rahimnathwani

Joined 14 years ago

Karma
16,455
Submissions
7,104
Member since
Mar 9
I've lived in San Francisco since 2019.

2010-2019 I lived in China.

Before that I lived in London, where I was born.

My personal web site: https://encona.com/

Random tools: https://tools.encona.com/

Other random stuff about me:

- English is my native language, but I also speak (to varying degrees of fluency) Mandarin, Gujarati and Spanish.

- My career so far has been a mix of startups/cofounding, big tech (I was a PM at Amazon and at Google), and exec roles.

- I'm a qualified accountant (CIMA), have two undergrad degrees (one in CS) and an MBA (sorry!).

- I got married in 2012 and our son was born in 2016 (I spend a lot of time thinking about how best to raise him to be a capable and kind adult)

Email: rahim AT encona DOT com

LinkedIn: http://www.linkedin.com/in/rahimnathwani

X: https://x.com/rahimNathwani/

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Recent submissions

Comment · 2 days ago
Do they work well as a replacement for a monitor when you're travelling?
Comment · 6 days ago
I don't know what records I'm missing. I usually only know of the existence of a record once I've received it.
Comment · 6 days ago
"The work falls outside normal scope of the person's job."

Maybe in some cases, but not in this case with this agency (SFUSD).

The responses I've received so far from SFUSD (over several years) were each from someone whose whole job is/was dealing with public records requests.

One of the requests that was refused was for a Google Slides deck that was visible to all of SFUSD's ~10000 employees.

Comment · 6 days ago
Some agencies have a different tactic: go really slowly.

I sent a public records request to my local school district on March 9th 2026.

They responded on 19th March 2026 saying they'd respond on in late April.

Since then, every month they've sent an email with some small portion of the records, with a PDF letter saying they'll send a follow up a month later.

I've received 8 of those responses so far, and there's no indication when, if ever, I will have received all the records responsive to my request.

Comment · 6 days ago
In the UK, 'pavement' doesn't refer to any paved road, but to what Americans call a 'sidewalk'.

Bicycles are ridden on the road, not the pavement.

Sometimes people ride bicycles on the pavement, but doing so with a long piece of wood would be very dangerous indeed.

Comment · 8 days ago
Yes, the reward needs to include both correctness AND the Brier loss. Sorry if that wasn't clear from my comment. I was focused on the bit OP said was missing.
Comment · 9 days ago
Comment · 9 days ago
If you found this interesting, you should read section 5 of this article to learn about how LLMs can be trained so that they're good at confidence scoring: https://magazine.sebastianraschka.com/i/217935364/51-on-cali...

OP says that LLMs were never scored against correctness. But that's an assumption about the optimization process.

This is sort of right:

- pretraining scores on next token, and says nothing about confidence

- RLHF and RLVR scores are binary (1=preferred/correct, 0=worse/incorrect) and the feedback doesn't do anything to push the weights in a direction that improves calibration/confidence

BUT you can ask the model to output its confidence, and then train it to be more correct. RLCR (mentioned in the article I linked above) adds a Brier penalty to the reward, so the model's performance isn't just measured on % correctness. (Presumably TypeSafeAI's RLCD is similar to RLCR, but they haven't published anything about it.)

This eliminates the "always say 30%" loophole OP mentioned. The Brier penalty, (q-c)^2, punishes a forecaster who ignores instance-level information. For example if we have a model that's right 60% of the time, it could use one of these strategies to give its confidence:

  Strategy A, always say 0.6:
  When right (60% of the time): (0.6-1)^2 = 0.16
  When wrong (40% of the time): (0.6-0)^2 = 0.36
  Expected penalty: 0.6×0.16 + 0.4×0.36 = 0.24

  Strategy B: the model can tell its answers apart. Half are 'easy' (right 90% of the time) and half are 'hard' (right 30% of the time), which still averages to 60%. It says 0.9 on easy ones and 0.3 on hard ones:
  Easy: 0.9×(0.1)^2 + 0.1×(0.9)^2 = 0.09
  Hard: 0.3×(0.7)^2 + 0.7×(0.3)^2 = 0.21
  Expected penalty: (0.09+0.21)/2 = 0.15
Both strategies are perfectly calibrated (60% is both the average confidence and thje average % of time it's right), but B gets a lower penalty. Of course these are not actual strategies used by LLMs. But I'm just trying to say why training can push the model toward optimizing instance-specific confidence.
Comment · 9 days ago
"There were no end entity certificates issued out of the affected CA’s."

This seems like a weird statement given that anyone can issue certificates out of the affected CAs.

Comment · 10 days ago
Imagine I have a link of this format:

https://cf.metaaiusercontent.com/q3-revenue-review-7b1e42f0

No one can guess that URL. The q3-revenue-review-7b1e42f0 part is only ever shared with the Meta's server (protected by TLS).

Now imagine the URL is instead:

https://q3-revenue-review-7b1e42f0.cf.metaaiusercontent.com/

The first step for my computer to open that link is to do a DNS query, which immediately shares the entire URL (minus the `https://` and the `/`) with my ISP's DNS server (and anyone sniffing traffic along the path, as DNS queries are usually sent in plain text).

Comment · 11 days ago
Comment · 11 days ago
capable, tenacious, kind

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