Store — SaaS ERP

Context

Many retailers still run their business on notebooks or spreadsheets: rough stock counts, invisible margins, no traceability. Store set out to deliver an accessible, affordable web and mobile ERP covering the full retail cycle — from restocking to checkout — while staying easy to adopt.

It is a SaaS product: each company gets its own isolated space, can run several stores and employees with distinct roles, and subscribes to a plan. I designed and built the entire backend and the system architecture.

Key modules

• Sales & checkout

  Full order cycle, FIFO stock consumption, instalment payments, anonymous walk-in customers and till summaries.

• Purchasing & suppliers

  Supplier orders from draft to receipt, multiple receptions, traceable batches and split payments.

• Stock & inventory

  Batch tracking with expiry dates, average-cost valuation, movement journal and physical inventories with profit/loss reports.

• SaaS subscriptions

  Plans (Trial, Standard, Pro) with limits, coupons and promotions, manual payment validated against proof (Wave, Orange Money).

• Security & RBAC

  JWT authentication, refresh tokens, data-driven access control: 85+ permissions and roles customisable per company.

• Reporting & audit

  Dashboards (top products, margins, stock valuation) and an audit log whose scope adapts to the user's role.

Challenges & solutions

• Challenge

  Model very different users — an ADMIN running the platform, an owner running their company, employees tied to its stores — each linked to distinct entities, without multiplying authentication or authorization mechanisms.

  Solution

  Separate identity from access. A Person → Utilisateur hierarchy (JOINED inheritance) captures who the user is and what they belong to: the owner carries their company, the employee their store. Facing it, a single Account entity holds the credentials and points to a role bearing permissions. The result: admin, owner and employees all authenticate through the same entry point and are authorized by the same RBAC — every endpoint checks a permission, never the user's concrete type. System roles stay non-delegable, and the resolved scope (company, store) is projected into the JWT for uniform authorization.

• Challenge

  Guarantee that no company can ever see another's data on a shared database.

  Solution

  The tenant (company + store) is carried in the JWT and enforced on every query through the security context. Perimeter scoping is centralised to prevent leaks by omission.

• Challenge

  Know the stock value at any time and trace every unit, including perishable goods.

  Solution

  A FIFO batch stock model (lot number, expiry date, purchase price) with a timestamped movement journal and expiring-batch detection. Valuation uses the average purchase price.

• Challenge

  Offer fine-grained, role-specific permissions without recompiling for every new need.

  Solution

  A data-driven RBAC: permissions and roles live in the database, roles are customisable per company, and each endpoint declares the permission it requires.

• Challenge

  Collect subscriptions while local payments go through Wave, Orange Money or transfer, outside the app.

  Solution

  A manual-payment subscription flow: the customer uploads proof, an admin approves or rejects, and activation is computed (plan, duration, promotion, coupon). The model is ready for an automated gateway when the time comes.

• Challenge

  Keep quality high across a broad scope and keep the database under control.

  Solution

  741 tests run against a real PostgreSQL database, a SonarQube quality gate (≥ 80% coverage on new code), a schema versioned by 49 Flyway migrations, all shipped through a GitLab CI pipeline and a multistage Docker image.

Tech stack