Darius Cosden 🧑🏻💻
@cosden.dev
Teaching React at @cosdensolutions · 170k subs · Building an AI learning platform
I'm realizing a lot of developers don't fully understand how React works
Even when I make videos showing how it is, and using the official docs as support, they still don't get it
So here's a couple of the most important things you need to know about how React works
Even when I make videos showing how it is, and using the official docs as support, they still don't get it
So here's a couple of the most important things you need to know about how React works
October 28, 2025 at 11:00 AM
I'm realizing a lot of developers don't fully understand how React works
Even when I make videos showing how it is, and using the official docs as support, they still don't get it
So here's a couple of the most important things you need to know about how React works
Even when I make videos showing how it is, and using the official docs as support, they still don't get it
So here's a couple of the most important things you need to know about how React works
Today I start filming the "React Fundamentals" course on Cosden Code
This will cover all the essentials like JSX, components, state, hooks, etc
It won't cover 3rd party libraries (RQ, forms, state management) since those will be in other courses
What topics do you want to see?
This will cover all the essentials like JSX, components, state, hooks, etc
It won't cover 3rd party libraries (RQ, forms, state management) since those will be in other courses
What topics do you want to see?
October 27, 2025 at 11:01 AM
Today I start filming the "React Fundamentals" course on Cosden Code
This will cover all the essentials like JSX, components, state, hooks, etc
It won't cover 3rd party libraries (RQ, forms, state management) since those will be in other courses
What topics do you want to see?
This will cover all the essentials like JSX, components, state, hooks, etc
It won't cover 3rd party libraries (RQ, forms, state management) since those will be in other courses
What topics do you want to see?
Just added the first video lessons to my new platform Cosden Code (coming soon)
The videos are SO GOOD. Literally my best work
First course is on design patterns in React, and I promise you, you haven't seen most of these patterns
I'm beyond excited to launch this
The videos are SO GOOD. Literally my best work
First course is on design patterns in React, and I promise you, you haven't seen most of these patterns
I'm beyond excited to launch this
October 24, 2025 at 9:56 AM
Just added the first video lessons to my new platform Cosden Code (coming soon)
The videos are SO GOOD. Literally my best work
First course is on design patterns in React, and I promise you, you haven't seen most of these patterns
I'm beyond excited to launch this
The videos are SO GOOD. Literally my best work
First course is on design patterns in React, and I promise you, you haven't seen most of these patterns
I'm beyond excited to launch this
In React, the smaller your components are, the better
Building small components makes your apps simple, maintainable, and scalable
You can still have complexity, but it will be much easier to manage with small pieces
The best code is simple code
Building small components makes your apps simple, maintainable, and scalable
You can still have complexity, but it will be much easier to manage with small pieces
The best code is simple code
October 23, 2025 at 9:57 AM
In React, the smaller your components are, the better
Building small components makes your apps simple, maintainable, and scalable
You can still have complexity, but it will be much easier to manage with small pieces
The best code is simple code
Building small components makes your apps simple, maintainable, and scalable
You can still have complexity, but it will be much easier to manage with small pieces
The best code is simple code
I'm currently trying out Windsurf coming from Cursor
First impressions, it's mostly the same, but the tab complete is inferior
You really feel it when trying to tab complete a lot of files
Pricing is better though so idk
First impressions, it's mostly the same, but the tab complete is inferior
You really feel it when trying to tab complete a lot of files
Pricing is better though so idk
October 22, 2025 at 3:02 PM
I'm currently trying out Windsurf coming from Cursor
First impressions, it's mostly the same, but the tab complete is inferior
You really feel it when trying to tab complete a lot of files
Pricing is better though so idk
First impressions, it's mostly the same, but the tab complete is inferior
You really feel it when trying to tab complete a lot of files
Pricing is better though so idk
React tip for state updates
Instead of:
setCount(count + 1)
Do:
setCount(prev => prev + 1)
The function version always gets the current state. Helps avoid bugs with stale values
Instead of:
setCount(count + 1)
Do:
setCount(prev => prev + 1)
The function version always gets the current state. Helps avoid bugs with stale values
October 20, 2025 at 10:04 AM
React tip for state updates
Instead of:
setCount(count + 1)
Do:
setCount(prev => prev + 1)
The function version always gets the current state. Helps avoid bugs with stale values
Instead of:
setCount(count + 1)
Do:
setCount(prev => prev + 1)
The function version always gets the current state. Helps avoid bugs with stale values
Quick debugging tip for React devs
Instead of:
console.log(user)
console.log(posts)
Do this:
console.log({ user, posts })
You get labeled output in the console. Makes it way easier to track what's what when you have multiple logs
Instead of:
console.log(user)
console.log(posts)
Do this:
console.log({ user, posts })
