Linux systemd Services: A Practical Guide
Write, enable, and debug systemd services on Linux. Learn unit files, dependencies, restart policies, and journalctl logs through a small hands-on example.
·5 min read · #devops#linux#systemd
Blog
1745 posts · page 29 of 37
SSH Keys and Secure Server Access
Generate strong SSH keys, configure your ~/.ssh/config, lock down sshd, and use agent forwarding and jump hosts to access servers safely without passwords.
·5 min read · #devops#ssh#security
DSA Time Complexity Cheatsheet for Interviews
A printable cheatsheet of time and space complexities for arrays, hashmaps, trees, heaps, graphs, sorts, and common algorithms. Includes worst-case notes and quick rules of thumb.
·6 min read · #dsa#complexity#interviews
Find Minimum in Rotated Sorted Array — Binary Search
Solve Find Minimum in Rotated Sorted Array in logarithmic time with a modified binary search. Learn the pivot-finding invariant, edge cases, and how to extend the pattern to related problems.
·5 min read · #dsa#leetcode#binary-search
Fizz Buzz — A Clean, Extensible Solution
Solve Fizz Buzz with clean code and explore the string-concatenation pattern that avoids nested if-else. Python, Java, C++, and complexity analysis included.
·5 min read · #dsa#leetcode#beginners
Find Median from Data Stream — Two-Heaps Pattern
Solve Find Median from Data Stream with two heaps. Learn the balance invariant, why it gives O(log n) inserts and O(1) median, and the common pitfalls.
·5 min read · #dsa#leetcode#heap
Jump Game — Greedy Max-Reach Beats DP
Solve Jump Game with a single-pass greedy max-reach approach. Compare it against the dynamic programming solution and learn when greedy is provably optimal.
·4 min read · #dsa#leetcode#greedy
Maximum Product Subarray — Tracking Min and Max
Solve Maximum Product Subarray in linear time by tracking running min and max. Learn why negative numbers flip the role of min and max and see clean code.
·5 min read · #dsa#leetcode#dynamic-programming
Meeting Rooms II — Heap and Sweep Line
Solve Meeting Rooms II two ways: a min-heap of end times and a sweep-line over start and end events. Learn when each shines and how to pick in interviews.
·4 min read · #dsa#leetcode#heap
Merge Intervals — Sort and Sweep
Walk through Merge Intervals step by step. Brute force vs the optimal sort-and-sweep approach, edge cases, and clean code you can ship in an interview.
·5 min read · #dsa#leetcode#intervals
Palindrome Number — Without Converting to a String
Detect integer palindromes by reversing half the digits with integer math. Learn why string conversion is discouraged and how to handle negatives and trailing zeros.
·6 min read · #dsa#leetcode#math
Reverse String — Two-Pointer In-Place Solution
Solve the Reverse String problem in place using the two-pointer technique. Walkthrough, complexity analysis, edge cases, and clean Java, Python, and C++ implementations.
·4 min read · #dsa#leetcode#two-pointers
Rotate Array — The Triple-Reverse Trick
Rotate an array by k steps in O(1) extra space using the triple-reverse trick. Compare it with the extra-array approach and learn why this pattern keeps showing up.
·5 min read · #dsa#leetcode#arrays
JavaScript Array Methods: map, filter, reduce
Master the three most powerful array methods in JavaScript — map, filter, and reduce — with practical examples, chaining patterns, and performance tips.
·4 min read · #javascript#arrays#functional
JavaScript Async/Await Tutorial
Master async and await in JavaScript — write asynchronous code that reads like synchronous code, handle errors with try/catch, and parallelize work with Promise.all.
·4 min read · #javascript#async#await
JavaScript Closures and Scope
Understand JavaScript closures and lexical scope — see how inner functions remember outer variables, and learn the patterns that closures enable.
·4 min read · #javascript#closures#scope
JavaScript Promises Deep Dive
Go beyond the basics of JavaScript promises — explore the microtask queue, error propagation, cancellation patterns, and advanced combinators like any and allSettled.
·4 min read · #javascript#async#promises
The JavaScript this Keyword Explained
Demystify the JavaScript this keyword — understand how it changes by call site, why arrow functions differ, and how to bind context without surprises.
·4 min read · #javascript#this#binding
React Context API Guide
Learn how to use React's Context API to share state across your component tree without prop drilling — with patterns, performance tips, and common mistakes to avoid.
·4 min read · #javascript#react#context
React Custom Hooks Patterns
Learn powerful patterns for building React custom hooks — extracting logic, composing hooks, handling cleanup, and designing clean APIs your team will love.
·5 min read · #javascript#react#hooks
React Hooks Deep Dive: useState to useRef and When to Use Each
A practical deep dive into useState, useEffect, useMemo, useCallback, and useRef. Learn when to reach for each hook and the traps that ruin React code.
·6 min read · #react#javascript#hooks
React useEffect Common Mistakes
Avoid the most common useEffect mistakes — missing dependencies, infinite loops, stale closures, and effects that should not be effects in the first place.
·4 min read · #javascript#react#hooks
TypeScript Generics Introduction
An approachable introduction to TypeScript generics — learn type parameters, constraints, defaults, and how to build reusable type-safe functions and components.
·4 min read · #javascript#typescript#generics
Python async and await Basics
A gentle introduction to Python's async and await — coroutines, the event loop, awaiting tasks, asyncio.gather for concurrency, and when async actually helps.
