Nicolas Carlo
@nicoespeon.com
🧹 I refactor Legacy Code and build tools to help you do the same!
✏️ understandlegacycode.com
🎩 Mr. Meetup Montréal • Software Crafters / React / TypeScript / Elixir
🍁 guild.host/montreal-tech/network
✏️ understandlegacycode.com
🎩 Mr. Meetup Montréal • Software Crafters / React / TypeScript / Elixir
🍁 guild.host/montreal-tech/network
Pinned
Nicolas Carlo
@nicoespeon.com
· Sep 17
Alright, let's make it official…
I am super-proud to tell you that I have finally published the print version of my book: "Legacy Code: First Aid Kit" 🎉 📕 🥲
I am super-proud to tell you that I have finally published the print version of my book: "Legacy Code: First Aid Kit" 🎉 📕 🥲
For a while, I was using GitUp (gitup.co) for doing most of my git-related stuff
Features I'm looking for:
- Easy to get the big picture
- Easy to navigate quickly (e.g., keyboard shortcuts)
- Easy to "add patch" a few lines of a file
- Easy to rebase a branch (Alt+R) and undo anything (Ctrl+Z)
Features I'm looking for:
- Easy to get the big picture
- Easy to navigate quickly (e.g., keyboard shortcuts)
- Easy to "add patch" a few lines of a file
- Easy to rebase a branch (Alt+R) and undo anything (Ctrl+Z)
GitUp
GitUp is Git the way it should be
gitup.co
January 8, 2026 at 4:27 PM
For a while, I was using GitUp (gitup.co) for doing most of my git-related stuff
Features I'm looking for:
- Easy to get the big picture
- Easy to navigate quickly (e.g., keyboard shortcuts)
- Easy to "add patch" a few lines of a file
- Easy to rebase a branch (Alt+R) and undo anything (Ctrl+Z)
Features I'm looking for:
- Easy to get the big picture
- Easy to navigate quickly (e.g., keyboard shortcuts)
- Easy to "add patch" a few lines of a file
- Easy to rebase a branch (Alt+R) and undo anything (Ctrl+Z)
Reposted by Nicolas Carlo
Temporal is the Date system we always wanted in JavaScript. It's extremely close to being available so Mat Marquis thought it would be a good idea to explain exactly what is better about this new JavaScript date system.
piccalil.li/blog/date-is...
piccalil.li/blog/date-is...
Date is out, Temporal is in
Temporal is the Date system we always wanted in JavaScript. It's extremely close to being available so Mat Marquis thought it would be a good idea to explain exactly what is better about this new JavaScript...
piccalil.li
January 7, 2026 at 3:22 PM
Temporal is the Date system we always wanted in JavaScript. It's extremely close to being available so Mat Marquis thought it would be a good idea to explain exactly what is better about this new JavaScript date system.
piccalil.li/blog/date-is...
piccalil.li/blog/date-is...
It's a nice remote event happening in May!
Got things you'd like to share about working with legacy code? Submit your talk proposals in the CFP and you may become part of the lineup 😉
Got things you'd like to share about working with legacy code? Submit your talk proposals in the CFP and you may become part of the lineup 😉
MenderCon 2026 will happen online, on May 7
📢 If you want to present something related to working with legacy code, the CFP has open!
www.papercall.io/mendercon-2026
FYI, there will be 3 talks alongside open-space discussions. Talks will be recorded and published on YouTube afterwards 😉
📢 If you want to present something related to working with legacy code, the CFP has open!
www.papercall.io/mendercon-2026
FYI, there will be 3 talks alongside open-space discussions. Talks will be recorded and published on YouTube afterwards 😉
PaperCall.io - MenderCon 2026
# Focused Content
A full day focused on modernizing and improving software systems. From the smallest apps to the biggest enterprise monoliths. Find your people and learn here.
# Virtual Unconference...
www.papercall.io
January 7, 2026 at 3:14 PM
It's a nice remote event happening in May!
Got things you'd like to share about working with legacy code? Submit your talk proposals in the CFP and you may become part of the lineup 😉
Got things you'd like to share about working with legacy code? Submit your talk proposals in the CFP and you may become part of the lineup 😉
Reposted by Nicolas Carlo
Great short post from @mheap.dev: michaelheap.com/visibility-i...
