A focused set of Node.js interview questions with concise, correct answers, covering the event loop, async patterns, modules, streams, and common gotchas. Useful whether you're preparing for an interview or screening candidates.
What is Node.js? A runtime that executes JavaScript outside the browser, built on Chrome's V8 engine. It uses a single-threaded, event-driven, non-blocking I/O model, ideal for I/O-heavy, concurrent workloads.
Is Node.js single-threaded?
A practical Bash reference for writing shell scripts: variables, conditionals, loops, functions, string and array handling, and the safety settings every script should start with. Copy-paste ready.
#!/usr/bin/env bash
set -euo pipefail # exit on error, unset var, and failed pipe
IFS=$'\n\t' # safer word splitting
The kubectl commands you reach for constantly: inspecting pods, logs, deployments, scaling, port-forwarding, contexts, and debugging a broken cluster. Copy-paste ready.
kubectl config get-contexts # list contexts
kubectl config current-context # which cluster am I on
kubectl config use-context my-cluster # switch context
A focused set of React interview questions with concise, correct answers, covering components, hooks, state management, rendering behavior, and performance. Useful for interview prep or screening candidates.
What is React? A JavaScript library for building user interfaces from composable, declarative components. It uses a virtual DOM to compute minimal real-DOM updates.
What is JSX?
A database-agnostic SQL reference (works on PostgreSQL, MySQL, SQL Server, SQLite): SELECTs, filtering, joins, grouping, subqueries, and the DDL/DML you use every day. Copy-paste ready.
SELECT * FROM users;
SELECT name, email FROM users;
SELECT DISTINCT country FROM users;
A regular-expression reference that works across most engines (PCRE, JavaScript, Python, Java, Go). Character classes, quantifiers, groups, lookarounds, plus copy-paste patterns for the things people actually match: email, URL, dates, IPs.
| Pattern | Matches |
|---|---|
. |
any character except newline |
\d |
digit [0-9] |
A practical comparison of GraphQL and REST: how they differ, where each shines, and how to choose. Includes concrete request examples and a decision guide.
REST exposes many endpoints, each returning a fixed shape. GraphQL exposes one endpoint where the client specifies exactly the shape it wants.
A focused set of Docker interview questions with concise, correct answers, covering images vs containers, the Dockerfile, volumes, networking, Compose, and best practices. Useful for interview prep or screening candidates.
What is Docker? A platform for packaging applications and their dependencies into portable containers that run consistently across environments.
Container vs virtual machine?
A focused set of Java interview questions with concise, correct answers, covering OOP, collections, memory and the JVM, concurrency, and common gotchas. Useful for interview prep or screening candidates.
What are the four pillars of OOP?
Encapsulation (hide state behind methods), Inheritance (reuse via extends), Polymorphism (one interface, many implementations), Abstraction (expose what, hide how).
== vs .equals()?
A focused set of Kubernetes interview questions with concise, correct answers, covering the control plane, pods, deployments, services, networking, storage, and troubleshooting. Useful for interview prep or screening candidates.
What is Kubernetes? An open-source platform for automating deployment, scaling, and management of containerized applications across a cluster of machines.
What are the main components of the control plane?