Printify Hub - Printing Shop Billing System

A full-stack billing and invoice management system built for printing and graphic design businesses. Handles quotations, job orders, final invoices, and tracks payments across multiple job types.

GitHub: Printify-Hub-billing

Overview

Print shops deal with diverse, custom-priced jobs — business cards, banners, brochures, t-shirt prints, signage. Each job has different materials, sizes, quantities, and finishes. Standard billing software either doesn't support custom job types or is overly complex for a small print shop owner.

Lanka Print Studio's billing system was built to be simple, fast, and tailored to the printing industry.

Tech Stack

Layer	Technology
Frontend	React 18, React Router
Backend	Node.js, Express
Database	PostgreSQL
ORM	Prisma
PDF Generation	PDFKit
Auth	JWT
Styling	Tailwind CSS

Key Features

🖨️ Job Order Management

Create job orders with custom job types (business cards, banners, flyers, etc.)
Specify dimensions, quantity, material, finish, and unit price
Track job status: Pending → In Progress → Completed → Delivered

💼 Quotation System

Generate quotations before confirming an order
Convert approved quotation → invoice with one click
Email-ready PDF quotation export

🧾 Invoice & Payment

Auto-generate invoice number (LPS-2025-0001 format)
Record advance payments and balance due
Mark invoices as fully paid
Print-ready A4 invoice PDF

📊 Business Reports

Daily job completion summary
Monthly revenue by job type
Outstanding balance report

👥 Customer Management

Customer profiles with purchase history
Track outstanding balances per customer
Search by name, phone, or business name

Architecture

React SPA (Frontend)
│
│  REST API (JSON)
▼
Express.js API Server
├── /auth           Authentication
├── /customers      Customer CRUD
├── /jobs           Job order management
├── /quotations     Quotation flow
├── /invoices       Invoice + PDF export
└── /reports        Business analytics
│
│  Prisma ORM
▼
PostgreSQL Database

Prisma Schema (Key Models)

model Customer {
  id          String     @id @default(uuid())
  name        String
  phone       String?
  email       String?
  business    String?
  jobs        Job[]
  invoices    Invoice[]
  createdAt   DateTime   @default(now())
}

model Job {
  id          String     @id @default(uuid())
  customer    Customer   @relation(fields: [customerId], references: [id])
  customerId  String
  jobType     String     // business_card | banner | flyer | tshirt | other
  description String
  width       Float?
  height      Float?
  unit        String?    // cm | inch | m
  quantity    Int
  material    String?
  finish      String?    // gloss | matte | laminated
  unitPrice   Decimal
  totalPrice  Decimal
  status      JobStatus  @default(PENDING)
  invoice     Invoice?   @relation(fields: [invoiceId], references: [id])
  invoiceId   String?
  createdAt   DateTime   @default(now())
}

model Invoice {
  id            String      @id @default(uuid())
  invoiceNumber String      @unique
  customer      Customer    @relation(fields: [customerId], references: [id])
  customerId    String
  jobs          Job[]
  subtotal      Decimal
  discount      Decimal     @default(0)
  total         Decimal
  paidAmount    Decimal     @default(0)
  status        PayStatus   @default(UNPAID)
  createdAt     DateTime    @default(now())
}

enum JobStatus  { PENDING IN_PROGRESS COMPLETED DELIVERED }
enum PayStatus  { UNPAID PARTIAL PAID }

API Design

# Auth
POST   /auth/login
POST   /auth/refresh

# Customers
GET    /customers?search=lakshmi
POST   /customers
GET    /customers/:id
PUT    /customers/:id

# Jobs
GET    /jobs?status=PENDING&customerId=abc
POST   /jobs
PUT    /jobs/:id
PATCH  /jobs/:id/status    body: { status: "IN_PROGRESS" }

# Invoices
GET    /invoices?status=UNPAID
POST   /invoices            body: { customerId, jobIds[], discount }
GET    /invoices/:id
GET    /invoices/:id/pdf    streams PDF
PATCH  /invoices/:id/payment  body: { amount }

# Reports
GET    /reports/daily?date=2025-03-01
GET    /reports/revenue?from=2025-01-01&to=2025-03-31&groupBy=jobType
GET    /reports/outstanding

