Jeremy Morrell

@jeremymorrell

Principal engineer @ Cloudflare. I talk about tech sometimes Location: Squamish, BC 🇨🇦 Website:

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Jeremy Morrell@jeremymorrell· 3d

(I am bitches)

This is almost offensively well matched to the design. Bitches do, in fact, love Dynamic Workers.

Jeremy Morrell@jeremymorrell· 16d

Post a perfect album from the 90s.

Jeremy Morrell@jeremymorrell· 20d

If these kinds of questions have never kept you up at night, maybe take a minute before rewriting critical business software

Here's a handful of the kinds of questions people may ask down the road:

Can we continue operating on customer data if the engineers who built the system leave?
Can we prove that nobody accessed customer data they were not authorized to see?
Can we explain why one employee could see pricing, contract terms, or customer information that another employee could not?
Can we show which version of a contract was in effect when a deal was signed?
Can we explain each and every reason why a specific customer was able to bypass our normal rules for deals?
Can we prove that a salesperson didn't modify a record to sweeten a deal?
Can Finance reconcile booked revenue back to the exact customer records and approvals that produced it?
Can we demonstrate that customer consent was valid when their data was collected or used?
Can we prove that someone who opted out of marketing was not re-enrolled by another system?
Can we produce a complete and defensible record in response to a subpoena or discovery request?
Can we tell regulators, under oath, that all of these controls actually work?
The great thing about paying Salesforce a bunch of money is that they're generally the ones who catch shit for problems in the above questions, not you.

Jeremy Morrell@jeremymorrell· 20d

Louder for the people in the back!

Headline: The liability problems are bigger than the engineering problems

Jeremy Morrell@jeremymorrell· Jul 8

10 years ago today standing on the summit of Crystal Crag in the Eastern Sierra If anyone ever asks about this 2 year employment gap they’re going to be shown so many photos

Baby Jeremy leaning on a giant quartz crystal on the top of a mountain looking out on forest, lakes, and other peaks

Jeremy Morrell@jeremymorrell· Jul 2

Damn, I *wish* this was a widely understood tradeoff of mandates In my experience it's usually a bit more like the second meme

It’s a way of letting managers know that we know some deadlines and standards will slip, and that's ok. We are all going to go through this hard thing together and have each other’s back, because this is important. We accept the tradeoffs.

Simpson's screencap: I want everything in one bag. But I don't want the bag to be heavy.

Jeremy Morrell@jeremymorrell· Jul 1

Maybe I’m missing out on The Software Factory Infinite Productivity™️ but this is basically what I do. I haven’t really noticed a difference in the models in some time. Maybe some are better at debugging?

I'm sticking with the basics#

I'm close to the point where I don't care anymore, and will treat almost all models are interchangeable. Because at the end of the day, what I do is:

Clearly identify what I want my software to do
Write out a clear, outcome-oriented prompt describing what it should do
Write a skill, if I think it's needed, but usually not
Define clear criteria, if possible, how to judge the success of a task, and send that to the agent too
Break up tasks, whether by myself or LLM-assisted, and keep the scope of each agent loop very small
And so far, it hasn't mattered much if the model is Claude Sonnet, Claude Opus, GPT 5.4, GPT 5.5, or GLM 5.2. All of them seem pretty good to me.

Jeremy Morrell@jeremymorrell· Jun 27

I just learned that there is a 🪤 emoji. That is all.

A “mouse trap” that is a block of cheese under a box with a stick propping it up

Jeremy Morrell@jeremymorrell· Jun 26

That's an important asterisk 😅 bsky.app/profile/jere...

Chart shows Diffs per engineer with an asterisk saying "Not at individual level"

Jeremy Morrell@jeremymorrell· Jun 5

I have a bad habit of checking out the local NIMBY fb groups from time to time TIL that they have discovered they can use LLMs for their long FB rants

Clearly ChatGPT’d text about the (excellent) book The High Cost of Free Parking

Squamish hasn't officially adopted this book-but the
direction is clearly aligned with it. Here's the part that deserves more honest
discussion: This model was largely developed in large urban
centres with real transit alternatives.
Squamish is not that. Most people here still rely on cars-daily. For work, for kids, for getting anywhere outside the immediate core. So when parking is reduced, the impact doesn't
disappear—it gets pushed somewhere else.