It takes practice to deliver the right level of abstraction--too many details are not great.
But surprises are so so bad.
Even if Alice delivers a month later than Bob, people understand why and are more likely to accept it.
It takes practice to deliver the right level of abstraction--too many details are not great.
But surprises are so so bad.
Even if Alice delivers a month later than Bob, people understand why and are more likely to accept it.
Visibility is Velocity
Why visible progress beats speed: how incremental updates build trust, reduce risk, and change how complex product work is perceived.
michaelheap.com
January 7, 2026 at 12:58 PM
Great short post from @mheap.dev: michaelheap.com/visibility-i...
It takes practice to deliver the right level of abstraction--too many details are not great.
But surprises are so so bad.
Even if Alice delivers a month later than Bob, people understand why and are more likely to accept it.
It takes practice to deliver the right level of abstraction--too many details are not great.
But surprises are so so bad.
Even if Alice delivers a month later than Bob, people understand why and are more likely to accept it.
Reposted by Nicolas Carlo
I've seen this passed around a bunch and skimmed it and nodded in agreement (because obviously the new mac OS interface design is bad), but I didn't actually sit down and read the whole thing until just now.
God, it's just brutal.
tonsky.me/blog/tahoe-i...
God, it's just brutal.
tonsky.me/blog/tahoe-i...
It’s hard to justify Tahoe icons
Looking at the first principles of icon design—and how Apple failed to apply all of them in macOS Tahoe
tonsky.me
January 6, 2026 at 2:26 PM
I've seen this passed around a bunch and skimmed it and nodded in agreement (because obviously the new mac OS interface design is bad), but I didn't actually sit down and read the whole thing until just now.
God, it's just brutal.
tonsky.me/blog/tahoe-i...
God, it's just brutal.
tonsky.me/blog/tahoe-i...
Reposted by Nicolas Carlo
🪄 Jan 14th at 6PM: React MTL - Jan 2026
Join fellow Montreal geeks for a night of learning, food, and drinks at Shopify! ⚛️🍕
Falilou Khouma cooks up mobile apps with Expo, and Zoey Moore secures our React apps. 📱🛡️
Check it out 👉 https://guild.host/e/u9y55t
Join fellow Montreal geeks for a night of learning, food, and drinks at Shopify! ⚛️🍕
Falilou Khouma cooks up mobile apps with Expo, and Zoey Moore secures our React apps. 📱🛡️
Check it out 👉 https://guild.host/e/u9y55t
React MTL - Jan 2026
👥 Join us on Discord: discord.gg/kddEWbFhbc
Our wonderful sponsor: Shopify ⭐
\---
Rejoins-nous pour apprendre et échanger avec des développeurs et développeuses React & React Native de Montréal! Comme d'habitude, il y aura de la bonne nourriture et des boissons rafraichissantes!
Join us for an amazing fun evening and meet fellow Montrealer React & React Native geeks! As always, expect delicious food and refreshing drinks!
The talks of this event will be in English. We will have two presentations:
Falilou Khouma will discuss "Cooking mobile apps with React Native + Expo". Falilou is a full-stack developer with experience across the React ecosystem who enjoys building well-designed products and apps, with a strong passion for creativity.
Zoey Moore will talk about "Security in React applications - how to avoid common vulnerabilities". Zoey is a Full Stack Developer and Modern Web specialist.
guild.host
January 5, 2026 at 2:52 PM
🪄 Jan 14th at 6PM: React MTL - Jan 2026
Join fellow Montreal geeks for a night of learning, food, and drinks at Shopify! ⚛️🍕
Falilou Khouma cooks up mobile apps with Expo, and Zoey Moore secures our React apps. 📱🛡️
Check it out 👉 https://guild.host/e/u9y55t
Join fellow Montreal geeks for a night of learning, food, and drinks at Shopify! ⚛️🍕
Falilou Khouma cooks up mobile apps with Expo, and Zoey Moore secures our React apps. 📱🛡️
Check it out 👉 https://guild.host/e/u9y55t
Let's go 2026!
