Why API Design Matters for Business Software
Your API is the contract between your system and every other system it connects to. A poorly designed API creates integration headaches for years. A well-designed API becomes a business asset that enables growth.
According to Postman's 2025 State of the API report, 89% of developers say API quality directly impacts their ability to deliver projects on time.
Naming and URL Structure
Use Nouns, Not Verbs
✗ GET /getProperties
✗ POST /createTenant
✓ GET /properties
✓ POST /tenantsBuilding something similar?
See how we approach business software development.
The HTTP method IS the verb. The URL is the noun.
Use Plural Nouns for Collections
✓ GET /properties — List all properties
✓ GET /properties/123 — Get property 123
✓ POST /properties — Create a property
✓ PATCH /properties/123 — Update property 123
✓ DELETE /properties/123 — Delete property 123Nest Resources Logically
✓ GET /properties/123/units — Units for property 123
✓ GET /properties/123/units/456 — Unit 456 in property 123
✓ GET /tenants/789/leases — Leases for tenant 789
✗ GET /getUnitsForProperty?id=123 — Avoid query-style URLs for resource hierarchiesUse Proper HTTP Methods
| Method | Purpose | Idempotent | Safe |
|---|---|---|---|
| GET | Read | Yes | Yes |
| POST | Create | No | No |
| PUT | Full replace | Yes | No |
| PATCH | Partial update | No | No |
| DELETE | Delete | Yes | No |
Response Format Standards
Always Return Consistent Structure
// Success response
{
"data": { ... },
"meta": {
"total": 142,
"page": 1,
"perPage": 20
}
}
// Error response
{
"error": {
"code": "VALIDATION_ERROR",
"message": "Email address is required",
"details": [
{ "field": "email", "message": "Required" }
]
}
}Use Proper HTTP Status Codes
200 — Success (GET, PATCH, PUT)
201 — Created (POST)
204 — No Content (DELETE)
400 — Bad Request (validation error)
401 — Unauthorized (not logged in)
403 — Forbidden (logged in but no permission)
404 — Not Found
409 — Conflict (duplicate resource)
422 — Unprocessable Entity (semantic validation error)
429 — Too Many Requests (rate limited)
500 — Internal Server ErrorPagination
Never return unbounded lists. Always paginate:
GET /properties?page=1&perPage=20&sort=createdAt&order=desc
Response:
{
"data": [ ... ],
"meta": {
"total": 142,
"page": 1,
"perPage": 20,
"totalPages": 8,
"hasNext": true,
"hasPrev": false
}
}Authentication and Security
Use Bearer Tokens
Authorization: Bearer eyJhbGciOiJIUzI1NiIs...Rate Limiting
Always implement rate limiting to protect your API:
Response headers:
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87
X-RateLimit-Reset: 1640000000Input Validation
Never trust client data. Validate everything server-side:
// Validate at the API boundary, not just in the UI
const createPropertySchema = z.object({
name: z.string().min(1).max(200),
address: z.string().min(1),
units: z.number().int().min(1),
type: z.enum(['residential', 'commercial', 'mixed']),
});Versioning
Version your API from day one:
✓ /api/v1/properties
✓ /api/v2/properties (when you need breaking changes)
✗ /properties (no version = breaking changes break all clients)TIP
Key Takeaways
- URLs are nouns (plural), HTTP methods are verbs
- Always return consistent response structure with data/meta or error
- Use proper HTTP status codes — not just 200 and 500
- Always paginate list endpoints
- Implement auth, rate limiting, and input validation from day one
- Version your API if external consumers will use it
