Javier Lopez Fernandez
@javisan81.bsky.social
I love talking about software development.
November 9, 2025 at 1:14 PM
Sobre los sensible defaults de Thoughtworks
www.thoughtworks.com/es-es/insigh...
www.thoughtworks.com/es-es/insigh...
November 6, 2025 at 5:50 PM
Sobre los sensible defaults de Thoughtworks
www.thoughtworks.com/es-es/insigh...
www.thoughtworks.com/es-es/insigh...
🧠 AI is not solving software’s intrinsic problems — it’s amplifying them.
Many believed coding was the only challenge in software. Others blamed human imperfection. But the truth is: software has intrinsic problems that even the best AI can’t fix.
javil.substack.com/p/the-intrin...
Many believed coding was the only challenge in software. Others blamed human imperfection. But the truth is: software has intrinsic problems that even the best AI can’t fix.
javil.substack.com/p/the-intrin...
The intrinsic problems of software
During the last year I've seen a lot of people claiming against AI because it's not able to maintain the code, or the code is a mess or features have been lost. Welcome to software!!
javil.substack.com
September 28, 2025 at 8:13 AM
🧠 AI is not solving software’s intrinsic problems — it’s amplifying them.
Many believed coding was the only challenge in software. Others blamed human imperfection. But the truth is: software has intrinsic problems that even the best AI can’t fix.
javil.substack.com/p/the-intrin...
Many believed coding was the only challenge in software. Others blamed human imperfection. But the truth is: software has intrinsic problems that even the best AI can’t fix.
javil.substack.com/p/the-intrin...
A broken pipeline isn't just an annoyance, it's a signal.
The true measure of a strong culture isn't whether your pipeline ever fails, but how fast you fix it.
Do it quickly:
Detect it, Fix it, Anticipate frequent errors locally
How does your team handle a broken pipeline?
lnkd.in/dUvtPTRd
The true measure of a strong culture isn't whether your pipeline ever fails, but how fast you fix it.
Do it quickly:
Detect it, Fix it, Anticipate frequent errors locally
How does your team handle a broken pipeline?
lnkd.in/dUvtPTRd
LinkedIn
This link will take you to a page that’s not on LinkedIn
lnkd.in
September 20, 2025 at 9:13 AM
A broken pipeline isn't just an annoyance, it's a signal.
The true measure of a strong culture isn't whether your pipeline ever fails, but how fast you fix it.
Do it quickly:
Detect it, Fix it, Anticipate frequent errors locally
How does your team handle a broken pipeline?
lnkd.in/dUvtPTRd
The true measure of a strong culture isn't whether your pipeline ever fails, but how fast you fix it.
Do it quickly:
Detect it, Fix it, Anticipate frequent errors locally
How does your team handle a broken pipeline?
lnkd.in/dUvtPTRd
Tests are fitness functions that warn us about unintentional behaviors we have introduced when changing some parts of the code, breaking old behaviors.
Instead of testing the structure, test behaviors.
javil.substack.com/p/dont-test-...
Instead of testing the structure, test behaviors.
javil.substack.com/p/dont-test-...
Don't test the structure
Tests are fitness functions that warn us about unintentional behaviors we have introduced when changing some parts of the code, breaking old behaviors.
javil.substack.com
July 12, 2025 at 8:05 AM
Tests are fitness functions that warn us about unintentional behaviors we have introduced when changing some parts of the code, breaking old behaviors.
Instead of testing the structure, test behaviors.
javil.substack.com/p/dont-test-...
Instead of testing the structure, test behaviors.
javil.substack.com/p/dont-test-...
Las herramientas de mocking facilitan la creación de stubs, spies y mocks. Cuando empiezas a aprender a hacer tests, te encantan, después de un tiempo las odias y después te das cuenta de que vuelven a ser geniales.
javil.substack.com/p/mocking-li...
javil.substack.com/p/mocking-li...
