Simon Eskildsen
sirupsen.com · Personal blog · on HN since 2010
Simon Eskildsen, an infrastructure engineer, writes on databases, performance, napkin math, and learning, with posts on MySQL, TCP, and neural networks.
What HN saysCommenters value his napkin math approach to performance and link his neural network from scratch tutorial and his Minimum Viable Airtable idea.
40HN people shared it
11linked it in comments
44stories submitted
1.9Kstory points
12 months agolast shared
2010people per year2026
Most-shared posts
- 1Using checksums to verify syncing 100M database records5 people · 7 points · first shared 2021 · discussion on HN
- 2Napkin4 people · first shared 2020
- 3Shitlist Driven Development (2016)3 people · 416 points · first shared 2020 · 137 comments on HN
- 4Neural network from scratch3 people · 214 points · first shared 2022 · 38 comments on HN
- 5Increase HTTP performance by fitting in the initial TCP slow start window3 people · 104 points · first shared 2021 · 6 comments on HN
- 6Adjacent Possible: Peeking into the Future3 people · 6 points · first shared 2020 · discussion on HN
- 7Careful Trading Complexity for 'Improvements'3 people · 5 points · first shared 2021 · discussion on HN
- 8MySQL transactions per second vs. fsyncs per second (2020)2 people · 134 points · first shared 2020 · 52 comments on HN
- 9Get started right with RVM2 people · 69 points · first shared 2010 · 21 comments on HN
- 10My journey to the International Olympiad in Informatics2 people · 47 points · first shared 2012 · 10 comments on HN
- 11Scaling Causal's Spreadsheet Engine: From Maps to Arrays2 people · 26 points · first shared 2022 · 4 comments on HN
- 12How I read by Simon Hørup Eskildsen2 people · 3 points · first shared 2018 · discussion on HN
- 13Minimum viable airtable2 people · first shared 2018
- 14Why Docker Is Not Yet Succeeding Widely in Production1 people · 502 points · first shared 2015 · 280 comments on HN
- 15Why I'm glad my iPhone broke1 people · 91 points · first shared 2013 · 103 comments on HN
What HN people wrote when they linked it
Sverigevader · 2025-11-22
Great comment! I was inspired by this article https://every.to/superorganizers/how-to-build-a-learning-machine-29965… about Simon Eskildsen, which led me to his blog https://sirupsen.com/, which then led me to create https://juliusrobert.site for myself. It's not a traditional blog per se but it checks some boxes and I have the same quote as you do here as a reason to do this https://simonwillison.net/2024/Dec/22/link-blog/#writing-about-things-…
Sirupsen · 2022-01-05
Great questions, I struggled with this part the most when I was learning it.
`.grad` is set by `autograd` when calling `backward()`
Probably the easiest way to understand this is to play a bit with `.grad` and `backward()` on their own, with the first code sample in the `autograd` section [1].
[1]: https://sirupsen.com/napkin/neural-net#automagically-computing-the-slo…
Kagerjay · 2018-03-15
Glad to see this company get more funding. Last year I ported all of our companys excel and access files over to airtable. Currently tweaking with their API to work with a MS-SQL database using amazon Lambda and RDS at the moment.
Their API documentation is fantastic, some of the best I've seen as well. They even have some of the best case studies for workflow management as well, posted on their blog, for setting up a relational database management setup in different use cases.
As a user who's also part of their alpha-test program, its exciting to see all the changes they made this year. They added blocks which lets you add app-like integrations such as forms, kanban, maps integration, page designer (think of mailmerge for word) etc. I personally have only dabbled in about half the things offered here, but its crazy how many things you can do with airtable.
I also wrote a popular excel VBA script for airtable too, for bulk downloading and renaming images found here on their forum. https://community.airtable.com/t/bulk-image-downloader-and-renamer-usi…
Airtable has lots of potential use cases for startup apps as well, I highly suggest reading this article from a philosophical standpoint. http://sirupsen.com/minimum-viable-airtable/
skeptrune · 2025-10-19
I read this as napkin math[1] for Kube and thoroughly enjoyed. You can only find the important numbers relative to performance and scaling by trying to accomplish some kind of goal. Benchmarks are mostly bikeshedding.
[1]: https://sirupsen.com/napkin
kkukshtel · 2025-10-01
This reminds me of this idea of "Minium Viable Airtable" that I think is apt:
https://sirupsen.com/minimum-viable-airtable
darthShadow · 2025-07-19
sargstuff · 2023-07-29
server/client data sync example problem : https://sirupsen.com/napkin/problem-9
cinntaile · 2021-07-19
There's a monthly newsletter dedicated to napkin math. He hasn't made one in a few months for some reason, but judging from his tweets he's working on a new one. You can also practice on the old ones of course. https://sirupsen.com/napkin/
varunsaini · 2021-01-05
Simon from Shopify has this awesome newsletter to talk about some of these things.
https://sirupsen.com/napkin/problem-14-using-checksums-to-verify/
gmcabrita · 2020-05-23
Simon Eskildsen has a monthly newsletter called Napkin Math[0] entirely dedicated to practicing practical real-world Fermi problems like these.
[0] - https://sirupsen.com/napkin/
kaylarose · 2011-04-18
Take bricestacey's advice, use RVM. I was in the same boat as you when getting started with Ruby - it seemed like I was always fighting with gems and other dependencies - "there has to be a better way!", I thought. And there was...
I read this article[1] and it changed my life.
[1]http://sirupsen.com/get-started-right-with-rvm/