Product-oriented with a desire to build meaningful software • Work-life balance valued What You’ll Have Achieved Timeframe Key Milestones 3 months First features shipped, ramp-up on the stack, contribution to testing pipeline 6 months Leading a technical scope, improving architecture, driving performance or monitoring initiatives 12 months Recognized internal expert / coach within the team Methodology & Culture • Agile-ish organization (2-week sprints, continuous releases) • Systematic code reviews • Occasional pair programming • Mix of maintenance, new features, and R&D work • Monthly “Bug Day” (stress testing the product) • “Cool down period” planned for internal tech projects AI culture: every developer is encouraged to use ChatGPT, Copilot, or Claude as part of their workflow. Team Our product team brings together diverse profiles working collaboratively: fullstack engineers, AI engineers, cybersecurity experts, product managers, and product designers: all coming from different backgrounds. • ‍ MT – Lead Engineer • ‍ Abir – Engineering Manager • ‍ Édouard – CTO Team culture: • Collaboration > hierarchy • Technically demanding but kind environment • No-ego culture • Strong product–tech alignment Compensation & Benefits BSPCE (equity) available 100% health insurance coverage️ Swile meal card €500 equipment budget Allowance for Sustainable Commuting (e.g., cycling, carpooling, public transport)️ RTT + paid vacation 2 remote days per week Important opportunities for career advancement and professional development by being a pioneer within a new company.‍ Strong product & engineering culture in the company. Vibrant and inclusive company culture with regular team outings and events.☝ Chance to make a meaningful impact and shape the future of Symbiotic. Referral bonus: €2,000 Hiring Process We respect your time and will make it quick and efficient. All of that will be completed within two weeks. • Call with our Talent Acquisition - Blanche - 30 minutes • Meeting with our Engineering Manager - Abir - 45 minutes to 1 hour. • On-site technical test with our tech lead - Minh Thang - 1,5 hour. • Culture fit - Meeting with the CTO and lunch with the team - 2 hours • Formal hiring proposal.