Understanding the Limitations of Pubsub SystemsPaper: Understanding the Limitations of Pubsub Systems Authors: Atul Adya, Phil Bogle, Colin Meek (Databricks) Venue: HotOS 2025 If you've ever built anything with Kafka, GCP Pub/Sub, RabbitMQ, or AWSAug 23 · 13 min readayush-pandit.hashnode.dev
Write-Through vs Write-Behind Caching: How High-Performance Systems Handle Writes1. Why Do We Need Caching for Writes? Most caching conversations start and end with reads: "the database is slow, put Redis in front of it." But in any system with real traffic, writes become the bottAug 19 · 22 min readayush-pandit.hashnode.dev
Replication Is Expensive. Here's How S3 Gets the Same Durability for Half the CostA deep dive from first principles to Reed-Solomon math to production architecture Why this matters If you've ever wondered how S3 promises 99.999999999% durability (eleven nines lose 1 object out of Jul 1 · 14 min readayush-pandit.hashnode.dev
How Google Lens Works: From Uploaded Image to Search Results1. Introduction: why reverse image search is a hard engineering problem Here's the trap juniors fall into with this topic: they assume the hard part is "the AI." It isn't. The model that turns an imagJun 28 · 16 min readayush-pandit.hashnode.dev
MongoDB Change Streams Internals From Database Writes to Real Time SystemsIf you ask ten backend engineers how MongoDB Change Streams work, most will answer something like: "You call watch() and MongoDB notifies you whenever a document changes." That answer is technicallyJun 28 · 9 min readayush-pandit.hashnode.dev
