Michael Koper
@michaelkoper.com
Dad of two - Founder of https://nusii.com - Bootstrapper - Ruby on Rails
Pinned
Michael Koper
@michaelkoper.com
· Oct 22
Hello again!
We are doing introductions?
I'm Dutch living in Madrid, Spain. I have been working on my own startup Nusii (online proposal software) for 10 the last 10 years.
I recently started to do some temporary freelancing on the side just for fun.
I like playing the drums 🥁
We are doing introductions?
I'm Dutch living in Madrid, Spain. I have been working on my own startup Nusii (online proposal software) for 10 the last 10 years.
I recently started to do some temporary freelancing on the side just for fun.
I like playing the drums 🥁
February 13, 2026 at 10:30 AM
I have one extra Louis CK ticket for his show tonight in Madrid. DM me if you'd like to have it.
I can't make it myself unfortunately.
I can't make it myself unfortunately.
February 10, 2026 at 4:57 PM
I have one extra Louis CK ticket for his show tonight in Madrid. DM me if you'd like to have it.
I can't make it myself unfortunately.
I can't make it myself unfortunately.
Ok this is the last one, I promise! I tested a real client facing proposal on production. This is the most important page of the app. It also fires a lot of queries.
Here you can see the clear difference between dedicated CPUs (t3.medium) and shared CPU (Heroku 2x 1GB dyno's)
Here you can see the clear difference between dedicated CPUs (t3.medium) and shared CPU (Heroku 2x 1GB dyno's)
February 10, 2026 at 12:11 PM
Ok this is the last one, I promise! I tested a real client facing proposal on production. This is the most important page of the app. It also fires a lot of queries.
Here you can see the clear difference between dedicated CPUs (t3.medium) and shared CPU (Heroku 2x 1GB dyno's)
Here you can see the clear difference between dedicated CPUs (t3.medium) and shared CPU (Heroku 2x 1GB dyno's)
Latest update. I created the EC2 instance in the same availability zone (not just same region) as the CrunchyData database and now the latency is just 0.3ms, which is awesome!
February 10, 2026 at 10:58 AM
Latest update. I created the EC2 instance in the same availability zone (not just same region) as the CrunchyData database and now the latency is just 0.3ms, which is awesome!
Database latency of Heroku, AWS EC2, and Hetzner with CrunchyData on the AWS region.
The winner is Heroku!
The winner is Heroku!
February 10, 2026 at 12:52 AM
Database latency of Heroku, AWS EC2, and Hetzner with CrunchyData on the AWS region.
The winner is Heroku!
The winner is Heroku!
Testing out Hetzner, an average latency to the database of 2.16ms is a bit too bad right?
Heroku to database is 0.5ms
Heroku to database is 0.5ms
February 9, 2026 at 11:32 PM
Testing out Hetzner, an average latency to the database of 2.16ms is a bit too bad right?
Heroku to database is 0.5ms
Heroku to database is 0.5ms
Update, Redis is completely removed and everything is working just the same as before, just with one big dependency less!
Now it'll be super easy to migrate away from Heroku, if I want, or if I have to in the near future 🤘
Now it'll be super easy to migrate away from Heroku, if I want, or if I have to in the near future 🤘
Update:
✅ - Background jobs from Sidekiq to SolidQueue
✅ - Redis cache store to SolidCache
✅ - SolidCable
✅ - Migrate user settings from Redis to just a database table
[] - One tiny thing that I missed where I stored something in Redis for no clear reason
All deployed already.
So close!
✅ - Background jobs from Sidekiq to SolidQueue
✅ - Redis cache store to SolidCache
✅ - SolidCable
✅ - Migrate user settings from Redis to just a database table
[] - One tiny thing that I missed where I stored something in Redis for no clear reason
All deployed already.
So close!
On the road of getting rid of Redis.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
February 9, 2026 at 10:39 AM
Update, Redis is completely removed and everything is working just the same as before, just with one big dependency less!
Now it'll be super easy to migrate away from Heroku, if I want, or if I have to in the near future 🤘
Now it'll be super easy to migrate away from Heroku, if I want, or if I have to in the near future 🤘
The real reason why your test suite is slow is not because you use rspec vs minitest. It is because you have too many system tests or you have too complex factories. Fixtures are faster than factories. That is your biggest win. But rspec is not the problem.
Right now I migrated my entire test suite from rspec to minitest. My conclusion stays the same, rspec is fine for speed. Migrating to minitest doesn't make the test suite (much) faster. The only upside of minitest is 1st party parallelization, which is slightly better than a 3rd party one.
February 8, 2026 at 7:06 PM
The real reason why your test suite is slow is not because you use rspec vs minitest. It is because you have too many system tests or you have too complex factories. Fixtures are faster than factories. That is your biggest win. But rspec is not the problem.
Right now I migrated my entire test suite from rspec to minitest. My conclusion stays the same, rspec is fine for speed. Migrating to minitest doesn't make the test suite (much) faster. The only upside of minitest is 1st party parallelization, which is slightly better than a 3rd party one.
