21 lessons from 14 years at Google

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I can't believe it's almost the end of 2025. This year, I worked on the foundations and the less visible parts of the newsletter. It is back on a homebrewed self-hosted platform with improved deliverability and performance. Emails are more accessible and cleaner. And I'm following almost 1000 different authors and websites every day to find the most interesting articles.

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21 lessons from 14 years at Google
12 minutes by Addy Osmani

Addy shares key lessons he's learned during his 14 years at Google. He argues the most successful engineers focus on solving user problems, work well with people, and prioritize clarity over cleverness. They ship imperfect solutions quickly to learn from real feedback rather than debating perfect designs. Success comes from building relationships, removing unnecessary work, and understanding that good engineering is ultimately about people.

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Why does Cloudflare use lava lamps to help with encryption?
8 minutes by Cloudflare

Cloudflare uses about 100 lava lamps in their lobby to create strong encryption keys. A camera takes photos of the lamps and converts them into random numbers that computers need for secure encryption. Since computers are designed to be predictable, they cannot generate truly random data on their own. The unpredictable movements of lava lamp contents provide the randomness needed to protect encrypted data from attackers.

Build a working game of Tetris in Conway's game of life
10 minutes by Totally Human

This discussion explores building a Tetris game within Conway's Game of Life using cellular automaton rules. The solution must accept input by manually changing cell states to represent game controls like piece movement and rotation. Performance is judged on five criteria: smallest bounding box area, fewest manual cell changes needed for input, fastest execution speed, lowest initial live cell count, and earliest submission time.

A modern guide to SQL JOINs
32 minutes by Alexey Makhotkin

Alexey's technical guide takes a fresh approach to teaching SQL JOINs by starting with LEFT JOIN instead of INNER JOIN. It emphasizes using only ID equality comparisons in ON conditions and avoiding the confusing 1:N case of LEFT JOIN. He presents JOINs through practical examples with an employee payment database.

How Pinterest built a real‑time radar for violative content using AI
10 minutes by Faisal Farooq et al.

Pinterest created an AI system to measure how often users see harmful content on their platform. The system samples content based on user views and uses AI to label it, providing daily reports on policy violations. This replaced expensive human reviews that took six months, giving Pinterest real-time insights to quickly detect problems and improve safety measures.

And the most popular article from the last issue was:

• How good engineers write bad code at big companies