Track This Job
Add this job to your tracking list to:
- Monitor application status and updates
- Change status (Applied, Interview, Offer, etc.)
- Add personal notes and comments
- Set reminders for follow-ups
- Track your entire application journey
Save This Job
Add this job to your saved collection to:
- Access easily from your saved jobs dashboard
- Review job details later without searching again
- Compare with other saved opportunities
- Keep a collection of interesting positions
- Receive notifications about saved jobs before they expire
AI-Powered Job Summary
Get a concise overview of key job requirements, responsibilities, and qualifications in seconds.
Pro Tip: Use this feature to quickly decide if a job matches your skills before reading the full description.
To support our rapid growth and deliver an even better experience to our users, we are hiring a Senior Backend Developer to help build the next generation of features, scale our architecture, and mentor junior developers.
Your Mission
As a Senior Backend Developer, you’ll join a cross-functional squad (Product, Design, Dev) and play a central role in building our core backend services. Reporting to the CPTO, your key mission will be to ensure robustness, scalability, and performance across all backend layers of our SaaS platform.
You’ll be responsible for:
- Designing and implementing scalable APIs and services in Node.js
- Collaborating with Product and Frontend teams to build impactful features
- Ensuring high performance and availability in a multi-tenant SaaS environment
- Participating in architectural decisions and refactors as we scale
- Maintaining best practices in testing, documentation, and security
- Contributing to code reviews and mentoring team members
- Backend: Node.js (NestJS), PostgreSQL, Redis
- Frontend: React (TypeScript)
- DevOps: Azure, Docker, GitHub Actions, Datadog, Sentry
- Tools: Jira, Notion, Figma, Slack
✅ Must-Haves
- 4+ years of experience in backend development, with strong command of Node.js
- Experience with REST APIs, SQL databases (ideally PostgreSQL), and scalable architectures
- Solid understanding of software engineering principles: testing, CI/CD, security, performance
- Experience working in an Agile product environment
- Strong communication and teamwork skills
- Fluent in French, with a high level of English
- Knowledge of multi-tenant SaaS environments
- Experience with NestJS, Azure, or authentication systems (SSO, OIDC…)
- Past experience in a scale-up or fast-paced product company
- Mentorship or technical leadership experience
- Join a collaborative, ambitious, and international team in central Paris
- Work on a high-impact product used daily by thousands of users
- Ownership and autonomy: we trust you to make technical decisions
- Training budget, regular team offsites, and 1–2 days remote/week
- Lunch vouchers, health insurance (Alan), and top-tier equipment
- HR Interview -30 min
- Technical interview – 1 hour
- Live Case + Debrief – 1 hour
- Team Fit – 1 hour
- Final Interview - 1 hour
Key Skills
Ranked by relevanceReady to apply?
Join Witco and take your career to the next level!
Application takes less than 5 minutes