Colin PercivalModify

2025-09-01 08:30:00

Amazon's Leadership Principles are famous, not just within Amazon but also in the tech world at large. While they're frequently mocked — including by Amazonians — they're also generally sensible rules by which to run a company. I've been an Amazon customer for over 25 years and an AWS customer for almost 20 years, and also an AWS Hero for 6 years, and while I've never worked for Amazon I feel that I've seen behind the curtain enough to offer some commentary on a few of these principles.

• Customer Obsession: Leaders start with the customer and work backwards. They work vigorously to earn and keep customer trust. Although leaders pay attention to competitors, they obsess over customers.
  Customer Obsession is great, but I often see Amazonians taking this too simplistically: "Start with the customer" doesn't have to mean "ask customers what they want and then give them faster horses". In the early days of AWS I saw a lot of what I call "cool engineering driven" products: When EC2 launched, it wasn't really clear what people would do with it, but it was very cool and it was clear that it could be a big deal in some form, sooner or later. Some time around 2012, the culture in AWS seemed to shift from "provide cool building blocks" to "build what customers are asking for" and in my view this was a step in the wrong direction (mind you, not nearly as much as the ca. 2020 shift to "build what analysts are asking for in quarterly earnings calls").

2025-06-07 03:30:00

I've been maintaining FreeBSD on the Amazon EC2 platform ever since I first got it booting in 2010, but in November 2023 I added to my responsibilities the role of FreeBSD release engineering lead — just in time to announce the availability of FreeBSD 14.0, although Glen Barber did all the release engineering work for that release. While I receive a small amount of funding from Antithesis and from my FreeBSD/EC2 Patreon, it rapidly became clear that my release engineering duties were competing with — in fact, out-competing — FreeBSD/EC2 for my available FreeBSD volunteer hours: In addition to my long list of "features to implement" stagnating, I had increasingly been saying "huh that's weird... oh well, no time to investigate that now". In short, by early 2024 I was becoming increasingly concerned that I was not in a position to be a good "owner" of the FreeBSD/EC2 platform.

2025-03-22 03:00:00

Ten years ago I wrote that it would require someone smarter than me to extract information from the way that Tarsnap splits data into chunks. Well, I never claimed to be the smartest person in the world! Working with Boris Alexeev and Yan X Zhang, I've just uploaded a paper to the Cryptology ePrint Archive describing a chosen-plaintext attack which would allow someone with access to the Tarsnap server (aka me, Amazon, or the NSA) or potentially someone with sufficient ability to monitor network traffic (e.g. someone watching your wifi transmissions) to extract Tarsnap's chunking parameters. We also present both known and chosen plaintext attacks against BorgBackup, and known plaintext attacks against Restic.

And, of course, because Tarsnap is intended to be Online backups for the truly paranoid, I've released a new version of Tarsnap today (version 1.0.41) which contains mitigations for these attacks, bringing us back to "I can't see any computationally feasible attack"; but I'm also exploring possibilities for making the chunking provably secure.

2024-12-04 10:30:00

As an AWS Hero I get free admission to the AWS re:Invent conference; while it's rare that I'm interested in many talks — in previous years I've attended "Advanced" talks which didn't say anything which wasn't already in the published documentation — I do find that it provides a very good opportunity to talk to Amazonians.

While I'm sure many of the things I ask for get filed under "Colin is weird", I know sometimes Amazon does pay attention — at least, once I find the right person to talk to. Since I have quite a list this year, and I know some Amazonians (and maybe even non-Amazonians) may be interested, I figured I might as well post them here.

2024-04-06 23:30:00

There has been a lot of talk about AI recently, and one particular point has received sigificant attention in the tech industry: The cost of training models. According to some insiders — and the market capitalization of NVIDIA — the computing power needed for AI training threatens to upend the entire semiconductor industry. This should not be a surprise: Generalist AI doesn't scale.

Reduced to its essentials, the task of training a size-N model is one of hill-climbing in N-dimensional space. You take O(N) inputs, run them through your model, and after each of them you nudge the model slightly uphill towards the desired responses. You need O(N) inputs because with any less than that the model will overfit — essentially memorizing the specific set of inputs rather than generalizing from them — and for each of these inputs you need to perform O(N) computation since you have N parameters in the model to tune. End result: O(N^2) computation.

2024-02-27 06:45:00

I just announced the availability of FreeBSD 13.3-RC1. This is the first release candidate of FreeBSD 13.3, and if no further issues are reported will be the only release candidate; I would like to start 13.3-RELEASE builds on Friday, with (allowing time for mirrors to update) the release announcement going out on the following Tuesday (March 5th).

This means there's a few days for people to do some last-minute testing and report any problems they find. If you have time to help out with testing, there are two things in particular which I'd like to see get attention:

1. Wifi, especially the iwlwifi driver. Bjoern Zeeb merged a significant number of changes to the wifi and linuxkpi (which is used by iwlwifi) code between BETA3 and RC1. While these changes were tested extensively, it's still a big chunk of code — more than I would normally have wanted merged so late, but it fixed serious stability issues with iwlwifi so I thought it was worth including anyway. But I'll feel much better about the release if I know people have been testing this code.
2. The installer. Most people who test FreeBSD BETAs do it by upgrading existing systems — fair enough, you test what you have. But this means that the installer doesn't get nearly as much testing as running FreeBSD systems get. So if you have a spare system laying around, please download an installer image and make sure that you can install FreeBSD 13.3-RC1! In particular, keep an eye out for any "missing" hardware or error messages about drivers being unable to reserve resources; we had a late fix to the way that ACPI devices reserve resources.