Starting with 2 events this month:
- Software Crafters MTL this Wed: guild.host/software-cra...
- React MTL next week: guild.host/events/react...
Starting with 2 events this month:
- Software Crafters MTL this Wed: guild.host/software-cra...
- React MTL next week: guild.host/events/react...
Software Crafters Montréal Upcoming Events | Guild
Discuss: slack.softwarecrafters.org (channel #loc\_montréal)
Past meetups notes: github.com/Software-Crafters-Montreal/meetups
Contact: cr
guild.host
January 5, 2026 at 2:53 PM
Let's go 2026!
Starting with 2 events this month:
- Software Crafters MTL this Wed: guild.host/software-cra...
- React MTL next week: guild.host/events/react...
Starting with 2 events this month:
- Software Crafters MTL this Wed: guild.host/software-cra...
- React MTL next week: guild.host/events/react...
I had a blast to present at JS Heroes in 2025. The organization is incredible 👌
I'm not submitting in 2026 because I'll have other priorities, but I can encourage you in doing so. Especially if you are in Europe 😉
I'm not submitting in 2026 because I'll have other priorities, but I can encourage you in doing so. Especially if you are in Europe 😉
We're entering the last hours of the CFP! 😱
Keep in mind the form closes at midnight Romania time, 11:00 CET so you can enjoy the New Year celebrations after wrapping up your proposal! 🎉
Happy New Year everyone! ❤️
Keep in mind the form closes at midnight Romania time, 11:00 CET so you can enjoy the New Year celebrations after wrapping up your proposal! 🎉
Happy New Year everyone! ❤️
⏳ The Call for Papers is closing soon!
If you haven’t submitted your proposal yet, you still have 3 days left to take your chance at joining us as a speaker at #JSHeroes 2026. 🌟
👉 jsheroes.io/speak
#TechEvent #TechConference #WebDev #TechInnovation
If you haven’t submitted your proposal yet, you still have 3 days left to take your chance at joining us as a speaker at #JSHeroes 2026. 🌟
👉 jsheroes.io/speak
#TechEvent #TechConference #WebDev #TechInnovation
December 31, 2025 at 6:35 PM
I had a blast to present at JS Heroes in 2025. The organization is incredible 👌
I'm not submitting in 2026 because I'll have other priorities, but I can encourage you in doing so. Especially if you are in Europe 😉
I'm not submitting in 2026 because I'll have other priorities, but I can encourage you in doing so. Especially if you are in Europe 😉
The Honey Files Expose Major Fraud!
YouTube video by MegaLag
www.youtube.com
December 31, 2025 at 3:12 AM
Reposted by Nicolas Carlo
Introducing Flint: a fast, friendly linter.
Flint is an experimental linter made to validate several hypotheses: hybrid linting, streamlined rich configuration, thorough docs & plugins, and tooling coordination.
Expect to hear more about Flint over the next month. ❤️🔥
www.flint.fyi/blog/introdu...
Flint is an experimental linter made to validate several hypotheses: hybrid linting, streamlined rich configuration, thorough docs & plugins, and tooling coordination.
Expect to hear more about Flint over the next month. ❤️🔥
www.flint.fyi/blog/introdu...
Introducing Flint
[Experimental] A fast, friendly linter. ❤️🔥
www.flint.fyi
December 30, 2025 at 9:40 PM
Introducing Flint: a fast, friendly linter.
Flint is an experimental linter made to validate several hypotheses: hybrid linting, streamlined rich configuration, thorough docs & plugins, and tooling coordination.
Expect to hear more about Flint over the next month. ❤️🔥
www.flint.fyi/blog/introdu...
Flint is an experimental linter made to validate several hypotheses: hybrid linting, streamlined rich configuration, thorough docs & plugins, and tooling coordination.
Expect to hear more about Flint over the next month. ❤️🔥
www.flint.fyi/blog/introdu...
