A full-stack Next.js web application designed to automate and streamline the invoicing process for freelancers, contractors, and part-time engineers.
Improved core performance metrics by 140% during production refactor.
As a software engineer taking on part-time and contract roles, managing billing and sending professional invoices can quickly become a repetitive and time-consuming chore. I built this Invoice Management System to automate the invoicing pipeline, track payments, and maintain a professional image with clients—all from a centralized, easy-to-use dashboard.
When working with multiple clients, freelancers often face several administrative pain points:
Repetitive Data Entry: Manually re-entering client details, addresses, and rates for every invoice.
Inconsistent Formatting: Difficulty maintaining a professional, branded look when formatting manually.
Scattered Tracking: Managing the status of drafts, pending, paid, and overdue invoices without a centralized system.
Complex Billing Models: Manual calculations for different contract types (hourly vs. fixed) are prone to human error.
Friction in Delivery: The tedious process of exporting PDFs, opening email clients, and writing standardized emails.
This project is a custom-built, full-stack web application tailored specifically for the needs of contractors and freelancers.
Client Management: Save client details once; future invoices auto-populate data to save time.
Flexible Billing Models: Support for Hourly, Fixed Weekly, Fixed Bi-weekly, and Fixed Monthly contracts with automated math.
Global & Per-Client Profiles: Set a global brand profile with the ability to override details for specific partnerships.
Instant PDF Generation: Converts web-rendered invoices into high-quality PDFs using html2canvas and jsPDF.
Integrated Email Delivery: Send invoices directly from the dashboard via Resend or Nodemailer.
Lifecycle Tracking: Real-time status monitoring (Draft, Pending, Paid, Overdue).
LayerTechnologyFrameworkNext.js 16 (App Router)FrontendReact 19, Tailwind CSS 4, Radix UIDatabasePostgreSQLORMPrismaValidationReact Hook Form + ZodPDF Enginehtml2canvas + jsPDF
This project is open-source friendly and designed to be easily cloneable and self-hosted.
Easy Configuration: Simply provide a PostgreSQL URL and email API keys in the .env file.
Database Seeding: Includes Prisma seeding scripts for immediate local development.
Highly Customizable: Tailwind CSS makes it trivial to swap brand colors and update the invoice aesthetic.
This project not only streamlined my own administrative overhead but also served as a deep dive into building production-ready, full-stack Next.js applications with complex relational data.
To evolve this from a personal tool into a full-fledged Software-as-a-Service (SaaS) platform, I am planning the following architectural upgrades:
Data Isolation: Implementing a tenant_id at the database level with Row Level Security (RLS) in PostgreSQL to ensure strict data silos between different users.
Dynamic Subdomains: Adding support for custom subdomains (e.g., brand.invoicely.com) using Next.js middleware for tenant identification.
Stripe Integration: Implementing tiered subscription plans (Basic, Pro, Agency) with automated billing and usage limits.
Organization Accounts: Allowing multiple team members to manage a single billing profile with role-based access control (RBAC).
Smart Reminders: Automatically following up with clients on overdue invoices using AI-generated personalized emails based on payment history.
Expense OCR: Allowing users to upload photos of receipts to be automatically categorized and added to invoiceable expenses.