Lucas Fernandes
@vulgofoobar.bsky.social
Hello there! My name is Lucas, from São Paulo - Brazil, and I'm a Software Engineer with over 5 years of experience specializing in Ruby on Rails and SaaS products.
TIL: how does rails request interact w db?
1 request = n queries = n objects per query = borrows one connection from shared pool
#ruby #performance #devlife
1 request = n queries = n objects per query = borrows one connection from shared pool
#ruby #performance #devlife
September 1, 2026 at 9:31 PM
TIL: how does rails request interact w db?
1 request = n queries = n objects per query = borrows one connection from shared pool
#ruby #performance #devlife
1 request = n queries = n objects per query = borrows one connection from shared pool
#ruby #performance #devlife
TIL: why N+1 is bad
every query pays network latency (worse across regions); CPU/IO spikes = rails framework overhead + db parse/plan/execute per query; db connection is expensive and hold it is bad for concurrent envs
we really want to talk little to db!
#performance #ruby #devlife
every query pays network latency (worse across regions); CPU/IO spikes = rails framework overhead + db parse/plan/execute per query; db connection is expensive and hold it is bad for concurrent envs
we really want to talk little to db!
#performance #ruby #devlife
August 31, 2026 at 7:58 PM
TIL: why N+1 is bad
every query pays network latency (worse across regions); CPU/IO spikes = rails framework overhead + db parse/plan/execute per query; db connection is expensive and hold it is bad for concurrent envs
we really want to talk little to db!
#performance #ruby #devlife
every query pays network latency (worse across regions); CPU/IO spikes = rails framework overhead + db parse/plan/execute per query; db connection is expensive and hold it is bad for concurrent envs
we really want to talk little to db!
#performance #ruby #devlife
TIL: what's eager loading?
technique to load associations; in advance in the same query; into RAM
#devlife #performance #ruby
technique to load associations; in advance in the same query; into RAM
#devlife #performance #ruby
August 3, 2026 at 10:38 PM
TIL: what's eager loading?
technique to load associations; in advance in the same query; into RAM
#devlife #performance #ruby
technique to load associations; in advance in the same query; into RAM
#devlife #performance #ruby
TIL: what is n+1 query?
when collection access associations; additional query for each collection item; like sql being called inside a loop; we want to talk little to database as possible
#devlife #performance
when collection access associations; additional query for each collection item; like sql being called inside a loop; we want to talk little to database as possible
#devlife #performance
July 30, 2026 at 10:39 PM
TIL: what is n+1 query?
when collection access associations; additional query for each collection item; like sql being called inside a loop; we want to talk little to database as possible
#devlife #performance
when collection access associations; additional query for each collection item; like sql being called inside a loop; we want to talk little to database as possible
#devlife #performance
TIL: what are the pros n cons of open source ai?
pros: full control (privacy/run anywhere), cheaper, customizable, no vendor lock-in, auditable n innovation multiplier;
cons: complex setup, hardware intensive, fewer out of the box capabilities n you manage security, scale and uptime
#ai #devlife
pros: full control (privacy/run anywhere), cheaper, customizable, no vendor lock-in, auditable n innovation multiplier;
cons: complex setup, hardware intensive, fewer out of the box capabilities n you manage security, scale and uptime
#ai #devlife
July 28, 2026 at 8:43 PM
July 16, 2026 at 9:05 PM
Neal.fun
Games, visualizations, interactives and other weird stuff.
neal.fun
July 8, 2026 at 7:56 PM
how to approach programming in a fun way?
use tools and knowledge to deliver an end product; impact someone's life and enjoy the ride! ✨
#devlife
use tools and knowledge to deliver an end product; impact someone's life and enjoy the ride! ✨
#devlife
July 7, 2026 at 11:47 PM
how to approach programming in a fun way?
use tools and knowledge to deliver an end product; impact someone's life and enjoy the ride! ✨
#devlife
use tools and knowledge to deliver an end product; impact someone's life and enjoy the ride! ✨
#devlife
I came up with this minimal theme for my new macOS menu bar that looks just like my Obsidian theme. 🤓
#sketchybar #macos #ui #customization
#sketchybar #macos #ui #customization
June 23, 2026 at 1:59 PM
I came up with this minimal theme for my new macOS menu bar that looks just like my Obsidian theme. 🤓
#sketchybar #macos #ui #customization
#sketchybar #macos #ui #customization
this post resonates with me a lot. we don't know each other, but I hope you all the best on your next move @stefannibrasil.me ! ✨
www.stefannibrasil.me/posts/notes/...
www.stefannibrasil.me/posts/notes/...