Mocking libraries are a powerful tool
Mocking tools make it really easy to create stubs, spies, mocks. When you start learning how to test you love them, then after a while you hate them and after that you realize they are great again.
javil.substack.com
July 6, 2025 at 10:47 AM
Las herramientas de mocking facilitan la creación de stubs, spies y mocks. Cuando empiezas a aprender a hacer tests, te encantan, después de un tiempo las odias y después te das cuenta de que vuelven a ser geniales.
javil.substack.com/p/mocking-li...
javil.substack.com/p/mocking-li...
Mistakes in software are opportunities to learn, but it's incredibly stupid to commit a mistake twice.
open.substack.com/pub/javil/p/...
open.substack.com/pub/javil/p/...
Mistakes
Mistakes in software are opportunities to learn, but it's incredibly stupid to commit a mistake twice.
open.substack.com
June 29, 2025 at 11:57 AM
Mistakes in software are opportunities to learn, but it's incredibly stupid to commit a mistake twice.
open.substack.com/pub/javil/p/...
open.substack.com/pub/javil/p/...
En este episodio de Hablando del de Thoughtworks, hablamos con Raffaella Roviglioni, Principal Experience Designer en Thoughtworks Italia, sobre cómo el Product Discovery puede marcar la diferencia entre construir por intuición o por comprensión real.
www.thoughtworks.com/es-ec/insigh...
www.thoughtworks.com/es-ec/insigh...
Claves para un Product Discovery significativo
En este episodio conversamos con Raffaella Roviglioni, sobre cómo el Product Discovery puede marcar la diferencia entre construir por intuición o por comprensi
www.thoughtworks.com
May 19, 2025 at 7:54 PM
En este episodio de Hablando del de Thoughtworks, hablamos con Raffaella Roviglioni, Principal Experience Designer en Thoughtworks Italia, sobre cómo el Product Discovery puede marcar la diferencia entre construir por intuición o por comprensión real.
www.thoughtworks.com/es-ec/insigh...
www.thoughtworks.com/es-ec/insigh...
¿Es posible construir software sin caer en la sobreingeniería?
Hablamos con María Martínez Miralles sobre uno de los grandes desafíos del desarrollo moderno: la complejidad.
Desde diferenciar la complejidad esencial de la accidental hasta hacerlo todo "bien".
www.thoughtworks.com/es-es/insigh...
Hablamos con María Martínez Miralles sobre uno de los grandes desafíos del desarrollo moderno: la complejidad.
Desde diferenciar la complejidad esencial de la accidental hasta hacerlo todo "bien".
www.thoughtworks.com/es-es/insigh...
Navegando la complejidad en el desarrollo de software
¿Es posible construir software sin caer en la trampa de la sobreingeniería?
www.thoughtworks.com
May 8, 2025 at 5:21 PM
¿Es posible construir software sin caer en la sobreingeniería?
Hablamos con María Martínez Miralles sobre uno de los grandes desafíos del desarrollo moderno: la complejidad.
Desde diferenciar la complejidad esencial de la accidental hasta hacerlo todo "bien".
www.thoughtworks.com/es-es/insigh...
Hablamos con María Martínez Miralles sobre uno de los grandes desafíos del desarrollo moderno: la complejidad.
Desde diferenciar la complejidad esencial de la accidental hasta hacerlo todo "bien".
www.thoughtworks.com/es-es/insigh...
The 28th of April in Spain, the whole country was under a power outage. The way the system was restarted, remembered me about the dog-pile effect.
javi-kata.medium.com/dog-pile-eff...
javi-kata.medium.com/dog-pile-eff...
Dog-pile effect
The 28th of April in Spain, the whole country was under a power outage. The way the system was restarted, remembered me about the dog-pile…
javi-kata.medium.com
April 30, 2025 at 4:14 PM
The 28th of April in Spain, the whole country was under a power outage. The way the system was restarted, remembered me about the dog-pile effect.
javi-kata.medium.com/dog-pile-eff...
javi-kata.medium.com/dog-pile-eff...
I exported all my medium articles to substack.
