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What happens when a web server opens too many connections? A real bug story and a deep dive into TCP ephemeral port exhaustion.

SELECT COUNT(*) has to check every row (or index entry) in PostgreSQL, so counting can be slow on big tables. We learn why and when to use estimates instead.

This lecture explains how Linux uses SYN and accept queues per listening socket during the TCP handshake, and how multiple server processes share the same socket and queues.

Notes comparing session-based and JWT authentication, with a look at pros and cons.

A simple overview of the path a web request takes from the frontend to the backend server, including key stages and hidden costs.

Personal notes to my future self on what really happens when a request travels from the frontend through the kernel to the backend.

My personal notes on a blog I read about software design. The author explained why writing design documents can be more powerful than just code, diagrams, or slides.

The lecture explored how ChatGPT uses **Server-Sent Events** (SSE) and modern HTTP protocols (HTTP/2, HTTP/3) to stream responses and manage conversation state. *It covers key details like message IDs linking conversation context, short-lived tokens and pagination, and even a fun demo of two ChatGPT instances talking to each other.*