API Design Complete Beginner Blueprint: REST to Production

Most developers write code that calls APIs every single day. But ask them to do proper API design from scratch and a familiar silence follows. Where do you even start? How do you name endpoints properly? How do you handle errors without confusing the people calling your API? How do you make something that still works cleanly six months later when the requirements change?

These are not exotic questions. They are the exact things that come up in system design interviews, in team code reviews, and in real engineering work. And they are exactly what ScaleDojo's API Design track is built to help you practice.

This guide is a complete beginner blueprint that takes you from not knowing what REST means all the way to understanding what production-ready API design actually looks like. It is written for people who are new to this topic and want a clear, honest walkthrough rather than a list of jargon they have to decode themselves.

Image: A developer looking at a diagram of API endpoints on a whiteboard, showing GET, POST, PUT, and DELETE routes connected to a central server Alt text: A developer planning API endpoint structure on a whiteboard with REST methods and route paths written clearly.

What Is an API and Why Does Design Matter?

API stands for Application Programmable Interface, we can understand meaning of each word as follows:

• Application → Set of a software programs(Amazon, Google, Uber)

• Programming → Software communicate using code(Programming Language )

• Interface → A medium through two things got intract.

An API, or Application Programming Interface provides a way to make communication between the two pieces of software. When your phone's weather app shows you the forecast, it is calling an API run by a weather data service. When you log into a website using your Google account, that login process goes through an API. When an e-commerce checkout page submits your order, an API sends that data to the backend and returns a confirmation.

Why Do We Need APIs?
Imagine you have a mobile app and a database.

Mobile App  -----------------> Database

Can the mobile app directly connect to the database?
Technically, yes—but in real applications, it should never do that.

Because:
   01. Anyone could modify or delete data.
   02. Database credentials would have to be exposed.
   03. Every client would need to understand the database structure.
   04. Changing the database schema could break all clients.

Instead, we place an API in between.
               Mobile App
                   │
                   ▼
                  API
                   │
                   ▼
                Backend
                   │
                   ▼
                Database
Now the client never talks to the database directly. It only talks to the API.
                  

A well-designed API, on the other hand, is a pleasure to use. It is predictable. It does what you expect. When something goes wrong, it tells you clearly what happened and what you can do about it. It handles scale gracefully and changes over time without breaking the people who depend on it.

Learning to design APIs well is not about memorizing rules. It is about developing the thinking and judgment to make good decisions under real constraints. That is exactly the kind of skill ScaleDojo's 50 API design levels are built to develop through hands-on practice and AI-powered feedback. improve overall quality of content and you can add and remove any content to increase engagement.

API Lifecycle:

Planning --> Design --> Development --> Testing --> Deployment --> Monitoring --> Versioning & Maintenance --> Retirement

• Planning → Planning is about deciding what APIs are needed and why.

• Design → Decide how it should look.

• Development → Now developers start implementing the API.

• Testing → Before releasing the API, it must be tested.

• Deployment → Once testing is complete, the API is deployed to a server where clients can access it.

• Monitoring → Once users start using the API, developers monitor it continuously.

• Versioning & Maintenance → Applications change over time. New features are added old features become obsolete.

• Retirement → Retiring the outdated APIs.

Part I: Understanding REST Before You Design Anything

The Problem Before REST: Imagine you're building an e-commerce website. You need APIs for: Users, Products, Orders, Payments, Reviews Without any design principles, developers might create APIs like this:

GET /getAllUsers
POST /createUser
POST /deleteUser
POST /updateUser
GET /fetchProducts
POST /placeOrder

Another team might write:

POST /users/get
POST /users/remove
POST /users/edit

Another team:

POST /userAction?action=delete

All these APIs work, but they are:

• Inconsistent

• Difficult to understand

• Hard to maintain

• Not predictable

As applications became larger, everyone realized there should be a standard way to design APIs.That's where REST comes in.

REST stands for Representational State Transfer. It is not a programming language, framework, or tool. Instead, it is an architectural style a set of design principles and constraints used for creating web services that allow different systems to communicate over the internet.

The core idea behind REST is simple. Your API is built around resources. A resource is anything your system deals with as a distinct thing. In a blog platform, resources might be posts, authors, comments, and tags. In a food delivery app, resources might be restaurants, menus, orders, and drivers.