I will also publish there apart from medium.
substack.com/@javilopez1
I will also publish there apart from medium.
substack.com/@javilopez1
Javi lopez | Substack
substack.com
April 26, 2025 at 7:29 AM
I exported all my medium articles to substack.
I will also publish there apart from medium.
substack.com/@javilopez1
I will also publish there apart from medium.
substack.com/@javilopez1
You’ve probably heard this phrase, “We’ll refactor it later”, what do you feel with that?.
Some people don’t trust this statement, so they don’t believe in that promise at all.
And what do you think are the underlying reasons of this feeling?
javi-kata.medium.com/how-to-use-t...
Some people don’t trust this statement, so they don’t believe in that promise at all.
And what do you think are the underlying reasons of this feeling?
javi-kata.medium.com/how-to-use-t...
How to use Tech Debt for development?
You’ve probably heard this phrase, “We’ll refactor it later”, what do you feel with that?. Some people don’t trust this statement, so they…
javi-kata.medium.com
April 18, 2025 at 8:33 AM
You’ve probably heard this phrase, “We’ll refactor it later”, what do you feel with that?.
Some people don’t trust this statement, so they don’t believe in that promise at all.
And what do you think are the underlying reasons of this feeling?
javi-kata.medium.com/how-to-use-t...
Some people don’t trust this statement, so they don’t believe in that promise at all.
And what do you think are the underlying reasons of this feeling?
javi-kata.medium.com/how-to-use-t...
When I ask my mother about the recipe to do anything she makes, her answer usually is just taste it and decide from that.
She is able to do things, receive feedback from her craft, react and change.
Can we do the same when coding?
javi-kata.medium.com/how-does-my-...
She is able to do things, receive feedback from her craft, react and change.
Can we do the same when coding?
javi-kata.medium.com/how-does-my-...
How does my mother cook?
When I ask my mother about the recipe to do anything she makes, her answer usually is just taste it and decide from that.
Can we do the…
javi-kata.medium.com
April 5, 2025 at 3:29 PM
When I ask my mother about the recipe to do anything she makes, her answer usually is just taste it and decide from that.
She is able to do things, receive feedback from her craft, react and change.
Can we do the same when coding?
javi-kata.medium.com/how-does-my-...
She is able to do things, receive feedback from her craft, react and change.
Can we do the same when coding?
javi-kata.medium.com/how-does-my-...
Design is a word that we use to mention the abstract properties inherent to a product, in hardware this usually means to think in design before creating the product. But is software a different beast?.
javi-kata.medium.com/how-much-upf...
javi-kata.medium.com/how-much-upf...
How much upfront design is enough?
Design is a word that we use to mention the abstract properties inherent to a product, in hardware this usually means to think in design…
javi-kata.medium.com
March 22, 2025 at 11:36 AM
Design is a word that we use to mention the abstract properties inherent to a product, in hardware this usually means to think in design before creating the product. But is software a different beast?.
javi-kata.medium.com/how-much-upf...
javi-kata.medium.com/how-much-upf...
Tests are live documentation and as documentation tests need to show the relevant details and to hide the irrelevant details. We want to avoid “the trees won’t let us see the forest” effect.
medium.com/gitconnected...
medium.com/gitconnected...
Too many details in Tests
Tests are live documentation and as documentation tests need to show the relevant details and to hide the irrelevant details. We want to…
medium.com
March 14, 2025 at 6:22 AM
Tests are live documentation and as documentation tests need to show the relevant details and to hide the irrelevant details. We want to avoid “the trees won’t let us see the forest” effect.
medium.com/gitconnected...
medium.com/gitconnected...
You cannot test everything with unit tests, and it’s a bad idea in general to test everything with higher level tests. So, how to find what to test with what?.
levelup.gitconnected.com/when-i-use-i...
levelup.gitconnected.com/when-i-use-i...
When do I use Integration Tests?
