Hacker News: andrewljohnson

New comment by andrewljohnson in "Why Software Factories Fail (or: harness engineering is not enough)"

andrewljohnson — Fri, 24 Jul 2026 03:22:10 +0000

You either need to quit or keep your head down, I can’t tell which.

New comment by andrewljohnson in "Costco is the anti-Amazon"

andrewljohnson — Sat, 04 Jul 2026 18:51:58 +0000

This sounds like a constraint I model in my bin packing optimization routine.

New comment by andrewljohnson in "Costco is the anti-Amazon"

andrewljohnson — Sat, 04 Jul 2026 01:41:26 +0000

Bin packing is theoretically NP Hard but practically solved all the time on real world datasets.

New comment by andrewljohnson in "Pre-2022 Books"

andrewljohnson — Sun, 21 Jun 2026 00:51:52 +0000

Pro-tip - the older it is, the more likely it is to be good.

New comment by andrewljohnson in "Throwing AI-generated walls of text into conversations"

andrewljohnson — Fri, 22 May 2026 03:16:54 +0000

This sounds like a broken culture to me. Teams shouldn't tolerate it... it is both harmful and contagious.

New comment by andrewljohnson in "Throwing AI-generated walls of text into conversations"

andrewljohnson — Fri, 22 May 2026 03:14:41 +0000

A lot of organizations right now are dealing with the "Claude says..." problem.

It's not that you should never include any AI generated text in a conversation with other engineers, but you mostly shouldn't.

AI is a tool to help you understand/debug/review yourself, but you shouldn't be conferring authority to your AI (because it doesn't understand anything and is often wrong in the text it spews), and you shouldn't be running an AI for other people, they should run it themselves.

New comment by andrewljohnson in "LLMs corrupt your documents when you delegate"

andrewljohnson — Sat, 09 May 2026 18:25:53 +0000

You can just look at the diff when you do a pull request, no prayer needed, and if you want it to be “surgical” in that way, your prompt (and agents.md) can be specific.

You can also unit test the function to better assure behavior didn’t change.

New comment by andrewljohnson in "LLMs Corrupt Your Documents When You Delegate"

andrewljohnson — Sat, 09 May 2026 18:17:15 +0000

I’m fine with bulk review, it just has to get reviewed before a merge. You don’t need to review the LLM output as you work except as it aids you to work.

New comment by andrewljohnson in "LLMs corrupt your documents when you delegate"

andrewljohnson — Sat, 09 May 2026 16:01:44 +0000

LLM editing should be done to produce deterministic output.

That is, the LLM should produce a diff, and the user should accept the diff. It seems like a bad pattern to just tell the LLM to edit any long document without that sort of visibility. Same goes for prose as for code.

New comment by andrewljohnson in "GameStop makes $55.5B takeover offer for eBay"

andrewljohnson — Mon, 04 May 2026 20:09:26 +0000

I am familiar with all the particulars, check my HN profile ;)

New comment by andrewljohnson in "GameStop makes $55.5B takeover offer for eBay"

andrewljohnson — Mon, 04 May 2026 15:12:41 +0000

eBay already had warehousing ops, I assume larger than tcgplayer’s.

Last year, eBay shut down tcgplayer’s only fulfillment facility in Rochester, NY and switched to using eBay’s facility in Kentucky.

New comment by andrewljohnson in "Ask HN: How to solve the cold start problem for a two-sided marketplace?"

andrewljohnson — Mon, 20 Apr 2026 20:00:58 +0000

For my marketplace, I was friends with someone who could make it look like not a ghost town for the supply (an established game store with lots of trading cards in stock). Then, we struggled to get more sellers. Then, we found channels to get selllers, which were basically software systems we could build integrations with. The integrations de-risked the proposition for sellers enough to get more traction. Eventually, if you have growing volume, the supplyside just starts coming on its own mostly, and you focus on retaining sellers and growing buyers.

For your marketplace, you could bring the supply-side by Fedexing stuff when you don't have a carrier. You'll have to lose money on the initial shipment, until you can route the jobs to the supplyside. This assumes you think the typical use case for this isn't smuggling.

The amount of jobs may be low enough at first that you can be like "You said Cairo to London, that will be $N." Then, if you can fill the job manually by finding someone somehow, then you add them to the platform and they do the job. If not, you send a prepaid mailing package with a Fedex label to the recipient and they ship it easily, and you subsidize it so it seems like a great deal to them.

Limiting geography seems like a good approach too.

New comment by andrewljohnson in "Hyperscalers have already outspent most famous US megaprojects"

andrewljohnson — Sat, 18 Apr 2026 05:18:40 +0000

You could argue that compute was a decisive factor in World War II even (used in code breaking and designing nuclear weapons).

New comment by andrewljohnson in "Launch HN: Palus Finance (YC W26): Better yields on idle cash for startups, SMBs"

andrewljohnson — Fri, 06 Mar 2026 18:55:12 +0000

We use Mercury’s treasury account to get yields on cash, and what appeals to me is it is easy to manage. I don’t have to worry about setting up processes to move money around and it’s integrated with my bank account, and we wouldn’t want to switch even for a higher yield… the operational burden is more important to us than yield.

I think the yield is about 3.2% based on how we set it up to be as liquid as possible. We could have accepted less liquidity for more like 3.8%

New comment by andrewljohnson in "Ask HN: Who is hiring? (March 2026)"

andrewljohnson — Mon, 02 Mar 2026 21:29:55 +0000

Mana Pool | Senior/Principal Software Engineer | Full-Time | Remote (US) | 135k-200k USD

We make the market for Magic cards. If you play Magic, we'd love to see you apply.

https://manapool.com/jobs/software-engineer

New comment by andrewljohnson in "Statement from Dario Amodei on our discussions with the Department of War"

andrewljohnson — Fri, 27 Feb 2026 03:04:38 +0000

This doesn’t read to me like it was personally written by one person. It’s not Dario we should read this as being written by, it’s Anthropic as an entity.

New comment by andrewljohnson in "NanoChat – The best ChatGPT that $100 can buy"

andrewljohnson — Mon, 13 Oct 2025 18:24:44 +0000

the shakespeare code tuned a little with different training data does a good job of generating Magic The Gathering commander decks

New comment by andrewljohnson in "Implementing a Foil Sticker Effect"

andrewljohnson — Mon, 01 Sep 2025 20:52:43 +0000

This is neat, I have a simple CSS effect that I apply to foil cards on my Magic card marketplace site, but I have wondered what it would take to replicate all the different foil effects that a Magic card can come in to be both more varied and more true to life, in a performant way that fits into my CRUD svelte UX.

New comment by andrewljohnson in "A bug saved the company"

andrewljohnson — Tue, 26 Aug 2025 15:11:21 +0000

This almost exact thing happened with me with a hiking app I used to make. We had a 7-day trial when you started the app, but we shipped a release that broke this and made all the paid features immediately paywalled. This led to a big increase in sales and we got rid of the trial forever.

It’s possible that our trial might have worked better if it were like modern iOS trials that start charging you after a certain period, but ours just let you use the paid features for 7 days and then lapsed, and it stifled sales. My theory was people urgently needed the paid features (mostly to download maps for a coming trip) so the trial got in the way of them paying right away.

New comment by andrewljohnson in "Adding a feature because ChatGPT incorrectly thinks it exists"

andrewljohnson — Mon, 07 Jul 2025 19:12:21 +0000

The same could be said for books about writing, like Williams or Strunk and White. The trick is to not apply what you learn indiscriminately.