Edwin Cruz

Principal Engineer at @weareMagmaLabs, father, husband, Malinois trainer apprentice, and of course Rubyist! Need help with your Ruby Project? Contact me

[América Rangel @AmerangelLorenz]

Seré breve:

Necesitamos un presidente que defienda a TUS hijos, no a los hijos de AMLO.

Fin.

[Manuel Lopez San Martin @MLopezSanMartin]

"Ya cuando se descarrile será otro pedo”

Y se descarriló…

Así decía Pedro Salazar Beltran (primo de Andy, José Ramón y Gonzalo, hijos de AMLO) a Amilcar Olan sobre la venta de balastro de mala calidad

Hoy 13 personas murieron por descarrilamiento del Tren Interoceánico

[Kevin Weil 🇺🇸 @kevinweil]

High school student uses AI to discover 1M+ objects humans missed in astronomical data. Head of NASA openly recruiting him through Twitter with a fighter jet ride included.

All my worlds colliding. I love everything about this.

[Mario Nawfal @MarioNawfal]

🇸🇻 OPINION: EL SALVADOR GAVE EVERY STUDENT A TEACHER THAT NEVER SLEEPS

Last week in a coastal classroom, a student reportedly asked how Bitcoin actually works.
Grok didn’t just explain it.

it guided the student through a simulated transaction, step by step, before the bell rang.

In the mountains, another kid wanted to design earthquake proof homes.

Grok pulled fifty years of seismic data, showed how buildings sway under stress, and helped build a 3D model that could survive the quakes that once flattened their town.

In a crowded city school with one textbook for forty students, a teacher asked Grok to rewrite a history lesson for different reading levels.

Forty-five seconds later, seven custom versions arrived, each with questions that adapt to how fast each student learns.

Since Grok rolled out nationwide, the results are already stunning.

Grade 5 math scores have jumped 21% in just eight weeks.
Reading proficiency has climbed from 34% to 59%.

Nearly half of students now stay after school voluntarily, just to keep learning with their pocket tutor.

Every child in El Salvador now has a personal, tireless, infinitely patient teacher, free, 24/7, and in their native language thanks to @nayibbukele.

While the rest of the world still debates “AI in education” in endless policy meetings, El Salvador quietly turned its schools into the smartest classrooms on Earth.

No limits, just learning that never sleeps.

Sources: Forbes, Coindesk, BBC @XFreeze

[Claudia Sheinbaum Pardo @Claudiashein]

¿Por qué toda la fuerza del estado contra los estudiantes y no contra los narcos? son narco-estado @diazpol @jenarovillamil

[Nidhi Sarvaiya @sarvaiya_nidhi]

🚀 Keep your Rails app dependencies up-to-date with a simple command:

💎 bundle outdated
✔️ Lists outdated gems without making changes
✔️ Lets you focus on safe, selective updates
✔️ Reduces risk of breaking changes

Stay ahead of tech debt!

#RubyOnRails #RailsTips

[Chambeología @chambeologia]

Como episodio #036, te dejo con Edwin Cruz, uno de los developers más Ingeniero de la zona hidrocálida. Que disfrutes su genuina historia 🎙️ @softr8

https://t.co/vIfJ186I1i

[Obie Fernandez @obie]

Announcing The Rails 8 Way available today along with the latest version of Ruby on Rails just announced by @dhh at #railsworld2024

https://t.co/adZmbteT1A

#nopaas
#nobuild
#rubyonrails
#railsworld

[Adam Wolff @dmwlff]

I ended my time at @Meta as a director.

But I started as an engineer on FB Chat.

Everything about it was broken — we had to rewrite it.

And while the effort to fix it is one the projects that led to @reactjs, the most important fix was far simpler...

Here’s the full story:

—

I worked on Facebook Chat for several years, both on the front end and the infrastructure.

Before the major effort to redo the UI, FB Chat was super broken and we had no idea why.

We got tons of bug reports about Chat being broken every day, but we noticed an odd pattern in the data: the volume of reports didn’t match the volume of usage. It was time-shifted from the peaks we’d see in the US.

We didn’t know what was wrong, but we knew the code was a mess.

We set about rewriting both the front-end and the back-end in an effort to fix it.

The front-end rewrite pulled in a whole team of amazing engineers and became one of the big threads that led to @reactjs

In the public eye, we portrayed this project as the one that ultimately fixed Chat.

And the way I’ve usually told it, fixing Facebook Chat and the birth of React are the same story.

But no framework was going to fix the worst problem with Chat.

—

During the time we were working on the Chat rewrite, we were also replacing the original Erlang backend with one written in C++.

This was probably a good move, but the problem wasn’t with Erlang either.

Our initial spec for the new backend didn’t say much about observability, but it was an important feature, and the rewrite forced us to rebuild it.

Little did we know this would lead us to the root cause of our problems…

When we finally gained insight into our deliverability data, we were able to cut it by region.

We noticed Chat was really popular in India. This was before WhatsApp, at a time when SMS wasn’t reliable.