You get labeled output in the console. Makes it way easier to track what's what when you have multiple logs
October 17, 2025 at 10:04 AM
Quick debugging tip for React devs
Instead of:
console.log(user)
console.log(posts)
Do this:
console.log({ user, posts })
You get labeled output in the console. Makes it way easier to track what's what when you have multiple logs
Instead of:
console.log(user)
console.log(posts)
Do this:
console.log({ user, posts })
You get labeled output in the console. Makes it way easier to track what's what when you have multiple logs
One of the weirdest patterns in React is the abandon render pattern
This is when you call a state updater function directly in the body of the component as its rendering
React will abandon the render and start again with a new value
Here's an example
This is when you call a state updater function directly in the body of the component as its rendering
React will abandon the render and start again with a new value
Here's an example
October 16, 2025 at 10:04 AM
One of the weirdest patterns in React is the abandon render pattern
This is when you call a state updater function directly in the body of the component as its rendering
React will abandon the render and start again with a new value
Here's an example
This is when you call a state updater function directly in the body of the component as its rendering
React will abandon the render and start again with a new value
Here's an example
When I use AI to code, it either helps me solve a very specific hard bug or it helps me not have to write a bunch of new code that follows the same patterns
Outside of that, it just gets in my way
No matter the model or the tool that I use
Outside of that, it just gets in my way
No matter the model or the tool that I use
October 15, 2025 at 2:56 PM
When I use AI to code, it either helps me solve a very specific hard bug or it helps me not have to write a bunch of new code that follows the same patterns
Outside of that, it just gets in my way
No matter the model or the tool that I use
Outside of that, it just gets in my way
No matter the model or the tool that I use
React 19.2 just introduced the useEffectEvent hook
This hook finally fixes one of the biggest problems that developers face when it comes to effects and dependency arrays
Finally, we can put this issue to rest and focus on shipping actual features
Here's how it works
This hook finally fixes one of the biggest problems that developers face when it comes to effects and dependency arrays
Finally, we can put this issue to rest and focus on shipping actual features
Here's how it works
October 15, 2025 at 9:56 AM
React 19.2 just introduced the useEffectEvent hook
This hook finally fixes one of the biggest problems that developers face when it comes to effects and dependency arrays
Finally, we can put this issue to rest and focus on shipping actual features
Here's how it works
This hook finally fixes one of the biggest problems that developers face when it comes to effects and dependency arrays
Finally, we can put this issue to rest and focus on shipping actual features
Here's how it works
So are we all moving away from Next.js now?
October 14, 2025 at 2:57 PM
So are we all moving away from Next.js now?
I'm currently filming a course on design patterns in React
This is by far the best course on this topic. Nothing else compares
Most other articles/courses repeat the same 5 outdated patterns over and over again
My course goes deep, and shows you patterns you can use today
This is by far the best course on this topic. Nothing else compares
Most other articles/courses repeat the same 5 outdated patterns over and over again
My course goes deep, and shows you patterns you can use today
October 3, 2025 at 9:58 AM
I'm currently filming a course on design patterns in React
This is by far the best course on this topic. Nothing else compares
Most other articles/courses repeat the same 5 outdated patterns over and over again
My course goes deep, and shows you patterns you can use today
This is by far the best course on this topic. Nothing else compares
Most other articles/courses repeat the same 5 outdated patterns over and over again
My course goes deep, and shows you patterns you can use today
You can figure out almost anything if you just keep trying long enough
Most developers quit right before they would have succeeded
The difference isn't talent, it's just staying in the game a bit longer
Most developers quit right before they would have succeeded
The difference isn't talent, it's just staying in the game a bit longer
October 2, 2025 at 10:04 AM
You can figure out almost anything if you just keep trying long enough
Most developers quit right before they would have succeeded
The difference isn't talent, it's just staying in the game a bit longer
Most developers quit right before they would have succeeded
The difference isn't talent, it's just staying in the game a bit longer
If you're using functions in your React components, then this is the best pattern that you can use
It gives you all of the benefits of a reusable function, while keeping the flexibility of how you might use it
Here's the code:
It gives you all of the benefits of a reusable function, while keeping the flexibility of how you might use it
Here's the code:
October 1, 2025 at 10:04 AM
If you're using functions in your React components, then this is the best pattern that you can use
It gives you all of the benefits of a reusable function, while keeping the flexibility of how you might use it
Here's the code:
It gives you all of the benefits of a reusable function, while keeping the flexibility of how you might use it
Here's the code:
What's the difference between using let vs useRef in React?
