John Kerr
@developkerr.com
Over 15 years of building software in start-ups. Hobbyist game developer. #SAFC until it kills me.
https://developkerr.com
https://boarded.app
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https://developkerr.com
https://boarded.app
https://add-comments.com
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John Kerr
@developkerr.com
· Nov 4
Always been terrible at #buildinpublic - the building part is fine but I always end up doing it in a bunker. Seems to be a nice community building over here though so let's see if I can do a better job in 🦋. Here are a few of my recent projects... 🧵
From a commercial perspective I understand exactly why they've done it, but as somebody who has used Duolingo every day for 10 years I find the switch from hearts to energy making me question whether I want to continue. Awful UX. Unfortunately I'm weak and the gamification has its claws in deep.
September 30, 2025 at 6:28 AM
From a commercial perspective I understand exactly why they've done it, but as somebody who has used Duolingo every day for 10 years I find the switch from hearts to energy making me question whether I want to continue. Awful UX. Unfortunately I'm weak and the gamification has its claws in deep.
Biggest lie in tech (ever?) is the "intelligence" in artificial intelligence when talking about LLMs. Probability based predictive text is not intelligence. Don't see how that ever changes where LLMs are concerned.
September 19, 2025 at 8:38 AM
Biggest lie in tech (ever?) is the "intelligence" in artificial intelligence when talking about LLMs. Probability based predictive text is not intelligence. Don't see how that ever changes where LLMs are concerned.
20 unsuccessful attempts to defeat Lace last night. Defeat her first attempt this morning. Sure there's a psychological reason for this as it's every bloody time #Silksong
September 7, 2025 at 10:03 AM
20 unsuccessful attempts to defeat Lace last night. Defeat her first attempt this morning. Sure there's a psychological reason for this as it's every bloody time #Silksong
Random person likes old post on LinkedIn
Looks over to "My Network" and there's a connection request from the same person
Every time
Looks over to "My Network" and there's a connection request from the same person
Every time
July 10, 2025 at 8:32 AM
Random person likes old post on LinkedIn
Looks over to "My Network" and there's a connection request from the same person
Every time
Looks over to "My Network" and there's a connection request from the same person
Every time
100% this. Typing speed was never the limiting factor.
Amusing outcome of "vibe coding" wave with AI (by people who have not written software professionally before)
Seeing the speedrun of why software development REALLY is hard
(it was never about writing code - even though most non-dev folks assumed it must have been!)
Seeing the speedrun of why software development REALLY is hard
(it was never about writing code - even though most non-dev folks assumed it must have been!)
May 30, 2025 at 1:26 PM
100% this. Typing speed was never the limiting factor.
There's a special place in hell for Temu adverts on Duolingo
May 3, 2025 at 7:21 AM
There's a special place in hell for Temu adverts on Duolingo
Read @tmaker.io blog yesterday and it home. I've often felt frustrated by the people I'm working with and their refusal to tackle problems head on. I'd never really thought of it in these terms, but I realise now that I'm high action and frustrated by low action people. Explains a lot.
April 25, 2025 at 10:32 AM
Read @tmaker.io blog yesterday and it home. I've often felt frustrated by the people I'm working with and their refusal to tackle problems head on. I'd never really thought of it in these terms, but I realise now that I'm high action and frustrated by low action people. Explains a lot.
Some pretty wild stuff in this. Does make you question how useful LLMs actually are though. SDR content is relatively low stakes, transient and measurable. Code is high stakes and only measurable when defective. Suspect the 80/20 rule to bite hard for LLMs & somewhere in that 20% is true usefulness.
a16z and Benchmark-backed 11x has been claiming customers it doesn’t have
a16z and Benchmark-backed 11x has been claiming customers it doesn’t have
Last year, AI-powered sales automation startup 11x appeared to be on an explosive growth trajectory. However, nearly two dozen sources – including investors, current and former employees – tell TechCrunch that the company has experienced financial struggles, largely of its own making. Numerous people in the U.S. and U.K. told TechCrunch that the situation has […]
tcrn.ch
March 25, 2025 at 9:51 AM
Some pretty wild stuff in this. Does make you question how useful LLMs actually are though. SDR content is relatively low stakes, transient and measurable. Code is high stakes and only measurable when defective. Suspect the 80/20 rule to bite hard for LLMs & somewhere in that 20% is true usefulness.