PDF Invoice Layout

The PDF invoice includes:

Shop header with logo placeholder, address, and contact
Customer details and invoice number
Job order table with columns: Job Type, Description, Qty, Unit Price, Total
Subtotal, discount, and grand total
Payment status badge
Footer with bank details and "Thank You" message

// Simplified invoice PDF generation
function drawJobTable(doc: PDFKit.PDFDocument, jobs: Job[]) {
  const columns = [
    { label: 'Job Type', width: 120 },
    { label: 'Description', width: 180 },
    { label: 'Qty', width: 50 },
    { label: 'Unit Price', width: 80 },
    { label: 'Total', width: 80 },
  ];

  let y = doc.y;
  columns.forEach((col, i) => {
    const x = 50 + columns.slice(0, i).reduce((s, c) => s + c.width, 0);
    doc.text(col.label, x, y, { width: col.width, align: 'left' });
  });

  jobs.forEach(job => {
    y += 20;
    // Draw each row...
  });
}

Challenges & Solutions

Challenge: Flexible Job Types

Every print shop has different job categories. Hardcoding job types would make the system unusable for different shops.

Solution: Job type is a free-text field on the Job model. The frontend suggests common types from previous entries (via an autocomplete that queries the DB). New types are added organically as the shop creates them.

Challenge: Quotation → Invoice Conversion

Converting a quotation to an invoice without duplicating data or causing inconsistencies.

Solution: Quotations and invoices share the same Invoice model. A isQuotation: boolean flag distinguishes them. On conversion, the flag is flipped and invoiceNumber is assigned — no data migration needed.

What I Learned

Prisma's type-safe query builder dramatically reduces bugs at the data layer
PostgreSQL's DECIMAL type is essential for financial data — never use FLOAT for money
Building for small business owners requires extreme simplicity: fewer clicks, fewer fields, fewer decisions
PDF generation with dynamic tables (page breaks, row overflow) is harder than it looks — good abstraction in the table renderer pays off

Printify Hub - Printing Shop Billing System

A full-stack billing and invoice management system built for printing and graphic design businesses. Handles quotations, job orders, final invoices, and tracks payments across multiple job types.

GitHub: Printify-Hub-billing

Overview

Lanka Print Studio's billing system was built to be simple, fast, and tailored to the printing industry.

Tech Stack

Layer	Technology
Frontend	React 18, React Router
Backend	Node.js, Express
Database	PostgreSQL
ORM	Prisma
PDF Generation	PDFKit
Auth	JWT
Styling	Tailwind CSS

Key Features

🖨️ Job Order Management

Create job orders with custom job types (business cards, banners, flyers, etc.)
Specify dimensions, quantity, material, finish, and unit price
Track job status: Pending → In Progress → Completed → Delivered

💼 Quotation System

Generate quotations before confirming an order
Convert approved quotation → invoice with one click
Email-ready PDF quotation export

🧾 Invoice & Payment

Auto-generate invoice number (LPS-2025-0001 format)
Record advance payments and balance due
Mark invoices as fully paid
Print-ready A4 invoice PDF

📊 Business Reports

Daily job completion summary
Monthly revenue by job type
Outstanding balance report

👥 Customer Management

Customer profiles with purchase history
Track outstanding balances per customer
Search by name, phone, or business name

Architecture

React SPA (Frontend)
│
│  REST API (JSON)
▼
Express.js API Server
├── /auth           Authentication
├── /customers      Customer CRUD
├── /jobs           Job order management
├── /quotations     Quotation flow
├── /invoices       Invoice + PDF export
└── /reports        Business analytics
│
│  Prisma ORM
▼
PostgreSQL Database

