DEV Community: Anubhav Ranjan

Master API Security from Scratch – Course Introduction by Code Spark

Anubhav Ranjan — Sun, 26 Oct 2025 15:01:11 +0000

Full Video Link : (https://youtu.be/qgYDdbCb4FM)
What if I told you that 83% of data breaches happen because of weak API authentication? Hi, I'm Anubhav Ranjan, a Software Developer from Bangalore, and today we're starting a comprehensive course that will transform how you think about API security.

This API Authentication & Security course is designed specifically for developers who want to master real-world authentication systems. Whether you're a junior developer struggling with OAuth implementations or a senior engineer architecting enterprise security solutions, this course covers everything from fundamental concepts to advanced security patterns.

Over the next several sessions, we'll journey through:

API fundamentals and security landscape
Authentication vs Authorization (and why the difference matters)
JWT tokens and session management
OAuth 2.0 implementation patterns
Zero Trust API architecture
Real-world security vulnerabilities and how to prevent them

By the end of this series, you'll confidently implement production-ready authentication systems and understand security patterns used by companies like Google, GitHub, and Stripe.

If you're ready to level up your API security skills, hit that subscribe button and ring the notification bell – we're releasing new episodes every week. Drop a comment below telling me what specific authentication challenge you're facing right now.

Why MD5 Password Hashing is a Terrible Idea

Anubhav Ranjan — Sat, 27 Sep 2025 17:44:35 +0000

This Java feature feels like cheating

Anubhav Ranjan — Thu, 14 Aug 2025 04:25:49 +0000

Ready to delete 98% of the code in your Java data classes? The endless boilerplate of constructors, getters, equals(), hashCode(), and toString() is a classic Java pain point.

Watch the full tutorial here

This "Clean" Java Code Hides a Bug! 🐛

Anubhav Ranjan — Tue, 12 Aug 2025 18:35:24 +0000

Ever written super clean Java code, only to have it crash with a mysterious UnsupportedOperationException? You've likely stumbled upon one of the most important concepts in modern programming: Mutability vs. Immutability.

🎥 Watch here:
👉 This "Clean" Java Code Hides a Bug! 🐛

🐳 Docker Explained with a Food Truck 🍔

Anubhav Ranjan — Tue, 12 Aug 2025 18:34:08 +0000

Ever struggled to explain Docker to someone new?
Think of it like a food truck.

🎥 Watch here:
👉 Docker Explained with a Food Truck

Your Java Switch Statements are Outdated! ❌

Anubhav Ranjan — Tue, 12 Aug 2025 18:30:54 +0000

Is your Java code full of long, clunky switch statements? The old way is verbose and can lead to silent, hard-to-find bugs if you forget a break.

🎥 Watch the full explanation here:
👉 Make your switch more readable

Your Java Strings are a MESS! 🤢

Anubhav Ranjan — Tue, 12 Aug 2025 18:29:34 +0000

Are you tired of ugly, unreadable multi-line strings in your Java code? Stop the mess of endless plus signs (+), newline characters (\n), and escaped quotes (\")!

🎥 Watch the full explanation here:
👉 Beautify your strings

Stop Writing Java Like This! 🤯

Anubhav Ranjan — Tue, 12 Aug 2025 18:27:33 +0000

If you write Java in 2025, you need to know this trick.
🎥 Watch the full explanation here:
👉 Stop Writing Verbose Java Code!

LeetCode Flood Fill Solved — DFS Clicked at 1 AM 😴

Anubhav Ranjan — Tue, 29 Jul 2025 04:03:02 +0000

🧩 The Problem: Flood Fill (LeetCode #733)
You’re given a 2D image represented as a grid, where each cell has a pixel value.
Starting from a pixel (sr, sc), you need to replace all connected pixels of the same color with a new color — just like the paint bucket tool in MS Paint!

🔍 Approach: Depth-First Search (DFS)
Store the original color of the starting pixel.

Use DFS to visit all 4-directionally connected cells of the same color.

Replace their color after DFS completes.

Track visited cells to avoid infinite recursion.

public static int[][] floodFill(int[][] image, int sr, int sc, int color) {
    int n = image.length, m = image[0].length;
    int initialColor = image[sr][sc];
    boolean[][] vis = new boolean[n][m];
    dfs(image, sr, sc, initialColor, n, m, vis);
    for (int i = 0; i < n; i++)
        for (int j = 0; j < m; j++)
            if (vis[i][j]) image[i][j] = color;
    return image;
}

private static void dfs(int[][] image, int r, int c, int color, int n, int m, boolean[][] vis) {
    if (r < 0 || c < 0 || r >= n || c >= m || vis[r][c] || image[r][c] != color) return;
    vis[r][c] = true;
    dfs(image, r+1, c, color, n, m, vis);
    dfs(image, r-1, c, color, n, m, vis);
    dfs(image, r, c+1, color, n, m, vis);
    dfs(image, r, c-1, color, n, m, vis);
}

💡 Takeaways
Perfect problem to learn 2D grid traversal + DFS

Similar to: Number of Islands, Surrounded Regions

Great for coding interviews and CodeSignal tests (Visa, Uber, etc.)

💬 What I Learned:
Matrix problems need boundary checks + visited tracking

Visualizing as a graph helped a lot!

Solving this gave me the confidence to tackle Number of Islands next

📢 Let’s Connect
I’m sharing my DSA progress + ChatGPT-based workflows every day on Dev.to.
Drop your thoughts, optimizations, or alternate solutions below 👇