SSSarmeet Singhinblueprintsofscale.hashnode.dev·6d ago · 75 min readFrom One Timeline to 500 Million Tweets a Day: Designing Twitter/X in 11 Steps"Design Twitter" might be the most-asked system design question there is, and it earns the reputation. The product fits in one sentence: people post short messages, follow each other, and read a timel00
SSSarmeet Singhinblueprintsofscale.hashnode.dev·6d ago · 46 min readThe Database Menu: SQL vs NoSQL, Explained Like You're NewEvery backend project reaches the same question sooner or later: which database should we use? The useful answer is that it depends on three things: what you're storing, how you'll read it, and how mu00
SSSarmeet Singhinblueprintsofscale.hashnode.dev·6d ago · 46 min readAll or Nothing: Distributed Transactions, Explained Like You're NewIn a lot of software, checkout is the most dangerous button. One click has to set off two things that must both happen or both not happen: the payment service charges the card, and the inventory servi00
SSSarmeet Singhinblueprintsofscale.hashnode.dev·Sep 29 · 47 min readWhat Broke at 3 AM: Observability, p99, and Useful Alerts, Explained Like You're NewThe page comes at 3:07 AM: "the site is slow." You open the dashboards. CPU: fine. Memory: fine. Error rate: flat. Every graph is green, and the site is still slow. Three engineers stare at the same s00
SSSarmeet Singhinblueprintsofscale.hashnode.dev·Sep 29 · 58 min readAssume They're Already Knocking: Security and Abuse at Scale, Explained Like You're NewIn the URL shortener post, the interviewer asked the meanest question near the end. The design was done, sharded and cached and replicated across regions, and then: "Your Base62 keys are sequential. I11J
