What is the difference between PUT and PATCH?

PUT replaces an entire resource with the payload you send, so omitted fields may be cleared. PATCH applies a partial update, modifying only the fields you include. Use PUT when sending a complete representation and PATCH when changing a subset. PUT is idempotent; well-designed PATCH can be too.

Can an API work without authentication?

Yes. Public APIs serving non-sensitive data — like weather or public stats — may allow anonymous access. However, any endpoint exposing private data or mutating state must authenticate and authorize requests. Even public APIs typically use API keys for rate limiting, usage tracking, and abuse prevention.

Should I use GraphQL or REST for my project?

Use REST for straightforward, resource-oriented CRUD where HTTP caching matters and simplicity wins. Choose GraphQL when clients need flexible, nested data and you want to avoid maintaining many endpoints. GraphQL reduces over-fetching but adds caching and query-complexity challenges. Many teams successfully use both, picking per use case.

How do I secure a REST API?

Enforce HTTPS everywhere, authenticate and authorize every endpoint, and check resource ownership per request. Validate all input, apply rate limiting, and return generic error messages. Follow the OWASP API Security Top 10, use short-lived tokens with least-privilege scopes, and never expose stack traces or internal details to clients.

How to Design Better APIs

This is a practical, up-to-date guide to Design Better APIs — what it is, why it matters in 2026, and how to apply it in real projects. It is written for developers and founders who want clear answers and proven best practices, not filler.

Whether you're just starting out or leveling up, treat this as a working reference you can return to. Every section is built to be skimmed, applied, and shared.

GraphQL vs REST: Which Should You Choose?

REST exposes many endpoints, each returning a fixed shape. GraphQL exposes one endpoint and a strongly typed schema, letting clients ask for exactly the fields they need in a single request. This eliminates the over-fetching and under-fetching common in REST.

Tradeoffs to weigh:

GraphQL excels when clients need flexible, nested data and you want to avoid endpoint sprawl; it adds query-complexity and caching challenges.
REST shines for simple, resource-oriented CRUD, leverages HTTP caching natively, and is universally understood.

GraphQL shifts work to the client and requires guarding against expensive queries. REST relies on the server to define useful response shapes. Many teams run both, choosing per use case rather than treating it as all-or-nothing.

Why Should You Document APIs With OpenAPI?

An API is only as useful as it is understandable. The OpenAPI Specification provides a language-agnostic, machine-readable format for describing endpoints, parameters, request and response schemas, and authentication. Version 3.1 aligns fully with JSON Schema, improving validation fidelity.

A single OpenAPI document powers an entire toolchain:

Interactive docs via Swagger UI or Redoc
Client SDK generation in many languages
Server stubs and mock servers for parallel development
Automated contract testing to catch breaking changes

Writing the spec first — design-first development — forces clarity about the contract before any code exists, surfacing inconsistencies early. Even when generated from code, keeping an accurate spec means consumers, QA, and partners all work from the same source of truth.

What Is the Difference Between Authentication and Authorization?

These terms are often conflated but solve different problems. Authentication answers "who are you?" — verifying identity through credentials, tokens, or keys. Authorization answers "what are you allowed to do?" — deciding whether an authenticated identity may access a specific resource or action.

A request can authenticate successfully yet still be denied. For example, a logged-in user (authenticated) trying to delete another user's account should be rejected (not authorized). Practical guidance:

Handle authentication once, early in the request lifecycle
Enforce authorization at the object level, per request, near the data
Use scopes, roles, or policies to express permissions explicitly

The most common and damaging API flaw — broken object-level authorization — happens when developers authenticate but forget to verify ownership of the requested resource.

How Does REST API Architecture Work?

REST (Representational State Transfer) is an architectural style built on HTTP. It models everything as resources addressed by URLs, manipulated with standard verbs. A GET /users/42 retrieves a user; DELETE /users/42 removes one. Responses use HTTP status codes to signal outcomes.

Key constraints make an API truly RESTful:

Statelessness: each request carries all context the server needs
Uniform interface: consistent, predictable resource naming
Client-server separation: the UI and data store evolve independently
Cacheability: responses declare whether they can be cached

Statelessness is the most consequential: because servers store no session between calls, REST APIs scale horizontally with ease. Design resources around nouns, not verbs, and let HTTP methods express the action.

Why Does API Versioning Matter?

APIs are contracts, and breaking that contract breaks every client depending on it. Versioning lets you evolve an API — removing fields, changing response shapes, renaming resources — without forcing all consumers to upgrade simultaneously.

Common strategies, each with tradeoffs:

URI versioning (/v1/users): explicit, cache-friendly, but couples version to the path
Header versioning (Accept: application/vnd.api.v2+json): keeps URLs clean but is less discoverable
Query parameter (?version=2): simple but easy to omit

Whatever you choose, treat additive changes (new optional fields) as non-breaking and reserve version bumps for genuinely incompatible changes. Communicate deprecation timelines clearly and keep old versions running long enough for clients to migrate safely.

What Are the Most Important API Security Best Practices?

API security starts with the OWASP API Security Top 10, whose 2023 edition ranks broken object-level authorization and broken authentication as the leading risks. Most breaches stem from missing access checks, not exotic exploits.

Foundational controls every API needs:

Enforce HTTPS/TLS for all traffic — no plaintext exceptions
Apply authentication and authorization on every endpoint, checking object ownership
Validate and sanitize all input to block injection
Implement rate limiting to blunt brute-force and denial-of-service attempts
Return generic errors that avoid leaking stack traces or internals

Apply the principle of least privilege to tokens and scopes. Security is layered: assume any single control can fail and ensure another catches the gap.

Design Better APIs: Key Facts and Data

According to recent industry research and the official documentation linked below:

GraphQL was publicly released by Facebook (Meta) in 2015 after internal use since 2012
The OpenAPI Specification reached version 3.1.0, aligning fully with JSON Schema
Postman's State of the API reports surveyed over 40,000 developers worldwide

Quick-Reference Summary

A map of what this guide covers:

Topic	What you'll learn
GraphQL vs REST: Which Should You Choose?	REST exposes many endpoints, each returning a fixed shape.
Why Should You Document APIs With OpenAPI?	An API is only as useful as it is understandable.
What Is the Difference Between Authentication and Authorization?	These terms are often conflated but solve different problems.
How Does REST API Architecture Work?	REST (Representational State Transfer) is an architectural style built on HTTP.
Why Does API Versioning Matter?	APIs are contracts, and breaking that contract breaks every client depending on it.
What Are the Most Important API Security Best Practices?	API security starts with the OWASP API Security Top 10

How to Get Started with Design Better APIs

A simple path that works:

Learn the fundamentals of Design Better APIs from primary sources, not just tutorials.
Build one small, real project end to end.
Get feedback, refactor, and add tests.
Ship it publicly and document what you learned.
Repeat with a slightly harder project each time.

Build It with a World-Class Full Stack Developer

Sandeep Kumar Chaudhary is a full stack world-class developer. If you want to turn this into a real, production-ready product, get in touch — message directly on WhatsApp at +9779802348957 for a fast, no-pressure consult.

You can also explore the projects already shipped to thousands of users, or start a conversation here.

Final Thoughts

Authentication proves who you are; authorization decides what you can do — treat them as separate concerns. The developers and teams who win in 2026 pair strong fundamentals with consistent shipping. Start small, stay curious, build in public, and revisit this guide as your skills grow.