https://lexicon.kalyangopalam.com A knowledge base for learning — curated guides, community notes, and a private study library. Ask a question, get a clear answer, and keep what you learn. https://lexicon.kalyangopalam.com/notes/tcp-somethin-163b0128 https://lexicon.kalyangopalam.com/notes/tcp-somethin-163b0128 Mon, 27 Jul 2026 22:06:58 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood scorpionxdev · Jul 27,… https://lexicon.kalyangopalam.com/notes/tcp-somethin-a220b138 https://lexicon.kalyangopalam.com/notes/tcp-somethin-a220b138 Mon, 27 Jul 2026 22:01:12 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood scorpionxdev · Jul 27,… https://lexicon.kalyangopalam.com/notes/tcp-somethin-0f6d6e1a https://lexicon.kalyangopalam.com/notes/tcp-somethin-0f6d6e1a Mon, 27 Jul 2026 21:51:29 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood scorpionxdev · Jul 27,… https://lexicon.kalyangopalam.com/notes/only-bug-bounty-checklist-you-ll-ever-need-4847d21a https://lexicon.kalyangopalam.com/notes/only-bug-bounty-checklist-you-ll-ever-need-4847d21a Mon, 27 Jul 2026 21:28:51 GMT Global Manual Bug Bounty Checklist Purpose: A target-agnostic, manual-first checklist for authorized web, API, SaaS, identity, business-logic, integration, and client-side testing. Important: No checklist can guarantee a valid or paid bu… https://lexicon.kalyangopalam.com/notes/tcp-somethin-3e64bd92 https://lexicon.kalyangopalam.com/notes/tcp-somethin-3e64bd92 Mon, 27 Jul 2026 21:23:23 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood --- Compiled from a Le… https://lexicon.kalyangopalam.com/notes/tcp-somethin-fd3a827b https://lexicon.kalyangopalam.com/notes/tcp-somethin-fd3a827b Mon, 27 Jul 2026 21:23:15 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood --- Compiled from a Le… https://lexicon.kalyangopalam.com/notes/tcp-somethin-ec9d9171 https://lexicon.kalyangopalam.com/notes/tcp-somethin-ec9d9171 Mon, 27 Jul 2026 21:21:59 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood --- Compiled from a Le… https://lexicon.kalyangopalam.com/notes/tcp-somethin-d3b445e7 https://lexicon.kalyangopalam.com/notes/tcp-somethin-d3b445e7 Mon, 27 Jul 2026 21:21:49 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood --- Compiled from a Le… https://lexicon.kalyangopalam.com/notes/tcp-somethin-0d1a818c https://lexicon.kalyangopalam.com/notes/tcp-somethin-0d1a818c Mon, 27 Jul 2026 21:20:29 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood --- Compiled from a Le… https://lexicon.kalyangopalam.com/notes/tcp-somethin-6a95bfe1 https://lexicon.kalyangopalam.com/notes/tcp-somethin-6a95bfe1 Mon, 27 Jul 2026 21:19:54 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. scorpionxdev · Jul 27, 2026 yeah I understood --- Compiled from a Le… https://lexicon.kalyangopalam.com/notes/what-s-the-tcp-ip-1b3516c0 https://lexicon.kalyangopalam.com/notes/what-s-the-tcp-ip-1b3516c0 Mon, 27 Jul 2026 21:18:24 GMT Summary This is what i understood Question How exactly tcp ip works --- Discussion aria2 · Jul 27, 2026 No idea what is it. --- Key takeaway and Keep going --- Compiled from a Lexicon question thread. https://lexicon.kalyangopalam.com/notes/tcp-somethin-d235993a https://lexicon.kalyangopalam.com/notes/tcp-somethin-d235993a Mon, 27 Jul 2026 21:02:55 GMT Question no idea what is it --- Discussion scorpionxdev · Jul 27, 2026 I think it's all about having the tcp itself aria2 · Jul 27, 2026 I think that's good or no idea. --- Compiled from a Lexicon question thread. https://lexicon.kalyangopalam.com/notes/api-pagination-patterns-804dbf8c https://lexicon.kalyangopalam.com/notes/api-pagination-patterns-804dbf8c Mon, 27 Jul 2026 19:56:39 GMT When a collection is too big to return at once, you paginate. There are two main patterns and choosing wrong causes real pain at scale. Offset pagination The classic approach: skip N rows, take the next page. http GET /api/posts?limit=20… https://lexicon.kalyangopalam.com/notes/understanding-http-status-codes-92355cd6 https://lexicon.kalyangopalam.com/notes/understanding-http-status-codes-92355cd6 Mon, 27 Jul 2026 19:56:22 GMT Status codes are the server telling you what happened in one number. Learn the shape of each class and you can debug most APIs without reading a manual. The five classes Range Meaning --- --- 1xx Informational, rarely seen directly 2xx S… https://lexicon.kalyangopalam.com/notes/how-environment-variables-work-3f92a517 https://lexicon.kalyangopalam.com/notes/how-environment-variables-work-3f92a517 Mon, 27 Jul 2026 19:46:51 GMT Environment variables are named values that live in a process and get inherited by the processes it spawns. They are the standard way to pass configuration and secrets into an app without hardcoding them. Setting and reading them bash ex… https://lexicon.kalyangopalam.com/notes/only-bug-bounty-checklist-you-ll-ever-need-v2-2d0e300c https://lexicon.kalyangopalam.com/notes/only-bug-bounty-checklist-you-ll-ever-need-v2-2d0e300c Mon, 27 Jul 2026 08:51:58 GMT Global Manual Bug Bounty Checklist Purpose: A target-agnostic, manual-first checklist for authorized web, API, SaaS, identity, business-logic, integration, and client-side