Each resource has its own URL, which is called an endpoint. The way you interact with a resource is determined by the HTTP method you use. Core HTTP Methods:

• GET (Read)

  • Purpose: Retrieve data from the server.

  • Typical Success Code: 200 OK

• POST (Create)

  • Purpose: Send data to the server to create a new resource.

  • Behavior: Neither safe nor idempotent (calling it twice creates two resources).

  • Typical Success Code: 201 Created

• GET (Update/Replace)

  • Purpose: Replace an entire existing resource with new data, or create it if it doesn't exist.

  • Typical Success Code: 200 OK or 204 No Content

• PATCH (Partial Update)

  • Purpose: Modify only specific fields of an existing resource instead of replacing the whole thing.

  • Typical Success Code: 200 OK or 204 No Content

• DELETE (Remove)

  • Purpose: Permanently delete a resource from the server.

  • Typical Success Code: 204 No Content or 200 OK

These five methods, applied to clear resource-based URLs, are the foundation of REST. Most of what confuses beginners about API design comes from not having a firm grasp of these basics, so it is worth slowing down here before moving on.

Image: A simple diagram showing the five HTTP methods, GET, POST, PUT, PATCH, and DELETE, each mapped to a plain English description of what they do Alt text: Diagram of HTTP methods GET POST PUT PATCH and DELETE with plain English descriptions of each method's purpose.

Part II: Naming Your Endpoints Well

Let’s first understand what is Endpoint, while learning APIs, you'll often hear people say:

• "Create a new endpoint."

• "This endpoint returns all users."

• "Call the login endpoint."

But what exactly is an endpoint? The simple definition id endpoint is “a specific URL (or URI path) where a client sends an HTTP request to interact with a resource or perform an operation“. Let’s understanding with an example, suppose your API is hosted at:

https://api.example.com

Now your API provides these paths:

/users
/products
/orders

The complete URLs become:

https://api.example.com/users
https://api.example.com/products
https://api.example.com/orders

Each of these is an API endpoint.

This is one of the most practical skills in API design and one of the things that separates a thoughtful API from a frustrating one. The rule is simple but important. Endpoints should be named after nouns, not verbs. This is because the HTTP method already describes what you are doing. You do not need to say it again in the URL.

An endpoint called slash get-user is poor design because GET is already in the HTTP method. The same endpoint done well is simply slash users slash the user ID. The method tells you what is happening, the URL tells you what you are acting on.

Use plural nouns for collections. When you are referring to a group of things, use the plural form in the URL. Slash users returns a list of users. Slash users slash 42 refers to the specific user with ID 42. Slash users slash 42 slash posts refers to all posts written by that user. This nesting makes relationships readable at a glance.

Keep paths lowercase and use hyphens if you need to separate words. Slash blog-posts is cleaner and more consistent than slash blogPosts or slash Blog_Posts. Consistency matters because developers who use your API will have to remember these paths. The less they have to think about capitalisation and formatting, the easier your API is to work with.

Image: Side-by-side comparison of good and poor API endpoint naming, showing resource-based clean URLs on one side and verb-based confusing URLs on the other Alt text: Side by side comparison of well-named REST API endpoints using nouns versus poorly named endpoints using verbs.

Part III: HTTP Request and Response Structure

An HTTP transaction consists of a Request sent by the client (e.g., your browser) and a Response sent back by the server. If client want to access any data then it send a request to server, server process the request and then provide response to the client. Here is the structural breakdown of both, which follow a very similar, predictable pattern.

1. HTTP Request Structure

An HTTP request tells the server what the client wants to do. It consists of four main parts:

[Method] [URL/Path] [Version]   <-- Request Line
[Header-Name]: [Value]          <-- Headers (Zero or more)
                                <-- Empty Line
[Body]                          <-- Message Body (Optional)

• Request Line: The action to perform (e.g., GET to fetch data, POST to submit data, DELETE to remove it).

  • Path: The target URL or directory on the server (e.g., /index.html or /api/v1/users).

  • HTTP Version: The protocol version being used (e.g., HTTP/1.1 or HTTP/2).

• Request Headers: Metadata about the request in Key: Value pairs. They provide context, such as the type of browser (User-Agent), the format of data expected (Accept), or authentication tokens (Authorization).

• Empty Line: A mandatory blank line (\r\n) that signals the end of the headers and the start of the body.

