Why Address Data Matters

Address data is the backbone of e-commerce, logistics, and any location-based service. Poor address quality leads to failed deliveries, lost customers, and wasted money.

The Business Impact

Consider these statistics:

• 2-5% of addresses entered online contain errors
• $20+ average cost to reroute or return a misdelivered package
• 28% of failed deliveries are due to incorrect addresses
• $197 billion lost annually to failed deliveries globally

Common Address Problems

1. Missing Information

1BAD:  123 Main St, New York
2GOOD: 123 Main St, New York, NY 10001, USA

2. Typos and Misspellings

1BAD:  123 Main Stret, New Yrok, NY 10001
2GOOD: 123 Main Street, New York, NY 10001

3. Invalid Postal Codes

1BAD:  123 Main St, New York, NY 99999  (ZIP doesn't exist)
2GOOD: 123 Main St, New York, NY 10001

4. Wrong City/State/ZIP Combination

1BAD:  123 Main St, Los Angeles, NY 10001  (LA isn't in NY)
2GOOD: 123 Main St, New York, NY 10001

5. International Format Confusion

1BAD:  Friedrichstraße 123, Berlin 10117  (wrong order)
2GOOD: Friedrichstraße 123, 10117 Berlin  (German format)

Who Needs Address Processing?

What You'll Build in This Course

By the end of this course, you'll have built:

1. Address Parser - Extract components from raw address strings
2. Postal Code Validator - Validate codes against GeoNames database
3. Address Normalizer - Standardize formats for consistent storage
4. Address Verifier - Check deliverability using geocoding
5. Autocomplete Service - Real-time address suggestions
6. Deduplication Tool - Find and merge duplicate addresses
7. International Formatter - Display addresses by local conventions

The Address Data Pipeline

1Raw Input → Parse → Validate → Normalize → Verify → Store
2                ↓         ↓          ↓
3           Components  Errors   Suggestions

Each step builds on the previous:

1. Parse: Break "123 Main St, NYC, NY 10001" into structured fields
2. Validate: Check if postal code format is correct
3. Normalize: Convert "Street" to "ST", uppercase state codes
4. Verify: Confirm the address actually exists

Free APIs We'll Use

This course uses free, open-source APIs:

No paid services required. You'll learn patterns that work with any provider.

Prerequisites

To get the most from this course, you should be comfortable with:

• JavaScript ES6+ (async/await, classes, modules)
• Node.js basics (npm, file system)
• REST APIs (fetch, JSON)
• Regular expressions (basic patterns)

What's Next

In the next section, we'll explore the global address landscape - how addresses differ across countries and why this matters for your applications.