Eventually we pinpointed a region in India where one specific DNS provider was giving out the wrong IP addresses for our Chat servers.

So when people went to use Chat, they would sometimes get a notification that they had a message, and then it would disappear.

Or they’d send a message and it would get lost. All because they were connecting to the wrong IP address.

That was it!

None of the sexy new tech we were working on was going to solve that problem.

Ever.

—

Instead, the solution was to build observability that allowed us to track end-to-end message delivery.

In the end, we could start with a broad cut of our data by country or web browser, and then zoom all the way in to look at what happened to a specific message for a specific user.

Once we pinpointed that the problem was with a DNS server, the matter was resolved with a quick phone call. I don’t know what they did, but I imagine it was something like turning it off and turning it on again.

We sometimes talk about observability as if it’s enough to buy a product like Datadog and just look at the pretty graphs.

Sure, that’s a start.

But true observability is a feature that needs to be built— painstakingly, iteratively, by-definition starting with a shot in the dark.

—

These days, it has become fashionable to poo-poo the idea of being data-driven.

People point out that measurement can distort the phenomenon that is being observed.

They want to make processes “data-informed.”

But this seems like silly backlash against the only rigorous standard in all of software engineering:

That we hold ourselves to an objective standard.

We measure how long things take, how many errors we encounter, how often a process successfully runs to completion.

So here’s what this experience taught me about observability:

When an issue happens in production, time-box the investigation.

Sure, take a few hours to try and figure it out by looking in the logs and inspecting the code.

But if you’re coming to the end of the day and you still don’t have a fix, then push a PR that adds logging.

The first one may be just a guess, but it will begin a process that leads to the truth.

And that is what we should all ultimately be striving for.
—
For more engineering tips and stories, follow me @dmwlff

[MrBeast @MrBeast]

I’m gonna give 10 random people that repost this and follow me $25,000 for fun (the $250,000 my X video made)

I’ll pick the winners in 72 hours

[Paweł Dąbrowski @pdabrowski6]

#Ruby is not dead ❤️ and it powered the ticketing and seat management system for Golden Globes this year 🚀 I had a pleasure to architect and deliver the code at @iRonin_IT

[DHH @dhh]

New rate limiting API coming to Rails 8, courtesy of Kredis' new limiter type. Just in time for the upcoming authentication generator to need protection from brute-force attacks! https://t.co/UOxa40Nq2I

[Edwin Cruz @softr8]

This is my #GitHubUnwrapped! Get your own: https://t.co/K3Z10aXw0M

[Aarón Benítez @aaronbenitez_]

Gastos hormiga: no son importantes. No construyes riqueza enfocándote en cuidar esto. Lo siento, alguien te lo tiene que decir. Me explico: el ancho de banda mental que tú y yo tenemos para poner atención a los asuntos del mundo es bastante limitado. Usar parte de esto cuidando los gastos hormigas simplemente nos hace sentir que estamos haciendo bien las cosas, que estamos siendo buenos con nuestras finanzas y demás, nos da un cierto grado de tranquilidad emocional porque estamos controlando algo que luce como importante. Mira, hacer cálculos sencillos de la gran cantidad de dinero que ahorras al año si dejas de pagar Netflix, Spotify y demás es el enfoque incorrecto. Te voy a decir cuál es mi pleito contra los gastos hormiga: lo que generan en ti es una mentalidad hormiga. No creas riqueza preocupado por cuestiones pequeñas, te lo juro que no, aunque los expertos financieros de bolsillo te quieren vender esto como la gran solución. Tu mente no puede dominar ser genial en cositas pequeñas y en asuntos de alto impacto al mismo tiempo, tienes que elegir ser experto en una de estas opciones. De nuevo, aunque cuidar los gastos hormiga suena bien, lo que más generan en ti es una mentalidad hormiga donde desarrollas el hábito de estar alerta a las cosas pequeñas en lugar de ser capaz de detectar grandes oportunidades y meterte a ellas con TADI. Va con amor, para iniciar una semana donde empujes las cosas que sí importan.

[Yaroslav Shmarov @yarotheslav]

Here is how you can use good_job and skip adding Redis as a dependency: https://t.co/7y5lXdlC0Q

#RailsWorld

[MagmaLabs @weareMagmaLabs]

Excited to announce that the MagmaLabs team is already in Amsterdam for the big event #RailsWorld ! 🌍🚀

[MagmaLabs @weareMagmaLabs]

🎉 We are excited to be part of #RailsWorld2023 and contribute to the growth and development of the @rails community.
🚀 This event is a great opportunity to share knowledge and build valuable connections. 🤝

Stay tuned or you will miss it 👀

[Ruby on Rails @rails]

SolidCache is a new database backed ActiveSupport cache developed at @37signals which gave them increased cache size, longer expiry time, reduced costs, and quicker email rendering times. Donal McBreen will tell you all about it in his talk at #RailsWorld https://t.co/R0MTChLhkt

[Ian Zelbo @ianzelbo]

This needs to be the standard