iiinova — where your digital self keeps evolving

Holly Cummins @hollycummins.com · 07/10/2026

Best slide clicker ever (short-circuited jumper cables!) from @marianne-h.bsky.social at @devoxx.com

Holly Cummins @hollycummins.com · 01/10/2026

I hadn't realised Thoughtworks had dropped Cloud Carbon Footprint. Today's speaker at @greenio-podcast.bsky.social recommends SPRUCE (opensourcegreenops.cloud) instead.

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Holly Cummins @hollycummins.com · 01/10/2026

Should we worry about the impact of wind farms on birds? No, we should worry about the impact of cats. And windows. Compared to those two, the impact of wind farms is basically zero. At Green IO London, and learning lots already. @greenio-podcast.bsky.social

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Holly Cummins @hollycummins.com · 04/09/2026

New book alert: _What Happens When You're Not In The Room_, by Jon Berger. I can recommend it, not on the basis of having read it myself (my copy's in the mail), but on the basis that: - people I trust really rate it - Jon supplied me with me nice wine and nice charcuterie at his London book launch

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Holly Cummins @hollycummins.com · 08/07/2026

Captured! @ddoutsiopoulos.bsky.social in action at #RivieraDev, photographing Roberto Cortez

A speaker in a lecture theatre, with a photographer

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Holly Cummins @hollycummins.com · 07/07/2026

Argh. For my seven-demo talk, I use desktops to keep everything tidy. Mac doesn't allow naming desktops, but I arrange them in the order I need them. Then, when I do the live demo, I get lost finding the right window. I thought it was just demo-brain, but no – by default Mac rearranges windows.

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Holly Cummins @hollycummins.com · 01/07/2026

I should add that I don't actually bring my laptop on runs. That would be dangerous. 😎 Well, and it would undo the 'opportunity for deep thinking' benefits of being away from my laptop. But I *do* take notes in the VoiceNotes app on my phone if I have so many good thoughts I worry I'll forget them.

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Holly Cummins @hollycummins.com · 01/07/2026

This is the way. Working while running is the best working.

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Holly Cummins @hollycummins.com · 05/06/2026

At J-Spring, @felienne.bsky.social quoting Martin Luther King, quoting Thoreau, who apparently anticipated much of modern technology: "Improved means to an unimproved end." Maybe it's kind of comforting that complaints from 200 years ago are still relevant in these uncertain times?

A hand-drawn slide, with text "Improved means to an unimproved end."

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Holly Cummins @hollycummins.com · 05/05/2026

Of course I'm not finished my #DevoxxUK talk, I have a whole ... um ... half a day left to go. But I *am* pleased with this slide.

A slide with blobs showing realism, reproducibility, and relevance.

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Holly Cummins @hollycummins.com · 04/05/2026

May the fourth be with you all. 🖤 "That's no moon ... it's our architecture."

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Holly Cummins @hollycummins.com · 15/04/2026

If you saw my talk at #VoxxedAmsterdam, you'll have seen that my Minecraft demo had challenges, because spawned underwater (and if you didn't, it's here: hollycummins.com/quarkus-ridi...). I've now added controls to the Dev UI card so you can reset the spawn point without needing a server restart.

Screencap of the deb UI with the minecraft card

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Holly Cummins @hollycummins.com · 02/01/2026

I love espressos, but sometimes I do wish they lasted a little longer. Yes, I know the clue is in the name. There's a lesson here in how a design can be perfectly optimised for the stated user requirements and yet not satisfy the user's actual hopes.

An empty cup of coffee in a black espresso cup, with a keyboard in the foreground.

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Holly Cummins @hollycummins.com · 26/11/2025

Thank you to @charity.wtf and Martin for the lovely sticker delivery – my laptop has now been thoroughly @honeycomb.io-ised. It is now much pinker 🦄 and rainbow-ier 🌈 and contains lots of wisdom about how to deliver software 💖.

Laptop with slogans including "live in prod or live a lie," "if it hurts do it more," "are you familiar with our lord and saviour feature flags?"

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Holly Cummins @hollycummins.com · 27/10/2025

I don't know how to explain this coincidence if my computer doesn't have (a) self-awareness and (b) a malevolent sense of humour.

A git diff showing :q was accidentally typed on a line containing "vim".

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Holly Cummins @hollycummins.com · 21/10/2025

This looks more like a swimming route than a walking route, Google.

A map with directions showing the route running down a river.