Canada is so nice that if you can't take time to go ice skating, it brings the rink right in front of your door, driveway, sidewalk, road… ⛸️ ❄️ 🤣
#FreezingRain
#FreezingRain
December 30, 2025 at 3:38 PM
Canada is so nice that if you can't take time to go ice skating, it brings the rink right in front of your door, driveway, sidewalk, road… ⛸️ ❄️ 🤣
#FreezingRain
#FreezingRain
Reposted by Nicolas Carlo
Something something great minds thinking alike... #refactoring #evolutionarydesign
Different articulations of a mental model will click with different people, but those models tend to be much more alike than they are different. :)
Different articulations of a mental model will click with different people, but those models tend to be much more alike than they are different. :)
December 18, 2025 at 2:02 PM
Something something great minds thinking alike... #refactoring #evolutionarydesign
Different articulations of a mental model will click with different people, but those models tend to be much more alike than they are different. :)
Different articulations of a mental model will click with different people, but those models tend to be much more alike than they are different. :)
Reposted by Nicolas Carlo
it is the season of giving, so here is my gift to you:
`git checkout -`
you're welcome
`git checkout -`
you're welcome
December 16, 2025 at 5:06 PM
it is the season of giving, so here is my gift to you:
`git checkout -`
you're welcome
`git checkout -`
you're welcome
Reposted by Nicolas Carlo
Have you made any plans for 2026 yet? How about giving yourself or a friend something to look forward to...
...because we have exciting news before the winter break: Registration is now open for SoCraTes UK 2026!
Register: socratesuk.org/tickets.html
...because we have exciting news before the winter break: Registration is now open for SoCraTes UK 2026!
Register: socratesuk.org/tickets.html
SoCraTes UK - Tickets
Join us for another year of SoCraTes UK happening on June 18th - 21st! The event is hosted at Milton Hill House, UK which is surrounded by 22 acres of landscaped grounds and forest, delivering…
socratesuk.org
December 16, 2025 at 9:00 AM
Have you made any plans for 2026 yet? How about giving yourself or a friend something to look forward to...
...because we have exciting news before the winter break: Registration is now open for SoCraTes UK 2026!
Register: socratesuk.org/tickets.html
...because we have exciting news before the winter break: Registration is now open for SoCraTes UK 2026!
Register: socratesuk.org/tickets.html
Reposted by Nicolas Carlo
With the year wrapping up, nostalgia starts to kick in as we think back on all the inspiring talks we listened to. ✨
💡 If you’re looking for some tech insights to end the year with - or simply want to get nostalgic with us - check out all the 2025 talks here: bit.ly/3GEBiUf.
#JSHeroes #TechEvent
💡 If you’re looking for some tech insights to end the year with - or simply want to get nostalgic with us - check out all the 2025 talks here: bit.ly/3GEBiUf.
#JSHeroes #TechEvent
December 16, 2025 at 1:30 PM
With the year wrapping up, nostalgia starts to kick in as we think back on all the inspiring talks we listened to. ✨
💡 If you’re looking for some tech insights to end the year with - or simply want to get nostalgic with us - check out all the 2025 talks here: bit.ly/3GEBiUf.
#JSHeroes #TechEvent
💡 If you’re looking for some tech insights to end the year with - or simply want to get nostalgic with us - check out all the 2025 talks here: bit.ly/3GEBiUf.
#JSHeroes #TechEvent
Hey, my talk "6 Safe Refactorings for Untested Legacy Code" that I gave at @confooca.bsky.social 2025 is available online!
How cool is that? 😄
So here it is: I'm presenting you with 6 moves you can use in VS Code to refactor untested code ✊
www.youtube.com/watch?v=5YEm...
How cool is that? 😄
So here it is: I'm presenting you with 6 moves you can use in VS Code to refactor untested code ✊
www.youtube.com/watch?v=5YEm...
6 Safe Refactorings for Untested Legacy Code — Nicolas Carlo
YouTube video by ConFoo Developer Conference
www.youtube.com
December 15, 2025 at 3:25 PM
Hey, my talk "6 Safe Refactorings for Untested Legacy Code" that I gave at @confooca.bsky.social 2025 is available online!
How cool is that? 😄
So here it is: I'm presenting you with 6 moves you can use in VS Code to refactor untested code ✊
www.youtube.com/watch?v=5YEm...
How cool is that? 😄
So here it is: I'm presenting you with 6 moves you can use in VS Code to refactor untested code ✊
www.youtube.com/watch?v=5YEm...