• Request Body (Payload): The actual data being sent to the server. This is optional and usually used with POST, PUT, or PATCH requests (e.g., a JSON payload or form data).

2. HTTP Response Structure

An HTTP response is what the server sends back after processing the request. Its structure mirrors the request:

[Version] [Status Code] [Phrase]  <-- Status Line
[Header-Name]: [Value]            <-- Headers (Zero or more)
                                  <-- Empty Line
[Body]                            <-- Message Body (Optional)

• Status Line: It is the combination of Version, Status Code, and Phrase.

  • HTTP Version: The protocol version (e.g., HTTP/1.1).

  • Status Code: A 3-digit no. indicating the outcome (e.g., 200 for success, 404 for not found, 500 for server error).

  • Reason Phrase: A short text description of the status code (e.g., OK, Not Found).

• Response Headers: Metadata about the server and the response. It tells the client how to handle the data, including the data type (Content-Type), data length (Content-Length), and caching rules (Cache-Control).

• Empty Line: A mandatory blank line separating headers from the response body.

• Response Body: The resource requested by the client. This could be HTML code for a webpage, an image file, or raw data (like JSON or XML).

What is HTTPS?

HTTPS (HyperText Transfer Protocol Secure) is simply:

HTTPS = HTTP + TLS

HTTP defines how data is exchanged.

TLS encrypts how the data travels.

Without TLS:                                         Without TLS:

    Client                                                  Client                                                        
       │                                                      │                                                      
       │  GET /login                                          │                                         
       │  username=ritesh                                     │    Encrypted Data                                         
       │  password=123456                                     │                                             
       │                                                      │                                         
    Internet                                               Internet
       │                                                      │                                         
       ▼                                                      ▼
    Server                                                  Server
Anyone on the network can read it.                  Even if someone intercepts the packets, they only see encrypted bytes.                            

What HTTPS Provides

HTTPS provides three major security properties.

• Confidentiality: Only the client and server can read the data.

• Integrity: Data cannot be modified while traveling.

• Authentication: How do you know you're talking to the real server?

What is TLS?

TLS stands for Transport Layer Security. It secures communication between two machines.

TLS is responsible for

• Encryption

• Authentication

• Integrity

• Secure key exchange

TLS replaced the older SSL (Secure Sockets Layer) protocol, which is now considered insecure.

HTTP vs HTTPS

Part IV: Status Codes Are Not Optional

HTTP status codes are one of the most commonly misused parts of API design, especially among beginners. It is tempting to return a 200 OK response for everything and include an error message inside the response body. Please do not do this.

Status codes exist for a reason. They tell the client at a protocol level whether the request succeeded, failed, or needs something additional. When you return 200 for an error, you break every tool and integration that relies on status codes to know what happened. Here are the ones you need to know as a beginner:

• 200 (OK): The request succeeded, and data is included in the response.

• 201 (Created): A new resource was created successfully.

• 204 (No Content): The request succeeded, but there is no content to return (common for DELETE operations).

• 400 (Bad Request): The client sent an invalid request, such as a missing required field or an invalid value.

• 401 (Unauthorized): The client is not authenticated.

• 403 (Forbidden): The client is authenticated but does not have permission to perform this action.

• 404 (Not Found): The requested resource does not exist.

• 422 (Unprocessable Entity): The request was understood, but the data failed validation.

• 500 (Internal Server Error): Something went wrong on the server side.

Image: A reference chart of commonly used HTTP status codes grouped by category, showing 2xx success codes, 4xx client error codes, and 5xx server error codes with brief descriptions Alt text: Reference chart of HTTP status codes showing 2xx success 4xx client error and 5xx server error codes with one line descriptions of each.

Error Messages That Actually Help:

A status code tells you something went wrong. An error message tells you what went wrong and ideally how to fix it.A poor error message looks like this. Something went wrong. A slightly better but still unhelpful error message looks like this. Error 400. A genuinely helpful error message looks like this. The email field is required and must be a valid email address.

Your error responses should be consistent in structure. Most well-designed APIs return an error object that includes an error code, a human-readable message, and optionally a field name if the error relates to a specific input. The error code is useful for clients that need to handle specific errors programmatically. The message is useful for developers debugging the integration. The field name helps frontend applications show the error next to the right input.

Do not expose internal server details in your error messages. Telling a client which line of code threw an exception, or which database query failed, is both unhelpful and a security risk. Keep error messages informative but clean.