·5 min read · #python#async#asyncio
Python Error Handling with try and except
A practical guide to error handling in Python — catching specific exceptions, the else and finally clauses, raising and re-raising, custom exception types, and habits that lead to robust code.
·5 min read · #python#exceptions#error-handling
Python f-Strings Formatting Guide
A complete guide to Python f-strings — basic interpolation, format specifiers for numbers and dates, alignment and padding, debug syntax, and when to choose other formatting methods.
·5 min read · #python#strings#formatting
Python Generators and the yield Keyword
Understand Python generators from the ground up — how yield turns a function into an iterator, lazy evaluation, generator expressions, and when generators beat lists.
·5 min read · #python#generators#iterators
Python List Comprehensions Deep Dive
Go beyond the basics of Python list comprehensions — filtering, nested loops, conditional expressions, dict and set comprehensions, and when a plain for loop is the better choice.
·5 min read · #python#comprehensions#lists
Introduction to Python Type Hints
A practical introduction to Python type hints — basic syntax, common collection types, Optional and Union, type-checking with mypy, and how hints improve code without changing runtime behaviour.
·5 min read · #python#type-hints#mypy
Python Virtual Environments Guide
Stop polluting your system Python — a practical guide to virtual environments with venv, activating and deactivating them, requirements.txt, and a quick look at modern alternatives.
·5 min read · #python#venv#packaging
Caching Strategies in System Design: A Practical Guide
Compare cache-aside, read-through, write-through, write-behind, and refresh-ahead. Learn when each strategy fits, what consistency you give up, and how to choose for interviews.
·6 min read · #system-design#caching#performance
Database Sharding Explained: Keys, Strategies, and Trade-offs
A practical introduction to sharding: range, hash, directory, and geo-based partitioning. Learn how to pick a shard key, handle hot shards, and plan resharding without downtime.
·6 min read · #system-design#databases#scalability
System Design Interview: A 7-Step Framework
A repeatable 7-step framework for system design interviews. Clarify, estimate, API, data model, high-level, deep dive, bottlenecks — with concrete examples for each step.
·5 min read · #system-design#interview-prep#career
gRPC Introduction: Protobuf, Streaming, and Why
A working introduction to gRPC: protobuf schemas, code generation, the four RPC styles, deadlines, errors, and when to pick it over REST.
·5 min read · #grpc#protobuf#intermediate
Idempotency Keys: Making APIs Safe to Retry
How idempotency keys work, where to use them, and how to implement them correctly so clients can safely retry POST requests without creating duplicates.
·5 min read · #api#reliability#intermediate
MongoDB Basics for Developers Coming From SQL
A practical introduction to MongoDB for developers familiar with relational databases: documents, collections, queries, indexes, and when to pick it over SQL.
·5 min read · #mongodb#databases#intermediate
JWT Authentication: How It Works and Where It Fails
A clear-eyed guide to JWTs: structure, signing, verification, refresh flows, and the real-world failure modes nobody warns you about.
·4 min read · #jwt#auth#intermediate
OAuth2 Explained: Flows, Tokens, and Real Examples
OAuth2 demystified for working developers: the four flows, access and refresh tokens, PKCE, scopes, and where security actually breaks in practice.
·4 min read · #oauth2#auth#intermediate
WebSockets in Node.js: Real-Time From Scratch
Build a real WebSocket server in Node.js: handshake, broadcasting, heartbeats, backpressure, and scaling beyond a single process.
·4 min read · #websockets#nodejs#intermediate
Redis Caching Patterns: TTL, Stampede, and Invalidation
Practical Redis caching patterns: cache-aside, write-through, TTL choices, stampede protection, and invalidation strategies that survive production.
·5 min read · #redis#caching#intermediate
AWS CDK: Infrastructure as TypeScript
Use the AWS Cloud Development Kit to define cloud infrastructure in TypeScript with constructs, stacks, and CloudFormation as the deploy engine.
·6 min read · #aws#cdk#intermediate
AWS CloudFront Basics: CDN for S3 and Beyond
Learn how Amazon CloudFront works: origins, distributions, cache behaviors, invalidations, signed URLs, and pairing CloudFront with S3 for static sites.
·6 min read · #aws#cloudfront#intermediate
AWS IAM Basics: Users, Roles, and Policies
Learn AWS IAM fundamentals: root vs IAM users, JSON policies, roles for services, least privilege, and common pitfalls that lead to security incidents.
·6 min read · #aws#iam#intermediate
AWS RDS Basics: Managed Relational Databases
A practical introduction to Amazon RDS: supported engines, instance types, backups and snapshots, multi-AZ deployments, parameter groups, and security.
·6 min read · #aws#rds#intermediate
AWS VPC Basics: Subnets, Route Tables, and Gateways
Understand AWS VPC fundamentals: public vs private subnets, internet and NAT gateways, route tables, and the difference between security groups and NACLs.
·7 min read · #aws#vpc#intermediate
C++ Classes, Constructors, and the Rule of Three
Design C++ classes with constructors, destructors, member initializer lists, and the Rule of Three and Five to manage resources safely.
·5 min read · #cpp#oop#intermediate
C++ Control Flow: if, for, while, switch
Master C++ control flow with if-else, for and range-for loops, while, do-while, switch, and the modern init-statement syntax for conditions.
·5 min read · #cpp#control-flow#beginner
Install C++ and Compile Your First Program
Set up a modern C++ toolchain on macOS, Linux, or Windows, then compile and run your first program with g++ or clang++ from the command line.
·4 min read · #cpp#setup#beginner