Agustin Mendez, Tech @ Nubank
Hijacking DNS with GitHub and Cloudflare

A couple of weeks ago, searching for links to one of my projects, I stumbled upon an interesting GitHub profile. It was full of repositories named dc-###########.[domain.com] and with a CNAME file to them. And my domain was present in there, and it was working.

A home-made record player

Somehow I thought building a custom record player from scratch would be a good idea. It ended up taking 7 years in the building and many many iterations. Here is a photographic record of the process.

Encrypted .rc files and secure shells

Working with several workstations and shared dot-files with lots of credentials and configurations doesn’t feel very secure nowadays. There have been libraries that steal your credentials and environment variables during the installation process. No bueno.

Bootstrapping the Lys compiler

Self hosting a compiler may be the ultimate goal of every new language.

Lessons learned designing APIs

Simple personal rules to avoid common mistakes and foster consistency while designing HTTP APIs.

Lys devlog #1

Lys compiler CLI, playground and roadmap.

Lys: A language that compiles to WebAssembly

Back in 2017, I wanted to learn WebAssembly, so I started investigating about it. The lack of good material led me to learning “the hard way”, breaking every repository I found.

Having spent hundreds of hours behind the keyboard, flights, trains, and endless toilet-hours thinking about this project, it is difficult to start writing about it.

Neural networks 101

The purpose of this article is to serve as an introduction to understand what Neural Networks are and how they work, without all the heavy math.

Engineering principles

Here is a brief list of engineering principles that guide my work

Implementing the native functions in DataWeave

In the journey to build a good useful language, we decided to enforce consistency wherever we can. To achieve this, one of the fundamental steps was to get rid of the hardcoded operators.

Calculating PI using streams, head & tail in DataWeave

Thanks to [head ~ tail] in DataWeave 2.0 we can easily create infinite sequence generators.

What is the dollar sign in DataWeave?

TL;DR: It is an argument of an automatic function injection


Bio

Agustin Mendez

Agustin Mendez is a programmer, inventor and furniture maker.
In 2008 he started contributing to open-source projects for an Argentinian game: Argentum Online, in 2009 he released open-sourced the first DirectX8 version of the game.

In 2011 he joined Soflex, a company focused on security products and location-based solutions, in the company he worked on tracking systems that are now deployed in Antarctica helping scientific expeditions and are part of many 911 emergency systems in Argentina.

In 2016 he joined MuleSoft as a Software Engineer and developed many internal tools and prototypes and part of the programming language DataWeave.

In 2018 he joined Decentraland as a Technical Leader, to create a novel gaming platform owned by its users.

In 2019 he started working as a Technical Manager at Nubank, at the moment, the fastest growing digital bank in Latin America, he was in charge of training new hires in Clojure and functional concepts, also in charge of the technical management of a new vertical of the business.

Agustin is the creator of the Lys Programming Language, this blog, several open source projects several pieces of furniture and a lot of interesting things behind NDAs.