Part V: URI vs URN vs URL

One of the most confusing topics in HTTP and API Design is the difference between URI, URL, and URN. Many developers use URI and URL interchangeably, and in day-to-day development, that's often acceptable. However, they are not the same thing. The easiest way to understand the difference is with a simple analogy: Think of a person.

• URI is their identity (it could be their name, their address, or both).

• URL is their physical home address (how you find them).

• URN is their legal name (unique to them, regardless of where they live).

1. URI (Uniform Resource Identifier)

A URI is the overarching umbrella term. It is a string of characters used to identify any resource (a webpage, a book, a person, a document) on the internet.

Both URLs and URNs are specific types of URIs. If something is a URL or a URN, it is automatically a URI.

Example: isbn:9780134685991

Analogy: "Identifier"

2. URL (Uniform Resource Locator)

A URL is a specific type of URI that not only identifies a resource but also tells you how to find it by specifying its location. If you type it into a browser address bar to load a page, it is a URL.

• Example: https://www.example.com/index.html

• Why it's a URL: It names the resource (index.html) and tells your browser exactly where to go and what protocol (https) to use to retrieve it.

3. URN (Uniform Resource Name)

A URN is a specific type of URI that identifies a resource by a unique name in a specific namespace, but it does not tell you where the resource is located or how to get it.

URNs are meant to be persistent; even if a website goes down or a file moves to a different server, its URN remains exactly the same.

• Example: urn:isbn:0451524934 (The URN for the book 1984)

• Why it's a URN: It uniquely identifies the specific book globally, but it doesn't tell you which website to visit or which store to go to in order to read it.

Part VI: Advanced REST API Design Concepts

1. Pagination

Pagination in API design is the process of splitting a large dataset into smaller, manageable chunks (pages) instead of returning the entire dataset in a single API response.

Think of it like browsing an e-commerce site: if you search for "shoes," the server doesn't load all 50,000 results at once. It gives you the first 20 or 50, and lets you click "Next" or "Page 2."

Why is Pagination Important?

• Performance & Speed: Fetching millions of rows from a database takes time and consumes massive amounts of CPU and memory. Smaller payloads mean faster response times.

• Reduced Bandwidth: It saves network bandwidth for both the server and the client (especially important for mobile users on limited data plans).

• Server Stability: It prevents Denial of Service (DoS) issues, where a single massive request accidentally crashes your server or database.

Common Pagination Strategies:

A. Offset-Based Pagination (Page/Limit)

This is the most common and traditional method. The client requests data using two parameters: a limit (how many items to return) and an offset (how many items to skip) or a page number.

• Example Request: GET /v1/products?page=3&limit=20

• Behind the Scenes (SQL): SELECT * FROM products LIMIT 20 OFFSET 40;

The Flaw: It doesn't handle real-time data well. If a new item is added to page 1 while a user is on page 2, the last item from page 1 shifts to page 2, causing the user to see a duplicate item. It also becomes very slow on massive datasets because the database still has to count through all the skipped rows.

B. Cursor Pagination

Instead of skipping a specific number of rows, the client passes a pointer (a cursor) that indicates where the last page left off. This cursor is usually a unique, sequential identifier like an ID or a timestamp.

• Example Request: GET /v1/products?limit=20&starting_after=prod_95x2

• Behind the Scenes (SQL): SELECT * FROM products WHERE id > 'prod_95x2' LIMIT 20;

The Flaw: It’s incredibly fast and immune to duplicate data issues (great for infinite scroll feeds like Twitter or Instagram). However, you cannot jump directly to a specific page (e.g., "Go to page 5"); you can only move sequentially forward or backward.

C. Keyset Pagination

It is an another special form of cursor pagination that uses sortable fields (often the primary key) and only supports sequential navigation. This pagination technique is great for append-only data like feeds or logs.

• Example Request: GET /v1/posts?afterId=100&limit=20

• Behind the Scenes (SQL): SELECT * FROM posts WHERE id > 100 LIMIT 20;

The Flaw: The client sends a request to server asking for the next 20 posts after the post with ID 100. The server queries the database and returns posts 101–120 (or the next 20 available posts) and the client uses the last returned ID (e.g., 120) for the next request.