Reposted by Nicolas Carlo
Legacy code doesn’t just run, it speaks 😃
Steve Richey reminds us that code carries history and intent, and preserving that makes maintenance more meaningful.
… It's also a great reminder of why it's often a good idea to fix existing software *progressively* 😄
www.youtube.com/watch?v=tGWO...
Steve Richey reminds us that code carries history and intent, and preserving that makes maintenance more meaningful.
… It's also a great reminder of why it's often a good idea to fix existing software *progressively* 😄
www.youtube.com/watch?v=tGWO...
MenderCon 2022 - Code is Communication with Steve Richey
YouTube video by MenderCon
www.youtube.com
December 15, 2025 at 3:15 PM
Legacy code doesn’t just run, it speaks 😃
Steve Richey reminds us that code carries history and intent, and preserving that makes maintenance more meaningful.
… It's also a great reminder of why it's often a good idea to fix existing software *progressively* 😄
www.youtube.com/watch?v=tGWO...
Steve Richey reminds us that code carries history and intent, and preserving that makes maintenance more meaningful.
… It's also a great reminder of why it's often a good idea to fix existing software *progressively* 😄
www.youtube.com/watch?v=tGWO...
Been reading about Airbnb devs migrating their frontend test suite from Enzyme to RTL
When you are at this scale, migrations pose an interesting challenge…
Especially since many devs are constantly adding to the codebases 😄 ☕
product.hubspot.com/blog/migrate...
When you are at this scale, migrations pose an interesting challenge…
Especially since many devs are constantly adding to the codebases 😄 ☕
product.hubspot.com/blog/migrate...
Moving Mountains: How We Migrated from Enzyme to React Testing Library
How we migrated 76,000 tests from Enzyme to React Testing Library, modernizing our stack and allowing teams to ship changes with more confidence.
product.hubspot.com
December 12, 2025 at 4:27 PM
Been reading about Airbnb devs migrating their frontend test suite from Enzyme to RTL
When you are at this scale, migrations pose an interesting challenge…
Especially since many devs are constantly adding to the codebases 😄 ☕
product.hubspot.com/blog/migrate...
When you are at this scale, migrations pose an interesting challenge…
Especially since many devs are constantly adding to the codebases 😄 ☕
product.hubspot.com/blog/migrate...
Reposted by Nicolas Carlo
Feeling overwhelmed by a tangled legacy codebase?
@nicoespeon.com offers 7 concrete techniques to help: from incremental refactoring to testing strategies and maintenance best practices.
This talk gives actionable advice for devs navigating tech debt!
🎥 www.youtube.com/watch?v=6KUU...
@nicoespeon.com offers 7 concrete techniques to help: from incremental refactoring to testing strategies and maintenance best practices.
This talk gives actionable advice for devs navigating tech debt!
🎥 www.youtube.com/watch?v=6KUU...
MenderCon 2021 - Nicolas Carlo on 7 Techniques to Tame a Legacy Codebase
YouTube video by MenderCon
www.youtube.com
December 12, 2025 at 3:05 PM
Feeling overwhelmed by a tangled legacy codebase?
@nicoespeon.com offers 7 concrete techniques to help: from incremental refactoring to testing strategies and maintenance best practices.
This talk gives actionable advice for devs navigating tech debt!
🎥 www.youtube.com/watch?v=6KUU...
@nicoespeon.com offers 7 concrete techniques to help: from incremental refactoring to testing strategies and maintenance best practices.
This talk gives actionable advice for devs navigating tech debt!
🎥 www.youtube.com/watch?v=6KUU...
Reposted by Nicolas Carlo
I think Marian is doing a great job of explaining how people learn can refactoring, the stages you go through and what it looks like. It's helping me design training for developers open.substack.com/pub/changeth...
A Clearer Path: Refining the Model for Better Clarity and Use
Another iteration for clearer language cleaner visuals.
open.substack.com
December 11, 2025 at 2:07 PM
I think Marian is doing a great job of explaining how people learn can refactoring, the stages you go through and what it looks like. It's helping me design training for developers open.substack.com/pub/changeth...
