--- title: "Sarmeet Singh (@blueprintsofscale) | Hashnode" description: "Sarmeet Singh (@blueprintsofscale) writes on Hashnode. Read their latest articles and follow their work." url: "https://hashnode.com/@blueprintsofscale" --- @blueprintsofscale # Sarmeet Singh @blueprintsofscale · New York City, USA · Joined September 2026 ### [One Leader, Many Witnesses: Consensus and Leader Election, Explained Like You're New](https://blueprintsofscale.hashnode.dev/one-leader-many-witnesses-consensus-and-leader-election-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) Your database cluster has three machines. The leader dies mid-write. In the next two seconds, two different replicas each conclude that they are in charge, accept writes the other never sees, and your 37 min read · [blueprintsofscale.hashnode.dev](https://blueprintsofscale.hashnode.dev/one-leader-many-witnesses-consensus-and-leader-election-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) [Nov 2](https://hashnode.com/posts/one-leader-many-witnesses-consensus-and-leader-election-explained-like-you-re-new/6ae847886694427f0f133aff) ### [The Log That Remembers: Event Streaming and Pub-Sub, Explained Like You're New](https://blueprintsofscale.hashnode.dev/the-log-that-remembers-event-streaming-and-pub-sub-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) An order is placed. In the next second, five different systems need to know about it. Billing needs to charge the card. Inventory needs to reserve the item. Shipping needs a label. The recommendations 50 min read · [blueprintsofscale.hashnode.dev](https://blueprintsofscale.hashnode.dev/the-log-that-remembers-event-streaming-and-pub-sub-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) [Nov 2](https://hashnode.com/posts/the-log-that-remembers-event-streaming-and-pub-sub-explained-like-you-re-new/6ae8471ccabdebf07aad575a) ### [Same Data, Different Answers: Consistency, Explained Like You're New](https://blueprintsofscale.hashnode.dev/same-data-different-answers-consistency-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) You change your display name. The page says saved. You refresh, and the old name is back. You refresh again, and the new name returns. Nothing crashed. No one else edited your profile. The database si 39 min read · [blueprintsofscale.hashnode.dev](https://blueprintsofscale.hashnode.dev/same-data-different-answers-consistency-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) [Nov 2](https://hashnode.com/posts/same-data-different-answers-consistency-explained-like-you-re-new/6ae846af6694427f0f10e457) ### [From One Timeline to 500 Million Tweets a Day: Designing Twitter/X in 11 Steps](https://blueprintsofscale.hashnode.dev/from-one-timeline-to-500-million-tweets-a-day-designing-twitterx-in-11-steps?utm_source=hashnode&utm_medium=feed) Blueprints of Scale — Design Walkthrough #2 75 min read · [blueprintsofscale.hashnode.dev](https://blueprintsofscale.hashnode.dev/from-one-timeline-to-500-million-tweets-a-day-designing-twitterx-in-11-steps?utm_source=hashnode&utm_medium=feed) [Oct 12](https://hashnode.com/posts/from-one-timeline-to-500-million-tweets-a-day-designing-twitterx-in-11-steps/6acc6f9d3cfb2146aca8d3f4) ### [The Database Menu: SQL vs NoSQL, Explained Like You're New](https://blueprintsofscale.hashnode.dev/the-database-menu-sql-vs-nosql-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) Blueprints of Scale — Core Concepts #16 46 min read · [blueprintsofscale.hashnode.dev](https://blueprintsofscale.hashnode.dev/the-database-menu-sql-vs-nosql-explained-like-you-re-new?utm_source=hashnode&utm_medium=feed) [Oct 12](https://hashnode.com/posts/the-database-menu-sql-vs-nosql-explained-like-you-re-new/6acc6f80ade6a88144e336b4)