Overview

Shelfer is a web and mobile platform that enables small businesses to manage inventory, track sales, monitor agent activity, and generate receipts in real time from a single system.

Designed and built as a scalable, multi-tenant SaaS platform for real-world business operations.

Problem

Many small and medium-sized businesses in Ghana rely on manual record-keeping or fragmented tools for inventory and sales management. This leads to stock inaccuracies, poor sales visibility, and delayed reporting. Shelfer was built to centralise these operations into a reliable, easy-to-use platform accessible on both web and mobile.

My Role

I am the sole engineer behind Shelfer, responsible for the entire product lifecycle, including:

• Product architecture and system design

• Web application development

• Backend API design and implementation

• Mobile application development

• Database modeling and performance considerations

Core Features

• Responsive web application for inventory management, sales tracking, and receipt generation.
• Mobile application for field agents to log sales and activity in real time.
• Role-based access control for business owners and agents.
• Real-time data synchronisation between web and mobile clients.
• Reusable UI component system to support rapid future development.

Products page showing a business’s registered inventory.

Technical Stack

Web

• Next.js - Server-rendered frontend and dashboard UI.
• TypeScript - Type safety and maintainable application logic.
• Tailwind CSS - Rapid, consistent UI styling.

Backend

• Node.js - Backend runtime
• Express - RESTful API design and routing
• Clerk - Authentication, and real-time services
• AWS - Media storage

Mobile

• Flutter - Cross-platform mobile application for agents

Database

• PostgreSQL - Relational data modeling for inventory, sales, and business entities

Tooling

• GitHub - Version control and collaboration
• Lighthouse - Performance and accessibility audits

Agent mobile dashboard showing activity and sales access.

Architecture Overview

Shelfer is designed as a multi-tenant system with a clear separation between client applications and backend services. Backend APIs are structured to enforce business rules and ensure data consistency across tenants, with the frontend acting as a thin client layer for interaction.

• Frontend (Web): Next.js dashboard for business owners
• Mobile (Flutter): Agent-facing app for field operations
• Backend API: Node.js + Express handling business logic and data access
• Database: PostgreSQL for structured relational data
• Realtime Layer: Clerk used for authentication and real-time updates

The system supports multiple businesses (tenants), each with isolated data for inventory, sales, and users.

Key Technical Decisions

Multi-tenant Architecture

Designed the system to support multiple businesses within a single deployment, ensuring data isolation per tenant while maintaining a unified codebase.

PostgreSQL for Relational Data

PostgreSQL was selected to model structured relationships between businesses, inventory, sales, and agents, enabling efficient querying and data consistency.

Flutter for Agent Mobile App

Selected Flutter to enable rapid cross-platform development while maintaining a consistent UI and performance across Android devices commonly used by field agents.

Component-driven UI System

Built a reusable UI component system to standardise design across web and mobile, reducing duplication and improving development speed.

A generated receipt after a successful agent sale.

System Highlights

• Handles multi-entity relationships (businesses, agents, inventory, transactions)
• Supports real-time updates across distributed clients (web + mobile)
• Implements role-based access control for different user types
• Designed for scalability across multiple businesses
• Optimised for low-bandwidth and low-performance devices

Challenges & Learnings

• Balancing feature velocity with maintainable architecture as a solo engineer
• Designing a flexible data model that supports inventory, sales, and agent workflows without over-complication
• Ensuring acceptable performance on mobile devices with limited hardware resources
• Managing full-stack ownership across web, backend, and mobile simultaneously

Outcome / Status

Shelfer is under active development, with both web and mobile applications nearing feature completeness. The platform is designed to scale across multiple businesses and provides real-time operational visibility for owners and field agents.

Future Improvements

• Offline-first support for agents in low-connectivity areas
• Advanced analytics and reporting dashboards
• Payment integrations for transaction tracking
• Role expansion for multi-level business management

Private demo available on request.