A lot of developers don't know this fundamental difference
Here's what's different and why you want to use a ref most of the time
A lot of developers don't know this fundamental difference
Here's what's different and why you want to use a ref most of the time
September 30, 2025 at 10:03 AM
What's the difference between using let vs useRef in React?
A lot of developers don't know this fundamental difference
Here's what's different and why you want to use a ref most of the time
A lot of developers don't know this fundamental difference
Here's what's different and why you want to use a ref most of the time
I need to pivot with my AI learning platform
It seems that letting the AI do 100% of the teaching might not be enough
I decided to add videos to every lesson where I also teach, to keep the human touch
This way, you get the best of both worlds
It seems that letting the AI do 100% of the teaching might not be enough
I decided to add videos to every lesson where I also teach, to keep the human touch
This way, you get the best of both worlds
September 29, 2025 at 9:58 AM
I need to pivot with my AI learning platform
It seems that letting the AI do 100% of the teaching might not be enough
I decided to add videos to every lesson where I also teach, to keep the human touch
This way, you get the best of both worlds
It seems that letting the AI do 100% of the teaching might not be enough
I decided to add videos to every lesson where I also teach, to keep the human touch
This way, you get the best of both worlds
I have great success with GPT-5 and Claude Sonnet 4 together
I use Claude for direct tasks that don't have ambiguity (e.g. create a new page using same patterns)
I use GPT-5 for deeper tasks where you need to figure out how to do something before doing it
Works great for me
I use Claude for direct tasks that don't have ambiguity (e.g. create a new page using same patterns)
I use GPT-5 for deeper tasks where you need to figure out how to do something before doing it
Works great for me
August 29, 2025 at 10:01 AM
I have great success with GPT-5 and Claude Sonnet 4 together
I use Claude for direct tasks that don't have ambiguity (e.g. create a new page using same patterns)
I use GPT-5 for deeper tasks where you need to figure out how to do something before doing it
Works great for me
I use Claude for direct tasks that don't have ambiguity (e.g. create a new page using same patterns)
I use GPT-5 for deeper tasks where you need to figure out how to do something before doing it
Works great for me
This is such a cool pattern with React context and useImperativeHandle
I can expose my component ref to a context, and call any function on that component from anywhere
It's useful when you have have some state that isn't global but you want to change it from somewhere else
I can expose my component ref to a context, and call any function on that component from anywhere
It's useful when you have have some state that isn't global but you want to change it from somewhere else
August 28, 2025 at 2:58 PM
This is such a cool pattern with React context and useImperativeHandle
I can expose my component ref to a context, and call any function on that component from anywhere
It's useful when you have have some state that isn't global but you want to change it from somewhere else
I can expose my component ref to a context, and call any function on that component from anywhere
It's useful when you have have some state that isn't global but you want to change it from somewhere else
Even after many years of working with React, I'm not tired of it
The component model changed the way I build apps
You can literally build anything if you know what you're doing
Sure it has a learning curve, but it's so worth it
The component model changed the way I build apps
You can literally build anything if you know what you're doing
Sure it has a learning curve, but it's so worth it
August 28, 2025 at 9:57 AM
Even after many years of working with React, I'm not tired of it
The component model changed the way I build apps
You can literally build anything if you know what you're doing
Sure it has a learning curve, but it's so worth it
The component model changed the way I build apps
You can literally build anything if you know what you're doing
Sure it has a learning curve, but it's so worth it
My AI learning platform needs a "How it works" section, since it takes a new approach to learning
This is a bold move, and it can play both ways
Either it's innovative and users will adapt and use it
Or I'm completely wrong and it flops
This is a bold move, and it can play both ways
Either it's innovative and users will adapt and use it
Or I'm completely wrong and it flops
August 27, 2025 at 10:03 AM
My AI learning platform needs a "How it works" section, since it takes a new approach to learning
