I published 2 posts:

During the holiday, I have migrated my information hub from Diigo to Readwise.


Reclipped is a tool to take timestamped notes on videos. It supports popular video platforms, such as YouTube and Vimeo.

┌ Hashed and Hierarchical Timing Wheels

Keeping a lot of timers is a common problem in many distributed system. The paper “Hashed and Hierarchical Timing Wheels: Data Structures for the Efficient Implementation of a Timer Facility – Varghese & Lauck 1987” has listed 7 data structures and recommended the last two: Hashing Wheel with Unordered Timer Lists and Hierarchical Timing Wheels.

The morning paper has a good summary and this video have listed several implementations.

How to Efficiently Choose the Right Database for Your Applications

In this post, the author shared two decision trees to choose SQL and NoSQL databases. He also shared some tips for choosing a database.

How to Craft the Perfect Daily Schedule (According to Science)

Know your energy pattern and match your tasks to your energy.

Mutation Driven Testing – When TDD Just Isn’t Good Enough

Write tests and ensure they all pass.

Repeat following procedure:

  • Mutate the code to introduce some bugs.
  • Check whether the bug is captured by test. If not, modify the existing test cases or add new ones.
  • Revert the bugs and ensure test is green again.

Fail at Scale - ACM Queue

Ben Maurer shared several software reliability techniques used in Facebook.

Writing a Time Series Database from Scratch

Fabian Reinartz introduced how he designed the V3 storage structure of Prometheus.

The essential of the design is splitting the data by time ranges.