Prediction: Software certification is going to become a much bigger industry in the AI era. It won't take many security issues from AI generated code before businesses lose faith and start mandating a higher level of compliance before trusting companies with their data.
March 12, 2025 at 5:28 PM
Prediction: Software certification is going to become a much bigger industry in the AI era. It won't take many security issues from AI generated code before businesses lose faith and start mandating a higher level of compliance before trusting companies with their data.
Messed up a refactor, tackled too much at once and ended up working in a branch across 48 commits. Seriously, how do people work like that, merging in a tonne of code all at once and releasing periodically. First time I've actually been nervous putting code live in years. Back to CD now 😅
March 7, 2025 at 2:38 PM
Messed up a refactor, tackled too much at once and ended up working in a branch across 48 commits. Seriously, how do people work like that, merging in a tonne of code all at once and releasing periodically. First time I've actually been nervous putting code live in years. Back to CD now 😅
Was discussing this the other day. I can see lots of systems like this making it into the wild and relying on senior developers to fix. However, companies replacing junior roles with LLMs will also break the pipeline of junior to senior dev, thus making seniors a scarce and expensive commodity.
February 16, 2025 at 2:24 PM
Was discussing this the other day. I can see lots of systems like this making it into the wild and relying on senior developers to fix. However, companies replacing junior roles with LLMs will also break the pipeline of junior to senior dev, thus making seniors a scarce and expensive commodity.
Usual consistency from me. Startup life + side projects + game dev. Not making any money from those side projects but learning all the time, despite moving towards veteran status and close to 20 years in the industry 👴🏻
December 31, 2024 at 12:29 PM
Usual consistency from me. Startup life + side projects + game dev. Not making any money from those side projects but learning all the time, despite moving towards veteran status and close to 20 years in the industry 👴🏻
A good thread. The least productive team I ever worked in was also the largest team. The premise of scaling to hundreds of devs (human or artificial) being a good thing is rooted in the misconception that software engineering is production based, whereas it's actually design based.
I see so much FUD about the future of sw engineering, mostly from non-devs. Along the lines of “soon anyone can spin off AI agents in bulk that act as hundreds of devs.”
A false premise. Just open your airline app that is built by ~hundreds of devs over 10+ years
A false premise. Just open your airline app that is built by ~hundreds of devs over 10+ years
December 21, 2024 at 8:14 AM
A good thread. The least productive team I ever worked in was also the largest team. The premise of scaling to hundreds of devs (human or artificial) being a good thing is rooted in the misconception that software engineering is production based, whereas it's actually design based.
An interesting question from a recent podcast appearance around culture eating strategy for breakfast. In my experience there's nothing more toxic to culture than bad strategy. Optimists asking realists to take a leap of faith will lead to a culture clash.
www.linkedin.com/posts/qasim-...
www.linkedin.com/posts/qasim-...
Qasim Asghar on LinkedIn: #culture #strategy #businesssuccess
"Culture eats strategy for breakfast" - a classic quote, but does it hold up?
I recently sat down with John Kerr to discuss this very topic. While he…
www.linkedin.com
December 16, 2024 at 10:20 AM
An interesting question from a recent podcast appearance around culture eating strategy for breakfast. In my experience there's nothing more toxic to culture than bad strategy. Optimists asking realists to take a leap of faith will lead to a culture clash.
www.linkedin.com/posts/qasim-...
www.linkedin.com/posts/qasim-...
Tell me you work in tech without telling me you work in tech
My top song of 2024 was "Oh Shit"
My top song of 2024 was "Oh Shit"
December 4, 2024 at 1:31 PM
Tell me you work in tech without telling me you work in tech
My top song of 2024 was "Oh Shit"
My top song of 2024 was "Oh Shit"
Been working my way through My Perfect Console by @simonparkin.bsky.social. Great listen and premise. Love the interviews with indie game developers and he's spoken to some of the greats. My games would be: Super Mario World, Champ Manager 97/98, Skyrim, Stardew Valley and Untitled Goose Game 😎
November 27, 2024 at 8:55 PM
Been working my way through My Perfect Console by @simonparkin.bsky.social. Great listen and premise. Love the interviews with indie game developers and he's spoken to some of the greats. My games would be: Super Mario World, Champ Manager 97/98, Skyrim, Stardew Valley and Untitled Goose Game 😎
I was asked yesterday "what metrics can we track so that tech is accountable?"
