Backend engineering guides

Java / May 10, 2026 / 5 min read

Time Complexity of Java Collections

A practical reference for Java collection time complexity, including ArrayList, LinkedList, HashMap, TreeMap, HashSet, and PriorityQueue.

• Java
• Collections
• Big-O
• Performance

Backend / May 3, 2026 / 7 min read

CSRF vs XSS: Key Differences for Backend Developers

Compare CSRF and XSS attacks for backend developers, including how they work, why cookies and tokens matter, and practical defenses.

• Security
• CSRF
• XSS
• Authentication

Backend / Apr 19, 2026 / 6 min read

OAuth 2.0 Explained for Backend Developers

A backend-focused OAuth 2.0 guide covering roles, authorization code flow, PKCE, scopes, tokens, client credentials, and common mistakes.

• Authentication
• OAuth
• Security
• Backend

Backend / Apr 12, 2026 / 6 min read

Access Token vs Refresh Token

Compare access tokens and refresh tokens in backend authentication, including lifetime, storage, rotation, revocation, and security tradeoffs.

• Authentication
• Security
• JWT
• OAuth

API Design / Apr 5, 2026 / 5 min read

Pagination Strategies for REST APIs

Compare offset, cursor, and keyset pagination for REST APIs, including tradeoffs, response shapes, sorting, and backend performance.

• REST
• API Design
• Pagination
• Performance

API Design / Mar 29, 2026 / 6 min read

Idempotency in APIs Explained

Learn what idempotency means in API design, why retries create duplicate actions, and how idempotency keys protect backend workflows.

• API Design
• REST
• Idempotency
• Distributed Systems

API Design / Mar 22, 2026 / 4 min read

REST API Status Codes Explained

Understand the HTTP status codes backend developers use most often in REST APIs, including 200, 201, 400, 401, 404, 409, and 500.

• REST
• HTTP
• API Design
• Status Codes

Java / Mar 15, 2026 / 4 min read

ConcurrentHashMap Explained

A practical explanation of ConcurrentHashMap in Java, including thread safety, atomic methods, iteration behavior, and common mistakes.

• Java
• ConcurrentHashMap
• Concurrency
• Collections

Java / Mar 8, 2026 / 3 min read

HashMap Load Factor Explained

Learn what HashMap load factor means in Java, how it affects resizing, memory usage, and lookup performance.

• Java
• HashMap
• Collections
• Performance

Java / Mar 1, 2026 / 3 min read

ArrayList vs LinkedList in Java

Compare ArrayList and LinkedList in Java by access patterns, insertion cost, memory overhead, and practical backend usage.

• Java
• Collections
• ArrayList
• LinkedList

Algorithms / Feb 4, 2026 / 2 min read

Big-O Notation Explained for Backend Developers

Learn Big-O notation with practical backend examples, including arrays, hash maps, sorting, nested loops, and database-like thinking.

• Big-O
• Algorithms
• Interview Prep

Backend / Jan 28, 2026 / 2 min read

JWT vs Session Authentication: Practical Backend Tradeoffs

Understand JWT and server-side session authentication, including storage, revocation, scaling, security risks, and common backend use cases.

• Authentication
• JWT
• Security

API Design / Jan 21, 2026 / 2 min read

REST vs RPC: How to Choose an API Style

Compare REST and RPC API styles through resources, actions, payload design, caching, versioning, and backend team workflows.

• REST
• RPC
• System Design

Java / Jan 14, 2026 / 1 min read

Java PriorityQueue Explained with Practical Examples

Learn how Java PriorityQueue works, when to use it, how ordering is defined, and common pitfalls around iteration and custom comparators.

• Java Collections
• PriorityQueue
• Algorithms

Java / Jan 8, 2026 / 2 min read

HashMap vs Hashtable in Java: Key Differences and When to Use Each

Compare HashMap and Hashtable in Java, including synchronization, null keys, performance, legacy status, and modern alternatives.

• Java Collections
• HashMap
• Concurrency

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