You cannot test everything with unit tests, and it’s a bad idea in general to test everything with higher level tests. So, how to find what…
levelup.gitconnected.com
March 9, 2025 at 7:59 PM
You cannot test everything with unit tests, and it’s a bad idea in general to test everything with higher level tests. So, how to find what to test with what?.
levelup.gitconnected.com/when-i-use-i...
levelup.gitconnected.com/when-i-use-i...
How to teach Trunk Based Development?
Small steps and timeboxing are key.
levelup.gitconnected.com
March 3, 2025 at 12:36 PM
Let’s use some simple refactors and the “expand and contract” method to understand how you can do a big breaking change (change an API, interface, etc.) in small backward compatible increments.
levelup.gitconnected.com/expand-and-c...
levelup.gitconnected.com/expand-and-c...
Expand and contract
Let’s use some simple refactors and the “expand and contract” method to understand how you can do a big breaking change (change an API…
levelup.gitconnected.com
February 27, 2025 at 6:39 PM
Let’s use some simple refactors and the “expand and contract” method to understand how you can do a big breaking change (change an API, interface, etc.) in small backward compatible increments.
levelup.gitconnected.com/expand-and-c...
levelup.gitconnected.com/expand-and-c...
How can we work in legacy code in small steps and pushing to main frequently?. Let’s discuss Golden Master technique.
medium.com/gitconnected...
medium.com/gitconnected...
Trunk Based Development and Legacy Code (Golden Master)
How can we work in legacy code in small steps and pushing to main frequently?. Let’s discuss about Golden Master technique.
medium.com
February 25, 2025 at 2:29 PM
How can we work in legacy code in small steps and pushing to main frequently?. Let’s discuss Golden Master technique.
medium.com/gitconnected...
medium.com/gitconnected...
En este podcast de la serie "Hablando de Software" de Thoughtworks conversamos con @rgv.bsky.social, Tech Lead & Tech Coach, y @culoextremo.bsky.social, Senior Software Engineer en Voxel, sobre la industria del videojuego y el desarrollo de software.
www.thoughtworks.com/es-es/insigh...
www.thoughtworks.com/es-es/insigh...
Más allá del código con videojuegos, desarrollo ágil y XP
Conversamos con Ricardo Guzmán Velasco y Ángel Siendones Sillero sobre la relación entre la industria del videojuego y el desarrollo de software.
www.thoughtworks.com
February 24, 2025 at 7:40 AM
En este podcast de la serie "Hablando de Software" de Thoughtworks conversamos con @rgv.bsky.social, Tech Lead & Tech Coach, y @culoextremo.bsky.social, Senior Software Engineer en Voxel, sobre la industria del videojuego y el desarrollo de software.
www.thoughtworks.com/es-es/insigh...
www.thoughtworks.com/es-es/insigh...
How to add a new feature and deploy frequently (every 5 minutes to prod)?.
We can use toggles and branch by abstraction.
medium.com/gitconnected...
We can use toggles and branch by abstraction.
medium.com/gitconnected...
Trunk Based Development, Toggles and Branch by abstraction
How to add a new feature and deploy frequently (every 5 minutes to prod)?.
We can use toggles and branch by abstraction.
medium.com
February 22, 2025 at 9:18 PM
How to add a new feature and deploy frequently (every 5 minutes to prod)?.
We can use toggles and branch by abstraction.
medium.com/gitconnected...
We can use toggles and branch by abstraction.
medium.com/gitconnected...
I love TDD now, but when I started practicing I thought this was not for me, the majority of people who hate TDD think as I thought at the beginning of my journey, what did I discover to continue?.
medium.com/gitconnected...
medium.com/gitconnected...
Why TDD is hard to use?
I love TDD now, but when I started practicing I thought this was not for me, the majority of people who hate TDD think as I thought at the…
medium.com
February 18, 2025 at 2:25 PM
I love TDD now, but when I started practicing I thought this was not for me, the majority of people who hate TDD think as I thought at the beginning of my journey, what did I discover to continue?.
medium.com/gitconnected...
medium.com/gitconnected...