Engineering a Multi-Tenant B2B SaaS

Engineering a Multi-Tenant B2B SaaS from Product to Infrastructure.

Designed and built a production B2B SaaS end-to-end, covering backend architecture, multi-tenancy, infrastructure, security, integrations and mobile expansion.

The project : CoutureCiel is a multi-tenant B2B SaaS platform built for tailoring workshops to manage their customers, measurements, orders, inventory, finances and day-to-day operations.

As the sole engineer and CTO, I designed and built the system across the full engineering lifecycle — from product architecture and data modeling to production infrastructure and operations.

- Designed the multi-tenant application and data architecture - Built core business workflows for orders, measurements, inventory, accounting and customer management - Implemented granular roles, permissions and subscription quota enforcement - Integrated WhatsApp Cloud API and transactional SMS for operational notifications - Designed CI/CD and production deployment workflows - Built and operated the self-hosted infrastructure - Implemented monitoring, incident response and infrastructure cost optimization - Designed a Zero Trust model for sensitive internal administration - Extended the existing platform architecture toward React Native / Expo mobile applications

My role : Architecture • Backend Engineering • DevOps • Infrastructure • Security • Integrations • Technical Product Engineering

Stack : NestJS • Next.js • Docker • Dokploy • Cloudflare • WhatsApp Cloud API