The Joy of Doing Hard Things
I should have known better than comparing myself to others by now, but we all need our moments of starring into the abyss and finding our way through: being afraid to change is not how I want to live ...
www.stefannibrasil.me
May 27, 2026 at 5:36 PM
this post resonates with me a lot. we don't know each other, but I hope you all the best on your next move @stefannibrasil.me ! ✨
www.stefannibrasil.me/posts/notes/...
www.stefannibrasil.me/posts/notes/...
TIL: what's the ai scaling laws?
more computation power + more trained data = more performance + new abilities
these explain a lot these days...
#ai #devlife #softwareengineering
more computation power + more trained data = more performance + new abilities
these explain a lot these days...
#ai #devlife #softwareengineering
May 21, 2026 at 6:34 PM
TIL: what's the ai scaling laws?
more computation power + more trained data = more performance + new abilities
these explain a lot these days...
#ai #devlife #softwareengineering
more computation power + more trained data = more performance + new abilities
these explain a lot these days...
#ai #devlife #softwareengineering
TIL: why do llms hallucinate?
llms are trained to predict text; they don't check facts against the training data and have no knowledge; training data has gaps, inconsistencies, and underrepresented topics.
there is no intelligence in artificial intelligence 🙃
#ai #devlife #softwareengineering
llms are trained to predict text; they don't check facts against the training data and have no knowledge; training data has gaps, inconsistencies, and underrepresented topics.
there is no intelligence in artificial intelligence 🙃
#ai #devlife #softwareengineering
May 21, 2026 at 12:39 AM
TIL: why do llms hallucinate?
llms are trained to predict text; they don't check facts against the training data and have no knowledge; training data has gaps, inconsistencies, and underrepresented topics.
there is no intelligence in artificial intelligence 🙃
#ai #devlife #softwareengineering
llms are trained to predict text; they don't check facts against the training data and have no knowledge; training data has gaps, inconsistencies, and underrepresented topics.
there is no intelligence in artificial intelligence 🙃
#ai #devlife #softwareengineering
TIL: what are ai's capabilities and limitations?
capabilities: conversational awareness, context switching without retraining and external tool integration. limitations are: hallucination potential, knowledge cutoff dates, complex reasoning challenges and context window constraints
#ai #devlife
capabilities: conversational awareness, context switching without retraining and external tool integration. limitations are: hallucination potential, knowledge cutoff dates, complex reasoning challenges and context window constraints
#ai #devlife
May 18, 2026 at 7:41 PM
I got my Ruby passport! ✨ it was nice talking to some of you at #tropicalonrails. thank you for conversations!
April 13, 2026 at 8:24 PM
I got my Ruby passport! ✨ it was nice talking to some of you at #tropicalonrails. thank you for conversations!
I just got a ticket for tropical on rails! ✨ lesgooo! who am I gonna see there?
#tropicalonrails #rubyonrails
#tropicalonrails #rubyonrails
April 7, 2026 at 6:32 PM
I just got a ticket for tropical on rails! ✨ lesgooo! who am I gonna see there?
#tropicalonrails #rubyonrails
#tropicalonrails #rubyonrails
TIL: should I use single or double quotes in git commit messages?
both works fine, but go for the single; double quotes might trigger "command substitution" on unix-like systems
for example:
```bash
echo "`ls`"
./docs/
./node_modules/
./package-lock.json
./package.json
./pages/
```
#git #devlife
both works fine, but go for the single; double quotes might trigger "command substitution" on unix-like systems
for example:
```bash
echo "`ls`"
./docs/
./node_modules/
./package-lock.json
./package.json
./pages/
```
#git #devlife
March 6, 2026 at 9:45 PM
I've been playing around with the `gum` gem from the `charm-ruby` ecosystem to glam up my scripts and aliases. I wrote a script that makes your scripts available from anywhere on your system.