For me, the most important things by far are how often you ship and what the defect rate is.
Even things like page load time & uptime likely correlate with defect rate.
What is everybody else tracking?
For me, the most important things by far are how often you ship and what the defect rate is.
Even things like page load time & uptime likely correlate with defect rate.
What is everybody else tracking?
November 23, 2024 at 8:57 AM
I was asked yesterday "what metrics can we track so that tech is accountable?"
For me, the most important things by far are how often you ship and what the defect rate is.
Even things like page load time & uptime likely correlate with defect rate.
What is everybody else tracking?
For me, the most important things by far are how often you ship and what the defect rate is.
Even things like page load time & uptime likely correlate with defect rate.
What is everybody else tracking?
Feel the next challenge for @bsky.app is to make it really easy for companies and news providers to move over. Probably the only reason I'm still using the other app at all. Basically once Sunderland AFC have an official presence here I can fully migrate!
November 21, 2024 at 5:50 PM
Feel the next challenge for @bsky.app is to make it really easy for companies and news providers to move over. Probably the only reason I'm still using the other app at all. Basically once Sunderland AFC have an official presence here I can fully migrate!
6+ calls with a huge customer to bottom out their requirements and ensure we understand what we need to support. Customer eventually signs after 6 months. Start changing the product to accommodate and make good progress.
Customer: Actually...
Ok, we'll accommodate that too.
Customer: Actually...
Customer: Actually...
Ok, we'll accommodate that too.
Customer: Actually...
a soccer field with a stadium in the background that says the day radio stand
Alt: People moving goalposts across a soccer field
media.tenor.com
November 21, 2024 at 9:52 AM
6+ calls with a huge customer to bottom out their requirements and ensure we understand what we need to support. Customer eventually signs after 6 months. Start changing the product to accommodate and make good progress.
Customer: Actually...
Ok, we'll accommodate that too.
Customer: Actually...
Customer: Actually...
Ok, we'll accommodate that too.
Customer: Actually...
Fresh set of Ernie Ball Slinky strings and it's a completely different guitar 🎸 Always love their packaging too, they make guitar strings look as enticing as Wonka chocolate bars.
November 17, 2024 at 3:16 PM
Fresh set of Ernie Ball Slinky strings and it's a completely different guitar 🎸 Always love their packaging too, they make guitar strings look as enticing as Wonka chocolate bars.
Some days in startups are just... there are definitely easier ways to make money 😩 5 hours of receiving feedback today that we have no bandwidth for 😬 At least they care enough to give feedback, but it's rough to spend all day saying no. Still... yes might be easier to say but no is easier to do.
November 12, 2024 at 9:55 PM
Some days in startups are just... there are definitely easier ways to make money 😩 5 hours of receiving feedback today that we have no bandwidth for 😬 At least they care enough to give feedback, but it's rough to spend all day saying no. Still... yes might be easier to say but no is easier to do.
Think @bsky.app starter packs are a genius addition to the product. Completely takes the hassle out of moving to a new network, and gives you an opportunity to join a new community without needing to post endlessly until people start to notice you. Bravo to the product team 👏
November 8, 2024 at 2:55 PM
Think @bsky.app starter packs are a genius addition to the product. Completely takes the hassle out of moving to a new network, and gives you an opportunity to join a new community without needing to post endlessly until people start to notice you. Bravo to the product team 👏
Not liking the change to how you boost XP in Duolingo. The 3x multiplier is great but for years I've always left myself one lesson away from an XP boost ready for the next day and it no longer works 😭 Can't be pulling the rug on us Duolingo OGs with the 3000 day streaks!
November 7, 2024 at 7:16 AM
Not liking the change to how you boost XP in Duolingo. The 3x multiplier is great but for years I've always left myself one lesson away from an XP boost ready for the next day and it no longer works 😭 Can't be pulling the rug on us Duolingo OGs with the 3000 day streaks!