Prisma Schema (Key Models)

model Customer {
  id          String     @id @default(uuid())
  name        String
  phone       String?
  email       String?
  business    String?
  jobs        Job[]
  invoices    Invoice[]
  createdAt   DateTime   @default(now())
}

model Job {
  id          String     @id @default(uuid())
  customer    Customer   @relation(fields: [customerId], references: [id])
  customerId  String
  jobType     String     // business_card | banner | flyer | tshirt | other
  description String
  width       Float?
  height      Float?
  unit        String?    // cm | inch | m
  quantity    Int
  material    String?
  finish      String?    // gloss | matte | laminated
  unitPrice   Decimal
  totalPrice  Decimal
  status      JobStatus  @default(PENDING)
  invoice     Invoice?   @relation(fields: [invoiceId], references: [id])
  invoiceId   String?
  createdAt   DateTime   @default(now())
}

model Invoice {
  id            String      @id @default(uuid())
  invoiceNumber String      @unique
  customer      Customer    @relation(fields: [customerId], references: [id])
  customerId    String
  jobs          Job[]
  subtotal      Decimal
  discount      Decimal     @default(0)
  total         Decimal
  paidAmount    Decimal     @default(0)
  status        PayStatus   @default(UNPAID)
  createdAt     DateTime    @default(now())
}

enum JobStatus  { PENDING IN_PROGRESS COMPLETED DELIVERED }
enum PayStatus  { UNPAID PARTIAL PAID }

API Design

# Auth
POST   /auth/login
POST   /auth/refresh

# Customers
GET    /customers?search=lakshmi
POST   /customers
GET    /customers/:id
PUT    /customers/:id

# Jobs
GET    /jobs?status=PENDING&customerId=abc
POST   /jobs
PUT    /jobs/:id
PATCH  /jobs/:id/status    body: { status: "IN_PROGRESS" }

# Invoices
GET    /invoices?status=UNPAID
POST   /invoices            body: { customerId, jobIds[], discount }
GET    /invoices/:id
GET    /invoices/:id/pdf    streams PDF
PATCH  /invoices/:id/payment  body: { amount }

# Reports
GET    /reports/daily?date=2025-03-01
GET    /reports/revenue?from=2025-01-01&to=2025-03-31&groupBy=jobType
GET    /reports/outstanding

PDF Invoice Layout

The PDF invoice includes:

Shop header with logo placeholder, address, and contact
Customer details and invoice number
Job order table with columns: Job Type, Description, Qty, Unit Price, Total
Subtotal, discount, and grand total
Payment status badge
Footer with bank details and "Thank You" message

// Simplified invoice PDF generation
function drawJobTable(doc: PDFKit.PDFDocument, jobs: Job[]) {
  const columns = [
    { label: 'Job Type', width: 120 },
    { label: 'Description', width: 180 },
    { label: 'Qty', width: 50 },
    { label: 'Unit Price', width: 80 },
    { label: 'Total', width: 80 },
  ];

  let y = doc.y;
  columns.forEach((col, i) => {
    const x = 50 + columns.slice(0, i).reduce((s, c) => s + c.width, 0);
    doc.text(col.label, x, y, { width: col.width, align: 'left' });
  });

  jobs.forEach(job => {
    y += 20;
    // Draw each row...
  });
}

Challenges & Solutions

Challenge: Flexible Job Types

Every print shop has different job categories. Hardcoding job types would make the system unusable for different shops.

Challenge: Quotation → Invoice Conversion

Converting a quotation to an invoice without duplicating data or causing inconsistencies.

What I Learned

Prisma's type-safe query builder dramatically reduces bugs at the data layer
PostgreSQL's DECIMAL type is essential for financial data — never use FLOAT for money
Building for small business owners requires extreme simplicity: fewer clicks, fewer fields, fewer decisions
PDF generation with dynamic tables (page breaks, row overflow) is harder than it looks — good abstraction in the table renderer pays off

Kavidu Hasaranga

Printify Hub - Printing Shop Billing System

Overview

Tech Stack

Key Features

🖨️ Job Order Management

💼 Quotation System

🧾 Invoice & Payment

📊 Business Reports

👥 Customer Management

Architecture

Prisma Schema (Key Models)

API Design

PDF Invoice Layout

Challenges & Solutions

Challenge: Flexible Job Types

Challenge: Quotation → Invoice Conversion

What I Learned

Screenshots

Kavidu Hasaranga

Printify Hub - Printing Shop Billing System

Overview

Tech Stack

Key Features

🖨️ Job Order Management

💼 Quotation System

🧾 Invoice & Payment

📊 Business Reports

👥 Customer Management

Architecture

Prisma Schema (Key Models)

API Design

PDF Invoice Layout

Challenges & Solutions

Challenge: Flexible Job Types

Challenge: Quotation → Invoice Conversion

What I Learned

Screenshots