Full Width [alt+shift+f] Shortcuts [alt+shift+k]
Sign Up [alt+shift+s] Log In [alt+shift+l]
108

How Apple built iCloud to store billions of databases

from Engineer’s Codex [alt+shift+b] in programming

Apple uses Cassandra and FoundationDB for CloudKit, their cloud backend service. We take a look into how exactly each is used within their cloud and the problems they've solved.
14th Jan 2024

Stay updated

Get a weekly newsletter with the top 5 articles worth reading every week.

More from Engineer’s Codex

Tokenmaxxing, Promomaxxing, and Misaligned Incentives in Tech

When a measure becomes a target, it ceases to be a good measure.

7th May 2026 • 1 votes
Diving into Claude Code's Source Code Leak

Engineer’s Codex is a publication about real-world software engineering.

1st Apr 2026 • 2 votes
Everyone is a Staff Engineer Now

Engineer’s Codex is a newsletter about real-world engineering.

22nd Dec 2025 • 1 votes
How to Not Write "Garbage Code" (by Linus Torvalds)

Linus Torvalds, Creator of Git and Linux, on reducing cognitive load

12th Sep 2025 • 48 votes
How Cursor Indexes Codebases Fast

Merkle Trees in the real world

10th May 2025 • 89 votes

More in programming

A new home for all my apps: apps.chofter.com

Say hello to apps.chofter.com, the new home for everything I build. The speed at which I ship new things has massively increased with the advent of AI, and I’ve been encouraged by the fact that, as I approach my sixth decade, new ideas for useful & fun things to build still come at me apace. These no longer fit on my personal homepage, which is a combination of work experience, interests, things I made long ago that are no longer relevant (but still interesting), and of course, the many apps & tools I have out there in the wild right now. The site was 100% built using Claude Code, which did an amazing job of inspecting all the various websites, app stores and code bases and constructing a site in 30 minutes or so. I had to push it to make the site more SEO friendly, pre-rendered to HTML rather than over relying on client side rendering, but that was it. So there we go, enjoy the delightful and hopefully useful apps that I’ve already built and will continue to build in the future

7 hours ago • 1 votes
SumatraPDF new features: March 18, 2026

New in the SumatraPDF pre-release builds: DDE commands accept arguments Commands sent via DDE can take arguments, the same as in custom shortcuts (#5383). Loading message in tab While a document loads, its tab shows a “loading” message instead of the home page (#5385). Install 32-bit on 64-bit Windows The installer lets you install the 32-bit version on 64-bit Windows (#5379). Changes for this day · Full changelog

yesterday • 1 votes
An Update on Orion for Linux and Windows

Kagi is ending development of Orion for Linux and Windows and open-sourcing both so the community can carry them forward. Our small team will now focus fully on making Orion for macOS and iOS faster, more stable, and more capable.

2 days ago • 1 votes
Clip of me singing Despard in Ruddigore in 2013

A clip of me singing a funny song from Gilbert and Sullivan’s Ruddigore back in 2013

2 days ago • 1 votes
How and Why fork() Uses Copy-on-Write

In this video, we look at why fork() needs copy-on-write, how it works inside the kernel, and a memory usage problem that Instagram encountered with Python.

2 days ago • 1 votes
📚 BoredReading

You seem to be enjoying this.

Join free to unlock everything.

Create free account

Already have an account? Sign in