Reposted by Nicolas Carlo
Splitting a messy monolithic codebase into microservices can be tempting… but it’s rarely easy 😅
Sarah Dutkiewicz walks us through strategies and pitfalls when doing so. This talk is useful for teams undertaking large-scale architecture change!
🎥 www.youtube.com/watch?v=oqXn...
Sarah Dutkiewicz walks us through strategies and pitfalls when doing so. This talk is useful for teams undertaking large-scale architecture change!
🎥 www.youtube.com/watch?v=oqXn...
MenderCon 2024 - Sarah Dutkiewicz on From Legacy Monolith to Microservices via Event Storming
YouTube video by MenderCon
www.youtube.com
December 10, 2025 at 6:04 PM
Splitting a messy monolithic codebase into microservices can be tempting… but it’s rarely easy 😅
Sarah Dutkiewicz walks us through strategies and pitfalls when doing so. This talk is useful for teams undertaking large-scale architecture change!
🎥 www.youtube.com/watch?v=oqXn...
Sarah Dutkiewicz walks us through strategies and pitfalls when doing so. This talk is useful for teams undertaking large-scale architecture change!
🎥 www.youtube.com/watch?v=oqXn...
Reposted by Nicolas Carlo
Ever stared at a legacy codebase and wondered: “What is going on here?”
In this talk, Federico helps you navigate that complexity by identifying recurring "idioms" in code, then uses those to guide refactoring or migration
🎥 www.youtube.com/watch?v=z2Px...
More legacy-code wisdom coming soon…
In this talk, Federico helps you navigate that complexity by identifying recurring "idioms" in code, then uses those to guide refactoring or migration
🎥 www.youtube.com/watch?v=z2Px...
More legacy-code wisdom coming soon…
Federico Tomassetti on Deciphering Legacy Codebases Using Idioms | MenderCon 2025
YouTube video by MenderCon
www.youtube.com
December 9, 2025 at 2:07 PM
Ever stared at a legacy codebase and wondered: “What is going on here?”
In this talk, Federico helps you navigate that complexity by identifying recurring "idioms" in code, then uses those to guide refactoring or migration
🎥 www.youtube.com/watch?v=z2Px...
More legacy-code wisdom coming soon…
In this talk, Federico helps you navigate that complexity by identifying recurring "idioms" in code, then uses those to guide refactoring or migration
🎥 www.youtube.com/watch?v=z2Px...
More legacy-code wisdom coming soon…
Reposted by Nicolas Carlo
👀 If you're wondering what #JSHeroes 2026 will be like...here's a glimpse of the good vibes, inspiring talks, and amazing people from last year ✨
🎬 youtu.be/iPeXgjX_mg0
#TechConference #TechEvent #TechInnovation #WebDev
🎬 youtu.be/iPeXgjX_mg0
#TechConference #TechEvent #TechInnovation #WebDev
Aftermovie - JSHeroes 2025
Enjoy the aftermovie for the 7th edition of JSHeroes, the biggest JavaScript conference in Romania.
JSHeroes is a community-driven event, organised by the JSHeroes Community.
https://jsheroes.io
youtu.be
December 9, 2025 at 2:07 PM
👀 If you're wondering what #JSHeroes 2026 will be like...here's a glimpse of the good vibes, inspiring talks, and amazing people from last year ✨
🎬 youtu.be/iPeXgjX_mg0
#TechConference #TechEvent #TechInnovation #WebDev
🎬 youtu.be/iPeXgjX_mg0
#TechConference #TechEvent #TechInnovation #WebDev
Reposted by Nicolas Carlo
I am really enjoying having some time between contracts at the moment... I just wrote an article about the test desiderata - this has been on my mind to write about for several years at this point! coding-is-like-cooking.info/2025/12/test...
Test Desiderata 2.0 - Coding Is Like Cooking
Kent Beck is one of the original authors of JUnit, an open source tool that kick-started a huge shift in programmer behaviour that I and others have found immensely valuable. In 2019 he published his ...
coding-is-like-cooking.info
December 8, 2025 at 1:47 PM
I am really enjoying having some time between contracts at the moment... I just wrote an article about the test desiderata - this has been on my mind to write about for several years at this point! coding-is-like-cooking.info/2025/12/test...