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Holly Cummins @hollycummins.com · 09/10/2025

I didn't have a chance to show this (generated in 13ms with a quarkus + picocli) in my #Devoxx talk:

A grumpy cat meme saying "I ate a Devoxx sandwich/It was awful"

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Holly Cummins @hollycummins.com · 01/10/2025

It's even funnier on a smaller model:

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Holly Cummins @hollycummins.com · 01/10/2025

I just tried to reproduce @janelleshane.com's brilliant "make an LLM apologise for suggesting a giraffe as CEO" experiment. It 100% worked on Ollama. Which is bad, because when I read it I did an involuntary shriek of laughter, and woke a sleeping puppy, and now I won't be able to do more work.

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Holly Cummins @hollycummins.com · 28/08/2025

It's another double win. If you install solar panels on land sheep are currently grazing, not only can the sheep continue to graze there, they're actually *happier* (because of the shade and more diverse vegetation), and they produce more wool. Hmm, is that actually a triple win?

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Holly Cummins @hollycummins.com · 09/07/2025

Guardrail messages:" A Noodle is not a SNAKE". I can't argue with that. Good job I've got guardrails.

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Holly Cummins @hollycummins.com · 02/07/2025

If the first paragraph wasn't enough to give me a big head, ChatGPT's last paragraph would do it. Well, until it got so sycophantic that my teeth started to hurt from the sweetness. ("The machine likes my drawings enough to revert to cliché, mom!")

Text saying "Holly Cummins’s style is playfully confident: quick, clear line-work; clever use of iconography; occasional textures like shading or stippling; and mixing hand-drawn with digital and photo elements. Above all, it's driven by communication, not aesthetics—she prioritizes clarity, audience memory, and narrative flow over artistic perfection. And by owning her “mediocre” drawing chops, she removes barriers and leaves room for fun and relatability
hollycummins.com+3hollycummins.com+3hollycummins.com+3
.

At its heart, her style is a potent reminder: if you can draw a few lines that illustrate your idea, you've done enough—no need for Da Vincian brilliance."

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Holly Cummins @hollycummins.com · 02/07/2025

You know how modern LLMs use flattery to keep you engaged? I promise I actually did have a reason to ask ChatGPT about my drawing style that wasn't vanity, but I'm now basking in the warm glow of synthetic obsequiousness. ("The machine likes my drawings! It really does!")

A selection of Holly's drawings, and text saying "Holly Cummins's drawing style—especially in her conference talks and slide decks—is instantly recognizable for its deliberate simplicity, warmth, and functional expressiveness. Here's a breakdown of her approach:"

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Holly Cummins @hollycummins.com · 27/05/2025

"Fifty years ago, writing software that used as few resources as possible was a necessity. Now, it's more of a luxury. Why? Moore's law. -‪@vasco-veloso.bsky.social‬ and @johanhutting.bsky.social #JNation

A speaker in front of a slide showing hardware costs going down over time

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Holly Cummins @hollycummins.com · 27/05/2025

At #JNation, @alina-yurenko.bsky.social mentioned someone implemented PHP on GraalVM Truffle. Clearly, implementing @codewithrockstar.com on Truffle would be a better use of time. 😬 🎸

Alina in a hall with timber-beamed roof, in front of a slide

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Holly Cummins @hollycummins.com · 26/05/2025

Getting in the right mood for tomorrow's "efficiency & rock 'n roll" keynote at #JNation by reviewing old team photos.

Four developers, including Holly, wearing rocky clothes and holding a guitar.

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Holly Cummins @hollycummins.com · 09/05/2025

I flipped slides too quick for your camera. Here's the right slide :)

Slide saying €12,000 saved by one script for shutting down 12 school’s computers overnight

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Holly Cummins @hollycummins.com · 08/05/2025

I spoke about concurrency at #DevoxxUK. Mostly, I talked about how it gives me headaches. Going to @handle.invalid's session on thread-safe programming to try and fix that. :)

A Bayes' equation for concurrency causing headaches.

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Holly Cummins @hollycummins.com · 24/04/2025

We talk a lot about GenAI causing a dumbing-down. The dumbification actually has two sides: - the deluge of elegant-but-meaningless slop - real people deliberately writing less elegantly, because they don't want their writing to be mistaken for slop

Two buttons meme, "Be Mistaken for an LLM", "Give up em dashes"

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Holly Cummins @hollycummins.com · 24/04/2025

I'm just going to share this again. :)

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Holly Cummins @hollycummins.com · 08/04/2025

I see what you mean. This one is definitely Roberto Cortez, right? 😉

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Holly Cummins @hollycummins.com · 08/04/2025

Hey, don't forget the programmers in unicorn ears. “Can I ask you something?” “Is it why I’m wearing unicorn ears?” “No, it’s whether you have any sound in your presentation.”