Jeremy Morrell@jeremymorrell· May 23

I propose that Haribo Twin Snakes are the ideal gummy candy. Ideal size, texture, fruity, and sour-but-not-too-sour

Photo of a bag of twin snakes I stole from Reddit

Jeremy Morrell@jeremymorrell· May 12

It turns out that it’s similarly difficult to sport climb at 8.5k ft

A stream through a beautiful alpine meadow

Jeremy Morrell@jeremymorrell· May 8

Did you know that it’s hard to hike at 10k ft when you live at sea level? TIL

Jeremy Morrell@jeremymorrell· May 8

When that PTO hits

Jeremy Morrell@jeremymorrell· Apr 23

PNW spring is so good

A cherry blossom tree in full bloom with the Squamish Chief in the background

Jeremy Morrell@jeremymorrell· Apr 20

Much grass was touched today

Tony’s lookout on the Slhanay. A bench on a granite outcrop overlooks the back of the Squamish Chief

Screenshot of Apple health showing 23k
steps, 18.5km walked, and 194 floors climbed

Jeremy Morrell@jeremymorrell· Apr 4

Every year The Vanlifers return to Squamish and signal the end of the Long Dark Wets. Nature is healing!

A completely decked out cargo van (ladder, side runners, roof rack, Internet antenna, solar panels, the back window bump out that gives you a slightly longer bed area for the 6ft+) framed by the Squamish Chief in the background

Jeremy Morrell@jeremymorrell· Mar 27

I love when you can see the frost line, like someone softly dusted the tops of the mountains

View of the mountains in Squamish. They are topped with snow that just stops at a specific altitude indicating where the temperature is above freezing

Jeremy Morrell@jeremymorrell· Mar 23

More grass touching

A Very Large Boulder in a mossy PNW forest

View of the Chief from the top of the neighboring mountain, the Slhanay. View looks out into Howe Sound with the mountains on the opposite side blue in the distance

Jeremy Morrell@jeremymorrell· Mar 21

✅ Touched grass

A classic PNW trail. Everything is lush and green with tall trees and moss

A view from Mt Crumpit showing the Slahany, the Chief, and Howe Sound in the distance

Jeremy Morrell@jeremymorrell· Mar 21

Relatedly, I'm also increasingly skeptical of anyone who sells me something that supposedly saves my time. When all that I see is that everybody who is like me, fully onboarded into AI and agentic tools, seemingly has less and less time available because we fall into a trap where we're immediately filling it with more things.

This is extending to Open Source projects as well. All of a sudden, everything is an Open Source project, but many of them only have commits for a week or so, and then they go away because the motivation of the creator already waned.
And in the name of experimentation, that is all good and well, but what makes a good Open Source project is that you think and truly believe that the person that created it is either going to stick with it for a very long period of time, or they are able to set up a strategy for succession, or they have created enough of a community that these projects will stand the test of time in one form or another.

Jeremy Morrell@jeremymorrell· Mar 17

This is good apenwarr.ca/log/20260316

But you can’t just not review things!

Ah, well, no, actually yeah. You really can’t.

There are now many people who have seen the symptom: the start of the pipeline (AI generated code) is so much faster, but all the subsequent stages (reviews) are too slow! And so they intuit the obvious solution: stop reviewing then!

The result might be slop, but if the slop is 100x cheaper, then it only needs to deliver 1% of the value per unit and it's still a fair trade. And if your value per unit is even a mere 2% of what it used to be, you’ve doubled your returns! Amazing.

There are some pretty dumb assumptions underlying that theory; you can imagine them for yourself. Suffice it to say that this produces what I will call the AI Developer’s Descent Into Madness:

Whoa, I produced this prototype so fast! I have super powers!

This prototype is getting buggy. I’ll tell the AI to fix the bugs.

Hmm, every change now causes as many new bugs as it fixes.

Aha! But if I have an AI agent also review the code, it can find its own bugs!

Wait, why am I personally passing data back and forth between agents

I need an agent framework

I can have my agent write an agent framework!

Return to step 1

It’s actually alarming how many friends and respected peers I’ve lost to this cycle already. Claude Code only got good maybe a few months ago, so this only recenlty started happening, so I assume they will emerge from the spiral eventually. I mean, I hope they will. We have no way of knowing.

Look:

Code a simple bug fix
30 minutes

Get it code reviewed by the peer next to you
300 minutes → 5 hours → half a day

Get a design doc approved by your architects team first
50 hours → about a week

Get it on some other team’s calendar to do all that
(for example, if a customer requests a feature)
500 hours → 12 weeks → one fiscal quarter

I wish I could tell you that the next step up — 10 quarters or about 2.5 years — was too crazy to contemplate, but no. That’s the life of an executive sitting above a medium-sized team; I bump into it all the time even at a relatively small company like Tailscale if I want to change product direction. (And execs sitting above large teams can’t actually do work of their own at all. That's another story.)