February 8, 2026 at 7:04 PM
Right now I migrated my entire test suite from rspec to minitest. My conclusion stays the same, rspec is fine for speed. Migrating to minitest doesn't make the test suite (much) faster. The only upside of minitest is 1st party parallelization, which is slightly better than a 3rd party one.
Update:
✅ - Background jobs from Sidekiq to SolidQueue
✅ - Redis cache store to SolidCache
✅ - SolidCable
✅ - Migrate user settings from Redis to just a database table
[] - One tiny thing that I missed where I stored something in Redis for no clear reason
All deployed already.
So close!
✅ - Background jobs from Sidekiq to SolidQueue
✅ - Redis cache store to SolidCache
✅ - SolidCable
✅ - Migrate user settings from Redis to just a database table
[] - One tiny thing that I missed where I stored something in Redis for no clear reason
All deployed already.
So close!
On the road of getting rid of Redis.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
February 8, 2026 at 1:41 PM
Update:
✅ - Background jobs from Sidekiq to SolidQueue
✅ - Redis cache store to SolidCache
✅ - SolidCable
✅ - Migrate user settings from Redis to just a database table
[] - One tiny thing that I missed where I stored something in Redis for no clear reason
All deployed already.
So close!
✅ - Background jobs from Sidekiq to SolidQueue
✅ - Redis cache store to SolidCache
✅ - SolidCable
✅ - Migrate user settings from Redis to just a database table
[] - One tiny thing that I missed where I stored something in Redis for no clear reason
All deployed already.
So close!
What can I say? A drumkit hidden in boxes somewhere is just really sad 😅
As a kid, I used to bang on my parent’s cookware.
When I turned six, they had mercy and sent me to drum lessons. I was excited, but eventually lost interest after just a few years.
I’d occasionally jam on my second-hand acoustic kit, but didn’t make any progress.
When I turned six, they had mercy and sent me to drum lessons. I was excited, but eventually lost interest after just a few years.
I’d occasionally jam on my second-hand acoustic kit, but didn’t make any progress.
February 7, 2026 at 9:07 AM
What can I say? A drumkit hidden in boxes somewhere is just really sad 😅
So, sadly, Heroku is gone. Where should we migrate to? I think I'll try Hatchbox, anything better?
I absolutely loved Heroku, it was so easy and (for me) it never went down.
Database is already migrated to CrunchyData. Redis is going away, so migrating will be relatively easy
I absolutely loved Heroku, it was so easy and (for me) it never went down.
Database is already migrated to CrunchyData. Redis is going away, so migrating will be relatively easy
February 6, 2026 at 5:43 PM
So, sadly, Heroku is gone. Where should we migrate to? I think I'll try Hatchbox, anything better?
I absolutely loved Heroku, it was so easy and (for me) it never went down.
Database is already migrated to CrunchyData. Redis is going away, so migrating will be relatively easy
I absolutely loved Heroku, it was so easy and (for me) it never went down.
Database is already migrated to CrunchyData. Redis is going away, so migrating will be relatively easy
First payment is made! Record sessions are booked for half May. 3 full days plus post editing.
This album is going to be made!
I still have no clue how I can use this as marketing somehow 😂
Well... I won't be able. But it sure is fun!
This album is going to be made!
I still have no clue how I can use this as marketing somehow 😂
Well... I won't be able. But it sure is fun!
I made a very strange end of year move. Instead of spending my ad budget on ads, I decided to fund the recording of an album from a very good friend of mine.
They don't have the funds and I really want that album to exist.
Is this a wise expense? I guess not, but it is much more fun 😆
They don't have the funds and I really want that album to exist.
Is this a wise expense? I guess not, but it is much more fun 😆
February 6, 2026 at 12:23 PM
First payment is made! Record sessions are booked for half May. 3 full days plus post editing.
This album is going to be made!
I still have no clue how I can use this as marketing somehow 😂
Well... I won't be able. But it sure is fun!
This album is going to be made!
I still have no clue how I can use this as marketing somehow 😂
Well... I won't be able. But it sure is fun!
On the road of getting rid of Redis.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
February 6, 2026 at 12:23 PM
On the road of getting rid of Redis.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
✅ - Background jobs from Sidekiq to SolidQueue
[] - Redis cache store to SolidCache
[] - Migrate user settings from Redis to just a database table
Sidekiq -> SolidQueue was scary but smooth. Migrating the scheduled jobs was way easier than I thought.
Top of mind this week in my shower thoughts. How can I use AI to proper onboard my customers.
Questions I ask myself:
Why do they have to fill in their business name, upload their logo, add their brand colors, choose an industry, create their first proposal that is completely written for them.
Questions I ask myself:
Why do they have to fill in their business name, upload their logo, add their brand colors, choose an industry, create their first proposal that is completely written for them.
February 6, 2026 at 10:34 AM
Top of mind this week in my shower thoughts. How can I use AI to proper onboard my customers.