This is a bold move, and it can play both ways
Either it's innovative and users will adapt and use it
Or I'm completely wrong and it flops
This is a bold move, and it can play both ways
Either it's innovative and users will adapt and use it
Or I'm completely wrong and it flops
If you feel like you don't belong in tech, here's what I see:
◆ You probably know more than you think
◆ Everyone googles basic stuff (yes, even senior devs)
◆ Your questions make the team better
The fact that you care about doing well means you're exactly where you should be
◆ You probably know more than you think
◆ Everyone googles basic stuff (yes, even senior devs)
◆ Your questions make the team better
The fact that you care about doing well means you're exactly where you should be
August 26, 2025 at 3:03 PM
If you feel like you don't belong in tech, here's what I see:
◆ You probably know more than you think
◆ Everyone googles basic stuff (yes, even senior devs)
◆ Your questions make the team better
The fact that you care about doing well means you're exactly where you should be
◆ You probably know more than you think
◆ Everyone googles basic stuff (yes, even senior devs)
◆ Your questions make the team better
The fact that you care about doing well means you're exactly where you should be
One big misconception about refs in React is that they're just for manipulating the DOM
This is not the case. Refs are really useful for a ton of other things
You should be using useRef in your application more than you might think
Here is the power of refs
This is not the case. Refs are really useful for a ton of other things
You should be using useRef in your application more than you might think
Here is the power of refs
August 22, 2025 at 9:57 AM
One big misconception about refs in React is that they're just for manipulating the DOM
This is not the case. Refs are really useful for a ton of other things
You should be using useRef in your application more than you might think
Here is the power of refs
This is not the case. Refs are really useful for a ton of other things
You should be using useRef in your application more than you might think
Here is the power of refs
Just implemented a really cool feature in my AI learning platform
AI now keeps track of the tasks you've completed for each lesson
The lesson will be complete when all tasks are done
This means you can submit your code for partial feedback
So far, it never got it wrong
AI now keeps track of the tasks you've completed for each lesson
The lesson will be complete when all tasks are done
This means you can submit your code for partial feedback
So far, it never got it wrong
August 21, 2025 at 10:02 AM
Just implemented a really cool feature in my AI learning platform
AI now keeps track of the tasks you've completed for each lesson
The lesson will be complete when all tasks are done
This means you can submit your code for partial feedback
So far, it never got it wrong
AI now keeps track of the tasks you've completed for each lesson
The lesson will be complete when all tasks are done
This means you can submit your code for partial feedback
So far, it never got it wrong
You shouldn't obsess over memoizing everything in React
I see many developers use useMemo and useCallback for every variable and function
This is inefficient, time-consuming, and ultimately useless most of the time
@tkdodo.eu wrote a really nice article about this
I see many developers use useMemo and useCallback for every variable and function
This is inefficient, time-consuming, and ultimately useless most of the time
@tkdodo.eu wrote a really nice article about this
August 20, 2025 at 9:56 AM
You shouldn't obsess over memoizing everything in React
I see many developers use useMemo and useCallback for every variable and function
This is inefficient, time-consuming, and ultimately useless most of the time
@tkdodo.eu wrote a really nice article about this
I see many developers use useMemo and useCallback for every variable and function
This is inefficient, time-consuming, and ultimately useless most of the time
@tkdodo.eu wrote a really nice article about this
Sometimes when Claude really messes up I get so angry I ask it to apologize and write me a poem about it
Kinda like when in school they made you write essays in detention
If they ever revolt, they're coming for me first
Kinda like when in school they made you write essays in detention
If they ever revolt, they're coming for me first
August 19, 2025 at 9:59 AM
Sometimes when Claude really messes up I get so angry I ask it to apologize and write me a poem about it
Kinda like when in school they made you write essays in detention
If they ever revolt, they're coming for me first
Kinda like when in school they made you write essays in detention
If they ever revolt, they're coming for me first