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Holly Cummins @hollycummins.com · 07/04/2025

The clever researchers at @inkandswitch.com are working on outstanding challenges of 'collaboration as version control': - authentication and authorization - indexing - schema control #QConLondon

Slide that says

challenges:
- authentication and authorization
- indexing
- schema control

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Holly Cummins @hollycummins.com · 07/04/2025

Alex Good concludes that collaboration as version control gives us - Generic infrastructure (no lockin) - Reduced development complexity - Change management (by definition) ... but the model works best for apps whose purpose is editing media, rather than transactions. #QConLondon

Slides which says
Collaboration as version control gives us
- Generic infrastructure (no lockin)
- Reduced development complexity
- Change management (by definition)

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Holly Cummins @hollycummins.com · 07/04/2025

... but conflicts can be mitigated, by - choosing a winner without requiring manual intervention - 'saving up' conflicts for later - finer-grained + richer data structures, to avoid 'false' conflicts where the same file got updated with things that don't actually conflict #QConLondon

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Holly Cummins @hollycummins.com · 07/04/2025

Alex of @inkandswitch.com points out that Git is *already* a great example of local first. What if (as a terrible starting idea) we used git as a store for *all* application state, for other applications? Answer: in the naive implementation, merge conflicts, all the time. :)

Slide saying Git for app data - the bad idea

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Holly Cummins @hollycummins.com · 07/04/2025

A set of requirements for local-first software: - No spinners - Multi-device - Network optional - Seamless collaboration - Secure and private

A slide saying

- No spinners
- Multi-device
- Network optional
- Seamless collaboration
- Secure and private

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Holly Cummins @hollycummins.com · 07/04/2025

Really great question from Alex Good of @inkandswitch.com at #QConLondon. "How can I write software that collaborates with other computers, without relying on external servers." Doing that has benefits for resiliency, privacy, UX (it's faster), working on planes (it's possible), ...

A speaker in front of a slide that says collaborative software is fragile.

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Holly Cummins @hollycummins.com · 03/04/2025

At #KubeConLondon? Interested in sustainability? Or cost-savings? Or just ... waste-avoidance? I'll be talking about Practical Zombie Hunting this afternoon at 4pm: Level 1 | Hall Entrance N10 | Room F

A slide saying "forgetfulness laziness fear", with pictures of a goldfish, a sloth, and a monster.

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Holly Cummins @hollycummins.com · 03/04/2025

Did a bit better today with my photography. I'm on my waaaay to #KubeCon (and I managed to get up and out of the house in time, which I'm v proud of myself about).

A sunrise with trees and chimneys in the foreground

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Holly Cummins @hollycummins.com · 01/04/2025

This was supposed to be my "yay, I'm at #KubeCon!" morning-photo. But it's a really bad photo, and I didn't find time to post it until the end of the day.

A long tunnel leading to KubeCon at the Excel

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Holly Cummins @hollycummins.com · 31/03/2025

I don't think I've ever had so many upcoming talks with so little international travel:

Contents of https://hollycummins.com/type/talk/, showing 8 upcoming talks, all with British flag icons, for KubeCon, QCon, and Devoxx.

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Holly Cummins @hollycummins.com · 13/03/2025

Allow me to present the eco monkey. It's a bit like the chaos monkey, except it targets zombie servers. - Turn server off. - If someone screams 😱, turn it back on. This is a wonderful opportunity to test DR and resilience! - If no one screams, keep it off, and enjoy all the energy savings 💶 🌳.

A monkey hanging from a tree, holding a rifle

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Holly Cummins @hollycummins.com · 10/03/2025

No one ever says in career fairs "if you become a developer, you'll be able to make yourself laugh every day by making up silly test data. and then forgetting about it until the test fails." It's a total un-advertised perk of the job.

Console output:

[ERROR] Failures:
[ERROR] SharedProfileTestCase.behaviourOverriddenOnCommandLine:46 1 expectation failed.
Response body doesn't match expectation.
Expected: is "Hey Sausage"
Actual: Bonjour Sausage

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Holly Cummins @hollycummins.com · 25/02/2025

I'm posting a bit late, but aaaaages ago @jlengrand.bsky.social gave me dangerous ideas about custom printing, and I took advantage of a Red Hat Recharge Day on Friday to start putting them into action. 😀

Black fabric printed with the Quarkus Duke rockers

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Holly Cummins @hollycummins.com · 03/02/2025

I've said many times, I like how Quarkus's bytecode-injected Log utility saves you from having to do error-prone copy-pastes of the logging declaration. You can't take advantage of it if you're working on Quarkus core itself. 🐢 🐢 🐢 🐢 🐢 🐢 That's a shame, because I just spotted this in my code. 🤦

public class FacadeClassLoader extends ClassLoader implements Closeable {
private static final Logger log = Logger.getLogger(io.quarkus.bootstrap.classloading.QuarkusClassLoader.class);

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