#ruby #gum #charmruby #devlife #nasa
#ruby #gum #charmruby #devlife #nasa
February 27, 2026 at 2:36 PM
I've been playing around with the `gum` gem from the `charm-ruby` ecosystem to glam up my scripts and aliases. I wrote a script that makes your scripts available from anywhere on your system.
#ruby #gum #charmruby #devlife #nasa
#ruby #gum #charmruby #devlife #nasa
what are the exciting features in ruby 4 release?
experimental `Ruby::Box` isolation mechanism; new zjit compiler; performance improvements for class instantiation; `Set` and `Path` classes promoted to core classes
#ruby #devlife #softwareengineer
experimental `Ruby::Box` isolation mechanism; new zjit compiler; performance improvements for class instantiation; `Set` and `Path` classes promoted to core classes
#ruby #devlife #softwareengineer
February 26, 2026 at 6:42 PM
what are the exciting features in ruby 4 release?
experimental `Ruby::Box` isolation mechanism; new zjit compiler; performance improvements for class instantiation; `Set` and `Path` classes promoted to core classes
#ruby #devlife #softwareengineer
experimental `Ruby::Box` isolation mechanism; new zjit compiler; performance improvements for class instantiation; `Set` and `Path` classes promoted to core classes
#ruby #devlife #softwareengineer
TIL: what's git commit amend? does it modify the previous commit?
it's like a time travel; rewrites the repo timeline; amend staged files to "previous" commit; previous commit is actually replaced and not modified; commits are immutable
#git #softwareengineer #learninginpublic #devlife
it's like a time travel; rewrites the repo timeline; amend staged files to "previous" commit; previous commit is actually replaced and not modified; commits are immutable
#git #softwareengineer #learninginpublic #devlife
February 19, 2026 at 2:11 PM
TIL: what's git commit amend? does it modify the previous commit?
it's like a time travel; rewrites the repo timeline; amend staged files to "previous" commit; previous commit is actually replaced and not modified; commits are immutable
#git #softwareengineer #learninginpublic #devlife
it's like a time travel; rewrites the repo timeline; amend staged files to "previous" commit; previous commit is actually replaced and not modified; commits are immutable
#git #softwareengineer #learninginpublic #devlife
does privacy matter to you? do you want to be in control of your services?
in this post, I’ll show you how to self-host your apps with minimal effort. the possibilities are endless! ✨
check it out: jaggies-weekly.netlify.app/how-to-self-...
#devlife #learninpublic #selfhosting #linux #umbrel
in this post, I’ll show you how to self-host your apps with minimal effort. the possibilities are endless! ✨
check it out: jaggies-weekly.netlify.app/how-to-self-...
#devlife #learninpublic #selfhosting #linux #umbrel
How to self-host your apps locally | Jaggies Weekly
TLDR 1. Prepare a bootable USB with the umbrelOS .iso and Balena Etcher
2. Boot your server device from USB
3. Install umbrelOS and remove…
jaggies-weekly.netlify.app
January 8, 2026 at 8:03 PM
does privacy matter to you? do you want to be in control of your services?
in this post, I’ll show you how to self-host your apps with minimal effort. the possibilities are endless! ✨
check it out: jaggies-weekly.netlify.app/how-to-self-...
#devlife #learninpublic #selfhosting #linux #umbrel
in this post, I’ll show you how to self-host your apps with minimal effort. the possibilities are endless! ✨
check it out: jaggies-weekly.netlify.app/how-to-self-...
#devlife #learninpublic #selfhosting #linux #umbrel
recently, I've been amazed by the UK jungle culture and what makes something jungle. I'm excited to share my first jungle track and actually, my first track ever! ✨
Check it out at: vulgovarios.bandcamp.com/album/modern...
#jungle #cooking #music
Check it out at: vulgovarios.bandcamp.com/album/modern...
#jungle #cooking #music
modern jungle, by varios
2 track album
vulgovarios.bandcamp.com
December 24, 2025 at 1:11 PM
recently, I've been amazed by the UK jungle culture and what makes something jungle. I'm excited to share my first jungle track and actually, my first track ever! ✨
Check it out at: vulgovarios.bandcamp.com/album/modern...
#jungle #cooking #music
Check it out at: vulgovarios.bandcamp.com/album/modern...
#jungle #cooking #music