System design

Modern C# Collections in Practice: List, Dictionary, Immutable Collections, and Custom Structs

1 Why Collection Choice Is an Architectural Decision Modern .NET systems don't fail because a for loop was slow. They fail because a hot path allocates too much, because a dictionary lookup cr

The Power Grid Explained: How Electricity Travels from Power Plant to Your Outlet in Milliseconds

1 The Invisible Speed of Light: Introduction to the Grid Electricity feels instant. You flip a switch, and the light turns on with no noticeable delay. What makes that possible isn’t stored energy

SurveyMonkey-Scale Platform: Branching Logic, Real-Time Analytics, and 100 Million Responses Per Month

Sudhir Mangla
Practical Design , Software Architecture
16 Jan, 2026

1 SurveyMonkey-Scale Platform: Branching Logic, Real-Time Analytics, and 100 Million Responses Per Month This section establishes the architectural baseline for a survey platform operating at Surv

The Hidden Complexity of Digital Maps: How Google and Apple Know About That New Coffee Shop

1 Introduction: The Illusion of Simplicity Most people open a maps app, type “coffee,” and expect useful results almost instantly. They don’t think about what happens next, and honestly, they shou

Movie Review Aggregation: Web Scraping, Score Normalization, and Real-Time Updates like Rotten Tomatoes

1 Architectural Blueprint: Moving Beyond Simple Scraping Most movie review aggregators begin as small utilities: fetch a page, scrape a number, store it somewhere. That works for a prototype, but

How Credit Card Transactions Actually Work: The 2-Second Journey Through 6 Different Systems

1 The Physical Layer: The Terminal Kernel & NFC Handshake (0ms–200ms) Every card transaction starts in the physical world, long before any network request is sent or any fraud model runs. This fir

Enterprise Calendar Systems: Conflict Resolution, Time Zone Handling, and Exchange/Google Calendar Sync

1 Architectural Foundations of a Global Scheduling System At first glance, a scheduling system looks straightforward: create events, update them, show availability, and sync with other calendars.

Hotel Booking Systems That Scale: Inventory Management, Double-Booking Prevention, and Dynamic Pricing with .NET

1 Architectural Blueprint: Designing for 50k Daily Bookings A hotel booking system at scale is not “just a database with some CRUD screens.” Once you support tens of thousands of bookings a day, t

Building Zoom at Scale: WebRTC, Selective Forwarding Units, and 50 Million Daily Meeting Participants in .NET

1 Architectural Foundations: Mesh vs. MCU vs. SFU Building a real-time video platform that supports 1,000-person meetings or tens of millions of daily participants forces you to confront architect

Real-Time Recommendation Engines in .NET: Combining Collaborative Filtering, Deep Learning, and Vector Databases

Sudhir Mangla
Practical Design , AI & Machine Learning
26 Nov, 2025

1 The Modern Recommendation Landscape: Beyond Simple Filtering A recommendation engine must predict what a user is likely to want at the moment they need it. Early systems relied heavily on collab

BookMyShow's Seat Selection Architecture: Distributed Locks, Payment Orchestration, and Zero Double-Bookings at Scale

1 Architectural Blueprint: Designing for 1 Million Daily Bookings When you design a seat-selection and booking system that behaves like BookMyShow or Ticketmaster, the core challenge is simple to

Building Uber's Dynamic Pricing Engine in .NET: Supply-Demand Algorithms, Geospatial Indexing, and Real-Time Market Simulation

1 Building Uber’s Dynamic Pricing Engine in .NET: Supply-Demand Algorithms, Geospatial Indexing, and Real-Time Market Simulation Uber’s pricing engine is one of the most fascinating real-time syst

Modern C# Collections in Practice: List, Dictionary, Immutable Collections, and Custom Structs

The Power Grid Explained: How Electricity Travels from Power Plant to Your Outlet in Milliseconds

SurveyMonkey-Scale Platform: Branching Logic, Real-Time Analytics, and 100 Million Responses Per Month

The Hidden Complexity of Digital Maps: How Google and Apple Know About That New Coffee Shop

Movie Review Aggregation: Web Scraping, Score Normalization, and Real-Time Updates like Rotten Tomatoes

How Credit Card Transactions Actually Work: The 2-Second Journey Through 6 Different Systems

Enterprise Calendar Systems: Conflict Resolution, Time Zone Handling, and Exchange/Google Calendar Sync

Hotel Booking Systems That Scale: Inventory Management, Double-Booking Prevention, and Dynamic Pricing with .NET

Building Zoom at Scale: WebRTC, Selective Forwarding Units, and 50 Million Daily Meeting Participants in .NET

Real-Time Recommendation Engines in .NET: Combining Collaborative Filtering, Deep Learning, and Vector Databases

BookMyShow's Seat Selection Architecture: Distributed Locks, Payment Orchestration, and Zero Double-Bookings at Scale

Building Uber's Dynamic Pricing Engine in .NET: Supply-Demand Algorithms, Geospatial Indexing, and Real-Time Market Simulation

Twitter's Trending Topics in .NET: Real-Time Stream Processing, Locality-Sensitive Hashing, and Geospatial Clustering

Smart Parking Systems in .NET: IoT Integration, Computer Vision, and Real-Time Availability with 99.9% Accuracy

360-Degree Performance Reviews: Configurable Workflows, Anonymous Feedback, and Goal Tracking with .NET

Real-Time Multiplayer Card Games in .NET: Deterministic Lockstep, Client Prediction, and Anti-Cheat Architecture

Engineering URL Shorteners at Scale: Beyond Base62 - Distributed ID Generation, Cache Warming, and Analytics Pipelines

Grammarly in .NET: Real-Time Grammar Checking, Context-Aware Suggestions, and Processing 1 Billion Words Daily

Distributed ID Generation at Scale: From Snowflake to ULID - Building Instagram's ID System in .NET

Building Dropbox in .NET: From Chunked Uploads to Merkle Trees - A Production Architecture for Petabyte-Scale File Sync