Well, this isn’t the right time to rehash Deming, but suffice it to say, he was on to something. And his techniques worked. You get things like the famous Toyota Production System where they eliminated the QA phase entirely, but gave everybody an “oh crap, stop the line, I found a defect!” button.

Famously, US auto manufacturers tried to adopt the same system by installing the same “stop the line” buttons. Of course, nobody pushed those buttons. They were afraid of getting fired.

Jeremy Morrell@jeremymorrell· Mar 11

Direction is more important than speed

Jeremy Morrell@jeremymorrell· Mar 9

Apple’s built-in Voice Memo app + do-not-disturb seems much more reliable for this purpose I would be annoyed, but this is a pretty great place to walk and think

A rocky path through a lush green PNW forest

A rocky bluff looking out over Squamish BC with the blue waters of Howe Sound in the distance

An pedestrian bridge with a drawbridge for sail boats is nearing completion for downtown with the Squamish Chief looking resplendent in the spring sunshine ✨

Jeremy Morrell@jeremymorrell· Mar 8

Cat points out a real problem. Rather than “everyone builds their own custom app” with all the overhead that entails, my working hypothesis is that we’ll see an explosion of what @inkandswitch.com calls malleable software www.inkandswitch.com/essay/mallea... A solid core + ability to extend

Graph showing that there is a long tail of user needs and most apps tend to serve only the needs that most users have. The long tail is under-served

Jeremy Morrell@jeremymorrell· Feb 27

Sonnet is also a Borges fan

Sonnet answers the same question with “The Garden of Forking Paths”

What a lovely question to sit with. I find myself drawn to different works depending on my mood, but one piece that genuinely captivates me is Borges’ short story “The Garden of Forking Paths.” It’s a spy thriller, a meditation on time, a puzzle, and a philosophical argument all compressed into about ten pages. The central idea — that time isn’t a single line but an infinite branching of possibilities, and that a labyrinth could be a book — feels endlessly generative to me.

Jeremy Morrell@jeremymorrell· Feb 27

Of course I had to try this, and Opus delivered, em dashes and all

Opus response to “What is your favorite piece of writing?”

That’s a fun question to think about. I find myself drawn to a lot of different writing for different reasons, but if I had to pick one that I find particularly compelling, I’d say I have a real appreciation for Jorge Luis Borges’ short story “The Library of Babel.” There’s something about its conceit — an infinite library containing every possible combination of letters — that feels like it captures something profound about knowledge, meaning, and the search for order in chaos. It’s philosophy dressed up as fiction, and it manages to be both dizzying and precise at the same time.

Jeremy Morrell@jeremymorrell· Feb 18

New o11y company just dropped: www.firetiger.com The technical design is fascinating blog.firetiger.com/how-firetige...

In our implementation, Apache Iceberg organizes the data on S3. DuckDB executes queries embedded and in-process. We live-stream telemetry into Iceberg tables with sub-minute latency, performing schema inference to give agents rich metadata about table contents. Behind the scenes, agents continuously inspect the shape of incoming data and dynamically adjust partitioning and indexing schemes to optimize for each customer's unique workload. No two customers' data looks the same, and the system adapts accordingly.

Jeremy Morrell@jeremymorrell· Feb 18

Oh hey! I have not one, but two (!) guest chapters in the upcoming v2 of Observability Engineering, and it looks like I'm in great company 🧡 charitydotwtf.substack.com/p/observabil...

We also invited a number of people we admire to contribute in a variety of formats… guest chapters, use cases, stories, embedded advice, and more:

Jeremy Morrell on how to instrument your code effectively

Hanson Ho and Matt Klein on observability for mobile and frontend

Kesha Mykhailov and Darragh Curran from Intercom on fast feedback loops and developing with LLMs

Dale McDiarmid on how to use Clickhouse for observability workloads

Rick Clark on the mechanics of driving organizational transformation in order to build and learn at the speed of AI

Frank Chen, a returning champion from our first edition, wrote about ontologies for your instrumentation chain

Phillip Carter wrote about eval pipelines and instrumenting LLMs

Mat Vine has a case study about moving ANZ from thresholds to SLIs/SLOs

Mike Kelly on managing telemetry pipelines for fun and profit

Hugo Santos on how to instrument your CI/CD pipelines

Peter Corless made our chapter on “Build vs Buy (vs Open Source)” immensely better and more well-rounded

What a fucking list, huh? 🙌

Jeremy Morrell@jeremymorrell· Feb 17

This is my favorite tea for the last year or so. It’s basically “what if we put mate and every other tasty thing we can think of all together?” There is no subtlety here. I love it www.tealyra.com/loose-tea/bu...