2. Filtering

Filtering is an API feature that allows clients to retrieve only the records that match specific conditions, instead of fetching all records. Think of it like shopping on Amazon, there are 1 million products. If you search for "laptops", you don't want to receive every product. Instead, you apply filters such as:

• Brand = Apple

• Price < ₹1,00,000

• In Stock = true

The API returns only the products that satisfy those conditions.

Without Filtering:

Request:
  GET /products
Response:
  [
    { "id": 1, "category": "Laptop", "brand": "Apple" },
    { "id": 2, "category": "Phone", "brand": "Samsung" },
    { "id": 3, "category": "Laptop", "brand": "Dell" },
    ...
  ]

Without Filtering:

Request:
  GET /products?category=Laptop
Response:
  [
    { "id": 1, "category": "Laptop", "brand": "Apple" },
    { "id": 3, "category": "Laptop", "brand": "Dell" }
  ]

3. Sorting

Sorting is an API feature that allows clients to receive data in a specific order, such as ascending, descending, newest first, oldest first, highest price first, etc. Without sorting, the database may return records in an arbitrary order, which may not be useful to the client.

Without Sorting:

Request:
  GET /products
Response:
  [
    { "id": 3, "name": "Dell", "price": 80000 },
    { "id": 8, "name": "HP", "price": 55000 },
    { "id": 1, "name": "Apple", "price": 120000 }
  ]

With Sorting:

Request:
  GET /products?sort=price
Response:
  [
    { "id": 8, "name": "HP", "price": 55000 },
    { "id": 3, "name": "Dell", "price": 80000 },
    { "id": 1, "name": "Apple", "price": 120000 }
  ]

4. Searching

Searching is an API feature that allows clients to find resources that match a keyword or phrase, instead of retrieving all resources. Unlike filtering, which matches exact conditions (e.g., category=Laptop), searching looks for partial or relevant matches in one or more fields.

Without Searching:

Request:
  GET /videos
Response:
  [
    { "id": 1, "title": "Java Tutorial" },
    { "id": 2, "title": "System Design Basics" },
    { "id": 3, "title": "Node.js Course" },
    ...
  ]

With Searching:

Request:
  GET /videos?search=system design
Response:
  [
    {
      "id": 2,
      "title": "System Design Basics"
    },
    {
      "id": 5,
      "title": "Advanced System Design"
    }
  ]

5. Idempotency

Idempotency means that making the same API request multiple times has the same effect on the server as making it once. The response may or may not be identical, but the server's final state remains unchanged after the first successful request.

In simple words:

No matter how many times you repeat the same request, the result on the server stays the same.

Example of an Idempotent API

Suppose we have a user:
  {
    "id": 1,
    "name": "Ritesh"
  }
Request:
  DELETE /users/1

The user is deleted. Now send the same request again:
  DELETE /users/1

The user is already deleted.
The server state remains the same—user 1 is still absent. So DELETE is idempotent.

Part VII: Authentication and Authorization

Authentication and Authorization are two of the most important concepts in API design. They are often used together, but they solve different problems.

• Authentication answers: "Who are you?"

• Authorization answers: "What are you allowed to do?"

Authentication verifies identity. Authorization verifies permissions.

What is Authentication?

Authentication is the process of verifying the identity of a client (user, mobile app, or another service).

It answers:

"Are you really who you claim to be?"

Example:

Request:
  POST /login
Body:
  {
     "email": "ritesh@example.com",
     "password": "mypassword"
  }

The server checks:
  Does this email exist?
  Is the password correct?

If yes:
  {
     "accessToken": "eyJhbGciOiJIUzI1NiIs..."
  }

Common Authentication Methods:

1. Username & Password: Most basic authentication.

POST /login

2. JWT (JSON Web Token): After login, the server returns a JWT. Every future request includes:

Authorization: Bearer <JWT>

3. OAuth 2.0: Used when logging in with:

• Google

• GitHub

Instead of verifying the password itself, your application trusts another identity provider.

What is Authorization?

Authentication tells the server who you are. Authorization determines what you're allowed to do.

Example:

Suppose two users exist:
  Admin
  Customer
Both are authenticated.

Now consider:
  DELETE /users/15

Admin:
   Allowed ✅
Customer:
  Forbidden ❌

Same API. Same authentication but different authorization.

Authorization Models

There are several authorization models:

• RBAC (Role-Based Access Control)

• ABAC (Attribute-Based Access Control)

• ACL (Access Control List)

• PBAC (Policy-Based Access Control)

For most backend interviews, RBAC is the starting point.

