Share this page!

Enter URL or ID to Unroll

You can paste full URL like: https://x.com/threadreaderapp/status/1644127596119195649
or just the ID like: 1644127596119195649

How to get URL link on X (Twitter) App

  1. On the Twitter thread, click on or icon on the bottom
  2. Click again on or Share Via icon
  3. Click on Copy Link to Tweet
  4. Paste it above and click "Unroll Thread"!
  5. More info at Twitter Help
Patrick McKenzie Profile picture
@patio11
Aug 12, 2019 • 8 tweets • 2 min read • Read on X
In the category of "It's obvious that there are huge chunks of the economy which need one SFBA-startup quality workflow web app", I give you blend.com , which did that for mortgage origination at banks / credit unions / independent mortgage originators.
It's one of those magically mundane things. The business process here is extremely well-understood; the actual front end and backend processes in the US for mortgage origination are, and this is a technical term, a roaring pyroclastic tire fire.
I went through Blend's white labeled process while trying to get pre-approval to hopefully help a family member out, and literally sent a human two emails "Sorry only have 15 minutes so no possible way this is done today" "Erm ignore the last I think it's ready for you."
This is helped by me being preternaturally organized but sufficient data entry for a mortgage application being collectable in 15 minutes is pretty stunning to me, even with all of the documents ready to go.
If you want to read about mortgage origination and understand why "Hmm this seems like a frontend-heavy web application that one could reasonably deliver in a hackathon" is not coextensive with the actual solution, see
amazon.com/Digitally-Tran…

(Disclaimer: read critically.)
A non-obvious challenge here is that the most important consumer for a home mortgage is not obviously the person buying the house, it is the GSE or other financial system entity which is going to securitize the mortgage.

They have *much* more exacting requirements.
And, structurally, they will *never* talk to the person buying the house, the bank that person has the down payment at, the HR department certifying that that person is gainfully employed, etc etc, *but* they have a lot of very specific questions for *all* of these people.
And so the mortgage loan originator has to have all their paperwork together and pre-reviewed prior to sending it over to the securitizing party.

And if they don't? Well, then they're at substantial risk of either eating the home loan or carrying it on their books for 7+ years.

• • •

Missing some Tweet in this thread? You can try to force a refresh
　

Keep Current with Patrick McKenzie

Patrick McKenzie Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @patio11

Patrick McKenzie Profile picture
Dec 30, 2025
In many domains a generalist who is good at AI and puts an hour or two into something will be three to four sigma from the mean entrant into a support / escalation / etc inbox.

Mitchell has an example from bug reports; I can easily imagine examples from e.g. financial issues.
I think *once* when doing advocacy work for people with banking/credit problems I ran into someone who had an organized call / letter log and so could cleanly generate a timeline that the financial institution could match up with their own files (and obligations).
Try it if you don't believe me but if you give AI a bunch of unstructured input like most people's impressionistic account of how this has been so frustrating dealing with the bank, they will frequently redigest it into "Here's a timeline with bullet points."

That is *useful.*
Read 12 tweets
Patrick McKenzie Profile picture
Dec 9, 2025
Considering writing about non-coding LLM workflows a bit in December partially for personal interest and partially so people can see concrete examples of progress / usage.
The one easiest for me to talk about is just a geeky hobby: here's a plastic model and then here is ChatGPT producing a painting reference of ~that model, after a discussion on characterization, color scheme, etc. Image
Image
I honestly love using it in my art projects. Hallucination rate is acceptable given ~wide acceptance criteria in art; like Bob Ross used to say, there are only happy accidents if e.g. its suggested recipe for mixing a teal paint does not actually result in teal immediately.
Read 7 tweets
Patrick McKenzie Profile picture
Nov 5, 2025
If I clipped every good Byrne Hobart or Matt Levine line I’d never get around to writing my own stuff but this from Byrne is too good to not share: Image
An extraordinary fact about finance is that there are some firms which are financial service providers specifically for scams which sometimes, almost as an industrial accident, bafflingly end up in a contractual relationship with a legitimate, successful company.
These underwriters are not necessarily that; some overlevered highly “structured” IPOs of midmarket software businesses should have a non-zero price, and a capitalist should not say they are a scam just because he is not a buyer at that price.
Read 8 tweets
Patrick McKenzie Profile picture
Oct 27, 2025
How much could would you write if you could one-shot 10-100 line shell scripts or similar almost all of the time, in 10 seconds? You would write a stupid amount of code. Who cares if it is disposable? Dispose of it; it's basically free.
"But what if the code is wrong?"

Skill issue, code is free to you. Write a test suite too, designed to be thrown away in under a minute. Write three independent implementations and vote on the answer. etc, etc
"Have you actually done this?" Yeah, to a minor degree, and I'll recount a bit more when I do some writeups about my experience with LLM programming. After a few weeks of climbing the skill curve instead of some direct questions I'd say "Goal: *direct question* You should..."
Read 11 tweets
Patrick McKenzie Profile picture
Oct 22, 2025
Me to financial firm: *address change form*
Financial firm: Is this five digit number a post code?
Me to financial firm: Oh you have asked exactly the right person for geeking out about post codes. Did you know...
Second thoughts: That was not the efficient way to answer.
"Why didn't they know what a post code looks like?"

Because a post code can look like so many things, like 100-0001, 20500, or SW1A 1AA, to use three codes from three nations that all correspond to a particular famous building/complex within them.
A further fun fact: some nations don't customarily use post codes and others don't customarily use addresses, favoring a natural language description of the recipient which is sufficient to get a mail carrier to successfully route to them.
Read 10 tweets
Patrick McKenzie Profile picture
Oct 16, 2025
Still working on a few essays about what I learned on using LLMs for coding but if you want a sneak peak, Complex Systems this week discusses the game I made in some detail.

I’m probably adding one essay to the series on LLMs for taxes.
It feels a bit weird to need to continue saying this, but yes, LLMs are obviously capable of doing material work in production, including in domains where answers are right or wrong, including where there is a penalty for being wrong. Of course they are.
“Why?”

Because a lot of discourse weights people and actors heavily where they cannot be right or wrong in any way that matters, and where correctness does not materially result in a different incentive for them.
Read 6 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

Send Email!

:(