TL;DR
The article discusses the esp32-c3-adblock, an open-source DNS ad blocker created by Zed (M-Abozaid) that operates on the inexpensive ESP32-C3 microcontroller. This device can filter out ads and tracking domains for devices connected to a home or small office network without needing additional PSRAM (Pseudo Static Random Access Memory). Instead of using traditional RAM for storage, it cleverly utilizes flash memory to store sorted 40-bit FNV-1a hashes of domain strings, allowing it to handle over 500,000 domains effectively.