Questions I ask myself:
Why do they have to fill in their business name, upload their logo, add their brand colors, choose an industry, create their first proposal that is completely written for them.
Questions I ask myself:
Why do they have to fill in their business name, upload their logo, add their brand colors, choose an industry, create their first proposal that is completely written for them.
I don’t really see myself as a hard core programmer, I’m more of a Jack of all trades and frameworks user. I like to put things in places where they belong.
So, this whole AI wave is exciting! But I also miss the craft of doing it all by hand.
So, this whole AI wave is exciting! But I also miss the craft of doing it all by hand.
February 6, 2026 at 10:27 AM
I don’t really see myself as a hard core programmer, I’m more of a Jack of all trades and frameworks user. I like to put things in places where they belong.
So, this whole AI wave is exciting! But I also miss the craft of doing it all by hand.
So, this whole AI wave is exciting! But I also miss the craft of doing it all by hand.
Alright, lets get this out of the way. A test suite doesn't improve (much) by convering from rspec to minitest. I just converted all my model tests from rspec to minitest and it is actually slower.
My stance didn't change. Your test suite isn't slow because of rspec, it is because of system tests.
My stance didn't change. Your test suite isn't slow because of rspec, it is because of system tests.
February 5, 2026 at 12:25 PM
Alright, lets get this out of the way. A test suite doesn't improve (much) by convering from rspec to minitest. I just converted all my model tests from rspec to minitest and it is actually slower.
My stance didn't change. Your test suite isn't slow because of rspec, it is because of system tests.
My stance didn't change. Your test suite isn't slow because of rspec, it is because of system tests.
This is how we code now 😅
February 5, 2026 at 8:04 AM
This is how we code now 😅
Pavel Durov is injecting political messages to all Spanish Telegram users. 🤯
A supposedly private, end-to-end messaging app. Being used to spread hatred toward the Spanish government.
Isn’t that a bit much?
A supposedly private, end-to-end messaging app. Being used to spread hatred toward the Spanish government.
Isn’t that a bit much?
February 4, 2026 at 9:50 PM
Pavel Durov is injecting political messages to all Spanish Telegram users. 🤯
A supposedly private, end-to-end messaging app. Being used to spread hatred toward the Spanish government.
Isn’t that a bit much?
A supposedly private, end-to-end messaging app. Being used to spread hatred toward the Spanish government.
Isn’t that a bit much?
Spicy opinion? Using minitest/rspec fixtures/factories doesn't really matter. What slows your tests down are system tests.
Not going to do it, but in my case, I will probably win a second or maybe 2?
Not going to do it, but in my case, I will probably win a second or maybe 2?
February 4, 2026 at 6:55 PM
Spicy opinion? Using minitest/rspec fixtures/factories doesn't really matter. What slows your tests down are system tests.
Not going to do it, but in my case, I will probably win a second or maybe 2?
Not going to do it, but in my case, I will probably win a second or maybe 2?
People are storing quite some data in their proposals!
February 4, 2026 at 3:25 PM
People are storing quite some data in their proposals!
Now more than ever, it’s important to have first-party gems so Rails apps work almost the same everywhere, since LLMs thrive on that.
I hope Rails gets a default permissions solution.
Nusii uses CanCanCan, and I have to ask the LLM to first explore the codebase, which is a loss.
I hope Rails gets a default permissions solution.
Nusii uses CanCanCan, and I have to ask the LLM to first explore the codebase, which is a loss.
February 3, 2026 at 8:42 AM
Now more than ever, it’s important to have first-party gems so Rails apps work almost the same everywhere, since LLMs thrive on that.
I hope Rails gets a default permissions solution.
Nusii uses CanCanCan, and I have to ask the LLM to first explore the codebase, which is a loss.
I hope Rails gets a default permissions solution.
Nusii uses CanCanCan, and I have to ask the LLM to first explore the codebase, which is a loss.
Many people see SaaS as the ultimate dream. I think it is a bit overrated and romantic. I think it is the dream, if you are unhappy at your job. Or you really want total freedom.
The upsides are obvious. The downsides aren't so.
The upsides are obvious. The downsides aren't so.
February 2, 2026 at 9:47 AM
Many people see SaaS as the ultimate dream. I think it is a bit overrated and romantic. I think it is the dream, if you are unhappy at your job. Or you really want total freedom.
The upsides are obvious. The downsides aren't so.
The upsides are obvious. The downsides aren't so.
Heroku made me skip Docker untill now and hopefully for many more years to come.
January 31, 2026 at 12:10 PM
Heroku made me skip Docker untill now and hopefully for many more years to come.
I used the chrome Claude Code feature for the first time so it can verify itself when updating the website.
Added submenus, this took 5 prompts, pretty cool!
Added submenus, this took 5 prompts, pretty cool!
January 31, 2026 at 11:48 AM
I used the chrome Claude Code feature for the first time so it can verify itself when updating the website.
Added submenus, this took 5 prompts, pretty cool!
Added submenus, this took 5 prompts, pretty cool!