Exploring Tech, Finance & Productivity
Practical articles, free developer tools, and finance calculators. No jargon, no fluff.
Design Yelp / Nearby Friends - System Design
“Nearby Friends” looks like the Uber problem wearing a different hat - a map, some dots, find the ones near me. It is not. Uber asks “out of …
Read MoreSovereign Gold Bonds Maturing in 2026: What Holders Actually Earned
Most SGB articles you will read are a forecast: buy this, hold eight years, and here is a hypothetical CAGR. That era is over. The first big …
Read MoreTesting LLM Apps Is Nothing Like Testing Regular Code
Here is the assertion that breaks every engineer coming to LLM apps from normal software: assert output == expected is useless. You cannot …
Read MoreDesign Distributed Metrics & Log Aggregation - System Design
Everyone underestimates log aggregation because the demo is trivial: run an agent on a box, ship each line over the network, dump it into a …
Read MoreDesign Pastebin - System Design
Pastebin looks like a URL shortener with a bigger payload, and people design it that way: mint a key, stuff the text somewhere, return a …
Read MoreDesign Stock Exchange Order Matching - System Design
“Match buy and sell orders” sounds like a database join. Then you look at the constraints. A million orders a second arrive from thousands …
Read MoreLiquid Fund vs Savings Account vs Sweep-In FD for Your Buffer
Most people put their emergency fund in a savings account and never think about it again. That single default, held for years on a fund that …
Read MoreUsing AI Agents to Modernize Legacy Code - What Actually Works
If you have watched a demo where an AI agent “modernizes” a codebase in one shot, you have watched a toy. Point the same agent at a real …
Read MoreDesign an Airbnb / Hotel Booking System - System Design
“Design Airbnb” sounds like a listings app: a host posts a room, a guest searches a city, they book, money changes hands. The interviewer …
Read MoreDesign Instagram-like Photo Sharing - System Design
Instagram sounds like Twitter with pictures, and half of it is. The follow graph, the feed of people you follow, the celebrity who breaks …
Read MoreDesign Netflix Recommendation Engine - System Design
The recommendation engine is the product. Netflix does not have a search box you visit with intent; it has a home screen that must guess, …
Read MoreSuper Top-Up vs a Higher Base Health Cover: The Premium Math
The default advice is “buy the biggest base health cover you can afford.” It is also the most expensive way to reach a high sum insured. If …
Read MoreSystem Prompts Are Not Afterthoughts - They Are Your Architecture
Most teams treat the system prompt as a text field. Someone pastes a paragraph into a string literal, the demo works, and it ships. Then …
Read MoreDesign a Distributed Job Scheduler - System Design
Everyone thinks a job scheduler is a while loop with a sleep. “Check the clock, if a job is due run it, sleep a second, repeat - cron …
Read MoreDesign a Food Delivery System (Swiggy / Zomato) - System Design
“Design Swiggy” looks like a restaurant catalogue with a Buy button. Browse restaurants, tap dishes into a cart, pay, wait for food. The …
Read MoreDesign Google Maps / Nearby Search - System Design
“Design Google Maps” sounds like it is about drawing a map. It is not. The map tiles are the easy, cacheable part. The interviewer is really …
Read MoreStreaming LLM Responses Without Making Your UX Feel Broken
Streaming looks solved. You flip stream=True, loop over deltas, append text to a div, and the demo feels magical. Then it ships, and the bug …
Read MoreThe Rupee Cost of Starting Your SIP Five Years Late
“I will start next year, once my salary jumps and the car loan is done.” It sounds responsible. Delay a five-year plan by five years and you …
Read MoreBuild Your Own MCP Server - The Tutorial Nobody Wrote
Search “MCP server” and you get a thousand guides that all stop at the same place: paste this JSON into your Claude config, restart, done. …
Read MoreDesign a Distributed Unique ID Generator - System Design
Almost every large system needs one boring-sounding thing: a way to mint unique identifiers. Tweet IDs, order IDs, message IDs, row keys. It …
Read MoreDeveloper Tools
JSON Formatter
Format, validate & minify JSON instantly in your browser.
Open ToolJWT Decoder
Inspect JWT header, payload, and expiry without sharing tokens.
Open ToolProtobuf Encoder
Encode JSON to Protobuf binary or decode binary back to JSON.
Open ToolRegex Tester
Test regex patterns with real-time matching and group highlights.
Open ToolBase64 Encoder
Encode and decode Base64 strings with a single click.
Open ToolHash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes instantly.
Open ToolUUID Generator
Generate random v4 UUIDs. Copy with one click.
Open ToolUnix Timestamp
Convert between Unix timestamps and human-readable dates.
Open ToolFinance Calculators
SIP Calculator
Calculate monthly SIP growth with the power of compound interest.
EMI Calculator
Find your EMI for home loans, car loans, or personal loans.
1 Crore SIP
Figure out how much SIP you need to build 1 crore.
Emergency Fund
Calculate exactly how much emergency fund you should have.
HRA Calculator
Compute your tax exemption under Section 10(13A).
Investment Growth
Project your portfolio's future value with annual step-ups.
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