Image: A flowchart showing the authentication and authorization process for an API request, from the client sending a token to the server validating it and checking permissions before returning a response Alt text: Flowchart showing API authentication and authorization flow from client request with JWT token to server validation and permission check before response.

Part VIII: Versioning Your API So It Does Not Break Things

APIs change over time. New features get added, old fields get renamed, some endpoints get deprecated entirely. The challenge is doing all of this without breaking the clients and integrations that are already using your API.

The solution is versioning. The most common approach is to include a version number in the URL, such as slash api slash v1 slash users. When you need to make a breaking change, you create a v2 and keep v1 running for existing clients. This gives dependent systems time to migrate at their own pace.

Some APIs use header-based versioning instead, where the version is passed as a request header rather than in the URL. This keeps URLs cleaner but makes the version less visible and harder to reason about for beginners. URL-based versioning is simpler to implement and understand, which is why it remains the most widely used approach.

The important thing to understand is that versioning is not something you add later as an afterthought. It is a decision you make at the start. Getting into the habit of building versioning into your API design from the beginning is one of the habits that separates a junior API designer from a more experienced one.

Part IX: Practicing All of This on ScaleDojo

Understanding these concepts in theory is useful. Practicing them by actually designing APIs and receiving specific feedback on your decisions is where the real skill development happens.

ScaleDojo has 50 API design levels that take you through progressively more complex scenarios. The early levels focus on fundamental REST design, naming conventions, and basic request-response structure. As you progress, the challenges introduce pagination, authentication, versioning, error handling, and more advanced patterns like rate limiting and idempotency.

The way it works is straightforward. Each level presents you with a system description and asks you to design the API for it. You think through the endpoints, the methods, the request and response formats, the status codes, and any other relevant considerations. You submit your design and the AI architect reviews it in detail, scoring your work and explaining what you got right and what could be improved.

This feedback loop is where the learning really happens. You might design an endpoint that technically works but violates a REST convention. The AI will tell you that, explain why the convention exists, and show you a better approach. You might forget to include pagination on a list endpoint. The AI will point out why that matters at scale. You might return the wrong status code for a validation error. The AI will explain the difference between a 400 and a 422 and when each one is appropriate.

Over 50 levels, this kind of specific, design-by-design feedback builds the intuition that makes good API design feel natural rather than effortful.

Image: A screenshot style representation of a ScaleDojo API design challenge showing a system description on one side and an API design canvas on the other where endpoints and response formats are defined Alt text: ScaleDojo API design level interface showing a system description alongside a canvas where a beginner is designing REST endpoints with methods and response structures.

Part X: What Production-Ready API Design Actually Means

The phrase production-ready gets used a lot. But what does it actually mean for an API?

It means the API handles errors gracefully and communicates them clearly. It means the endpoints are named consistently and behave predictably. It means the API uses proper status codes so that monitoring tools, integration partners, and frontend applications can all respond correctly. It means there is versioning in place so the API can evolve without breaking dependent systems. It means authentication and authorization are implemented correctly so the right people can do the right things and nothing more. It means list endpoints are paginated so they do not fall over when data volumes grow. It means the API is documented well enough that a developer who has never seen it before can start using it within an hour.

None of these things are individually complicated. But doing all of them consistently, thoughtfully, and from the start is what separates a production-ready API from one that becomes a maintenance headache six months later.

This is what you are building toward when you work through ScaleDojo's API design track. Not just the ability to name endpoints correctly, but the complete judgment to make all of these decisions together in a coherent and reliable way.

Where to Go From Here

If you are new to API design, the path is clear. Start by making sure you understand REST fundamentals, the five HTTP methods, resource-based endpoint naming, and consistent request-response structure. Then move into status codes and error handling. Then pagination and filtering. Then authentication and authorization. Then versioning.

Once you have the concepts, open ScaleDojo and find the API Design track in the roadmap. Work through the beginner-level challenges in order. Submit your designs, read the AI architect feedback carefully, iterate on your work, and move on when you feel confident.

The 50 API design levels on ScaleDojo give you a structured path from complete beginner to production-level thinking. Combined with the HLD and LLD tracks, you end up with a well-rounded understanding of how systems are designed at every level, from the big picture architecture all the way down to the individual API contract.

Start at the beginning, take it one level at a time, and let the AI feedback guide your improvement. That is the blueprint.