How PhonePe and Paytm Avoid Lost Money on System Crashes
How UPI apps like PhonePe/Paytm keep payments safe using idempotency, sagas, and state machines.
Polling, SSE, and WebSockets for Practicing Engineers
Deep dive into polling, SSE, and WebSockets with trade-offs, patterns, and code for real-time web apps.
OpenClaw: The Open‑Source AI Agent That Gets Work Done
Discover how OpenClaw, an open-source local AI agent, can automate real work in your life and business.
n8n Social Media Content Factory
Importable n8n workflow that turns one prompt into multi‑platform, AI‑generated, approved social posts.
Uber’s Core Services: Trips, Dispatch, Pricing, Payments Part 3
Deep dive into Uber’s main backend services and how they work together.
Uber’s Front Door: Designing the API Gateway Layer Part 2
Deep dive into Uber’s API gateway: front door, pipeline, scaling, and patterns.
Designing Uber: From Rainy Night to Requirements Part 1
Turn a rainy-night taxi story into clear, concrete Uber system requirements.
Two pointers is the first real “algorithmic pattern” Part 1
Learn the two pointers pattern with intuition, patterns, and code so you can crush array/string questions.