testing. Important: No checklist can guarantee a valid or paid bu… https://lexicon.kalyangopalam.com/notes/markdown-formatting-reference-82a75185 https://lexicon.kalyangopalam.com/notes/markdown-formatting-reference-82a75185 Sat, 11 Jul 2026 04:32:50 GMT A quick reference for GitHub-Flavored Markdown. The rendered output is on the left in your head; the source is below. Headings markdown H1 H2 H3 Emphasis markdown italic or italic bold strikethrough inline code Lists markdown - unordered… https://lexicon.kalyangopalam.com/notes/useful-linux-filesystem-commands-05f1b63c https://lexicon.kalyangopalam.com/notes/useful-linux-filesystem-commands-05f1b63c Mon, 06 Jul 2026 04:32:49 GMT A compact cheat sheet of filesystem commands I keep coming back to on the terminal. Moving around bash pwd where am I ls -lah long list, human sizes, include hidden files cd - jump back to the previous directory Finding things bash find … https://lexicon.kalyangopalam.com/notes/debugging-checklist-0a7a3c3e https://lexicon.kalyangopalam.com/notes/debugging-checklist-0a7a3c3e Sat, 04 Jul 2026 04:32:50 GMT When something breaks and I have no idea why, I run through this list before touching any code. It turns panic into a process. 1. Reproduce it reliably A bug you cannot trigger on demand is a bug you cannot fix with confidence. Find the … https://lexicon.kalyangopalam.com/notes/javascript-async-and-await-ea531c74 https://lexicon.kalyangopalam.com/notes/javascript-async-and-await-ea531c74 Sun, 28 Jun 2026 04:32:49 GMT async / await is syntax sugar over Promises that lets asynchronous code read top to bottom like normal code. Under the hood it is still Promises. The basics An async function always returns a Promise. await pauses inside that function un… https://lexicon.kalyangopalam.com/notes/git-commands-i-use-every-day-a85dd239 https://lexicon.kalyangopalam.com/notes/git-commands-i-use-every-day-a85dd239 Tue, 16 Jun 2026 04:32:49 GMT A short reference of the Git commands I actually reach for daily. Not exhaustive, just the ones that earn their keep. Checking state bash git status what changed, what is staged git status -sb compact one-line-per-file view git diff unst… https://lexicon.kalyangopalam.com/notes/how-caching-improves-application-performance-a3c3e309 https://lexicon.kalyangopalam.com/notes/how-caching-improves-application-performance-a3c3e309 Tue, 09 Jun 2026 04:32:50 GMT Caching is storing the result of expensive work so you can reuse it instead of redoing it. Done well it is the highest-leverage performance tool you have. Done badly it serves stale data and hides bugs. Why it works Most workloads are re… https://lexicon.kalyangopalam.com/notes/swiftui-state-management-34e861fb https://lexicon.kalyangopalam.com/notes/swiftui-state-management-34e861fb Sat, 06 Jun 2026 04:32:49 GMT SwiftUI rebuilds views from state. The trick is choosing the right property wrapper so ownership and updates flow the way you expect. The core property wrappers Wrapper Owns the data? Use for --- --- --- @State Yes simple value-type stat… https://lexicon.kalyangopalam.com/notes/kotlin-coroutines-overview-e443ce8b https://lexicon.kalyangopalam.com/notes/kotlin-coroutines-overview-e443ce8b Fri, 29 May 2026 04:32:49 GMT Coroutines are Kotlin's answer to asynchronous programming. They let you write concurrent code that reads sequentially, without blocking threads. Suspend functions A suspend function can pause and resume without blocking the underlying t… https://lexicon.kalyangopalam.com/notes/sql-joins-explained-d16acd31 https://lexicon.kalyangopalam.com/notes/sql-joins-explained-d16acd31 Sat, 23 May 2026 04:32:50 GMT A join combines rows from two tables based on a related column. The join type decides what happens to rows that have no match. Sample tables Say we have users and orders , where each order has a user id . INNER JOIN Only rows that match … https://lexicon.kalyangopalam.com/notes/database-indexing-basics-3fcae762 https://lexicon.kalyangopalam.com/notes/database-indexing-basics-3fcae762 Sun, 17 May 2026 04:32:49 GMT An index is a sorted lookup structure that lets the database find rows without scanning the whole table. It is the single biggest lever for query speed, and the most commonly overlooked. The book analogy Finding a topic by flipping every… https://lexicon.kalyangopalam.com/notes/react-component-design-principles-0559c061 https://lexicon.kalyangopalam.com/notes/react-component-design-principles-0559c061 Tue, 05 May 2026 04:32:49 GMT A handful of principles that keep React components easy to change. None of them are rules, but ignoring all of them tends to produce components that are painful to touch six months later. Keep components small and focused A component sho… https://lexicon.kalyangopalam.com/notes/clean-code-naming-practices-2daec637 https://lexicon.kalyangopalam.com/notes/clean-code-naming-practices-2daec637 Wed, 29 Apr 2026 04:32:50 GMT Naming is the cheapest documentation you will ever write and the first thing the next reader sees. A good name removes the need for a comment. Say what it is, not how it is stored Name things after intent. activeUsers beats arr , isExpir…