Sealed Classes and when in Kotlin
Use sealed classes, sealed interfaces, and when expressions to model state safely. The compiler will report an error immediately when you forget to handle a case.
Traits in Rust: Defining Shared Behavior
Learn how to define and implement traits in Rust, use trait bounds, impl Trait, dyn Trait, and avoid common errors like the orphan rule.
unknown, any, and never in TypeScript: which one to use
Differentiate any, unknown, and never in TypeScript with concrete examples: when to use, when to avoid, and exhaustive checking patterns.
Virtual environment, pip and pyproject.toml in Python
How to create virtual environments, manage packages with pip, and declare Python projects with pyproject.toml, with working examples and common errors.
Writing Controller Tests with @WebMvcTest and MockMvc
How to use @WebMvcTest, MockMvc, and @MockitoBean to quickly test REST controllers, loading only the web layer, checking JSON, validation, and exception handling.
Borrowing and Lifetime in Rust through Examples
Explaining borrowing, borrow checker, and lifetime annotation in Rust with easy-to-understand Order and Customer examples, plus common errors.
Centralized Exception Handling with @ControllerAdvice
Guide to using @ControllerAdvice and @ExceptionHandler for centralized error handling, returning standardized responses instead of scattered try-catch blocks across controllers.
Context in Go: timeout, cancel, and value passing
Learn how to use context.Context in Go to control timeout, deadline, cancel goroutines, and pass request-scoped values safely.
Data Class and Copy in Kotlin
Understand what Kotlin generates for a data class, how to use the copy() function to safely create copies, and common mistakes when comparing or inheriting.
Decorators in Python: From Basics to Parameters
Learn Python decorators from @ syntax, closure, functools.wraps to parameter-accepting decorators and class-based decorators.
Extension Functions in Kotlin: Adding Methods to Existing Classes
Learn how to use extension functions in Kotlin to extend existing classes without inheritance, with practical examples and tips.
Generators and yield in Python: Process Large Data Without Wasting RAM
Learn about generators, yield, and how they help process huge files or stream data without loading everything into memory.
Goroutine Leak: Silent Memory Eater in Golang
Goroutine leaks don't crash immediately but silently consume RAM over time. This article reveals common causes, detection methods, and thorough fixes.
Optional in Java: Using it Correctly and Common Anti-Patterns
A guide to using Optional in Java correctly, with common anti-patterns and how to avoid them for clearer, safer code.
Result and Option: Rust-Style Error Handling
Learn about Option<T> and Result<T, E> in Rust: how to represent missing values, potential failures, and propagate errors using the ? operator instead of exceptions.
Spring Data JPA: Repository, Query Methods, and @Query
Learn how Spring Data JPA auto-generates repositories, naming conventions for query methods, and when to use @Query for precise control over statements.
Stream API: map, filter, reduce and collect through examples
Learn the four "pillars" of Stream API in Java through practical examples with Order, Customer – from filtering data to aggregating results.
Union, Intersection and Narrowing in TypeScript
Learn how to combine types with union and intersection, and how TypeScript narrows types to write safer code with fewer runtime errors.
Utility Types in TypeScript: Partial, Pick, Omit, Record
Learn how to use Partial, Pick, Omit, and Record to reuse types and reduce duplicate interfaces in TypeScript.
asyncio or threading? Decide with 3 key questions
Distinguish asyncio and threading in Python with 3 practical questions, helping you choose the right concurrency model for each type of problem.