Engineer's Codex
read.engineerscodex.com · Group blog · on HN since 2023
Engineer's Codex is a newsletter that summarizes engineering practices and system designs at large tech companies.
What HN saysCommenters recommend it and link its posts on how Apple built iCloud on FoundationDB, Google's code review, and a $60M one-line bug.
22HN people shared it
10linked it in comments
14stories submitted
1.4Kstory points
4 months agolast shared
2023people per year2026
Most-shared posts
- 1Apple built iCloud to store billions of databases4 people · 497 points · first shared 2024 · 190 comments on HN
- 2How Google takes the pain out of code reviews, with 97% dev satisfaction4 people · 9 points · first shared 2024 · 1 comments on HN
- 3Meta's serverless platform processing trillions of function calls a day (2023)3 people · 50 points · first shared 2023 · 35 comments on HN
- 4One line of code caused a $60M loss3 people · 7 points · first shared 2024 · discussion on HN
- 5Meta's new LLM-based test generator2 people · 360 points · first shared 2024 · 190 comments on HN
- 6How Pinterest scaled2 people · 189 points · first shared 2023 · 147 comments on HN
- 7Good programmers worry about data2 people · first shared 2024
- 8Clever code is probably the worst code you could write (2023)1 people · 168 points · first shared 2024 · 198 comments on HN
- 9Software Design Principles I Learned the Hard Way1 people · 126 points · first shared 2024 · 88 comments on HN
- 10A simple programming productivity trick: leave work unfinished to reach flow1 people · 3 points · first shared 2023 · discussion on HN
- 11How to burnout a software engineer, in 3 easy steps (2023)1 people · 3 points · first shared 2024 · discussion on HN
- 12How instagram scaled to 14 million1 people · first shared 2023
- 13How facebook scaled memcached1 people · first shared 2024
- 14Homepage1 people · first shared 2025
What HN people wrote when they linked it
realprimoh · 2025-01-06
Engineer's Codex is great: https://read.engineerscodex.com/
bruckie · 2026-07-01
One reason there's no Perforce support for Gerrit/Rietveld is that Google doesn't use those tools for changes to code that's stored in Piper. Instead, they use Critique:
- https://abseil.io/resources/swe-book/html/ch19.html
- https://read.engineerscodex.com/p/how-google-takes-the-pain-out-of
I haven't found anything external that's as good, and am astounded that GitHub's incredibly lackluster PR review tooling is acceptable to most people. If anyone is aware of something in Critique's league, I'd love to hear about it!
shahzaibmushtaq · 2024-12-17
> the app that helps you to track your reading and choose which book to read next based on your mood and favorite topics and themes.
If these requirements are constant then one woman dev team is sufficient until the requirements become thick enough to handle with 2 hands.
And Pinterest reached 11 million users with 6 engineers, if interested https://read.engineerscodex.com/p/how-pinterest-scaled-to-11-million
newsoftheday · 2025-12-18
Agreed.
https://read.engineerscodex.com/p/how-one-line-of-code-caused-a-60
When 10K LOC AI PR's are being created, sometimes by people who either don't understand the code or haven't reviewed the code their trying to submit; the 60 million dollar failure line is potentially lying in wait.
hardwaresofton · 2025-07-30
Note that FDB can support other paradigms on top of KV
https://foundationdb.github.io/fdb-record-layer/SQL_Reference.html
Also IIRC Apple uses FDB at tremendous scale:
https://read.engineerscodex.com/p/how-apple-built-icloud-to-store-bill…
dang · 2024-08-17
I've changed the URL from https://read.engineerscodex.com/p/good-programmers-worry-about-data now. Urgh spammers.
There was a wave of this substack spam a couple months ago and I suppose this is the same bad actor starting up again.
jerbear4328 · 2024-03-14
Actually, Apple does this for iCloud! They use FoundationDB[1] to store billions of databases, one for each user (plus shared or global databases).
See: https://read.engineerscodex.com/p/how-apple-built-icloud-to-store-bill…
Discussed on HN at the time: https://news.ycombinator.com/item?id=39028672
[1]: https://github.com/apple/foundationdb https://en.wikipedia.org/wiki/FoundationDB
pixl97 · 2024-03-05
When most people talk about serving thousands and maybe millions of requests per second, Meta talks about billions of requests per second.
https://read.engineerscodex.com/p/how-facebook-scaled-memcached
fiddlerwoaroof · 2024-01-20
Yeah, at the other end of the scale, it sounds like Apple is now managing exabytes: https://read.engineerscodex.com/p/how-apple-built-icloud-to-store-bill…
This is pretty mind-boggling to me.
yedava · 2024-01-18
Earlier today, this[1] was on the HN front page, a blog post on how Meta processes trillions of serverless functions. All that impressive tech exists for one single reason - massive surveillance at scale.
[1] https://read.engineerscodex.com/p/meta-xfaas-serverless-functions-expl…