In 2026-05-27 I did my real deployment to production. In 2026-05-28, I did my first rollback.

It was a bittersweet experience because of course I’d rather deploy perfect code instead of having to revert to a previous working version, but truth is I learned a lot more because of the rollback.

Let me try and explain what happened in this wannabe post-mortem blogpost.

The requested feature

My task was simple: to adapt a system to be able to deal with a new kind of identification the brazilian government will start to issue in July 2026: the alphanumeric CNPJ (Cadastro Nacional de Pessoas Jurídicas).

I have a Google Keep note where I keep a list of things that I want to write about. Naturally, most of the items there are about things that happen at work. I must be honest: I was not expecting to be exposed to this myriad of technologies and situations in this speed. Every week feels like a month of learning. Well, “learning”. I barely have time to take stock of things I encountered and write about them - that is when I really feel I have learned. Well, let’s write, then.

It has been almost a month since I last wrote here. Things are moving pretty fast and I still did not figure out a healthy rythm of working, living, relaxing and writing. I’ll get there, though.

One of the things that almost always occupy my mind is the question: what should I write about next? There are a lot of things that I want to write about, but not so many that I feel have reached a level of maturity in my own mind in order for something minimally good to come out of it.

So, I’m back after a week since I wrote the last post. I’m making an effort to keep the momentum in the blog going.

In the same fashion of this post, I’m going to write about a take-home challenge that was proprosed to me as part of an application to work in a FinOps startup. I ended up not being selected - but my solution of the challenge was not the problem (at least, it did not seem so when I presented it).

It’s been a while since I last wrote on this website. Some things changed a lot, others stayed the same.

When it comes to change, I think the major one is that a got my first job as a software developer. And this is a big deal because, after all, I left a tenured and well paying job at the public sector to two years of software engineering without being certain if this was the right call. Deep down I felt I could do this transition, but yet, it is a little bit terryfing. Also, in the middle of this transition, the generative AI became really powerful, specially when it comes to programming.

Recently I applied for a software engineering position in a team that does integration between third-party software and a proprietary system. One of the stages of the selection process was a take-home challenge that, as I undertand, mimics a lot of what is done on a day to day basis on the job.

We have two systems: a customer system (let us call it CS) that reads and writes JSON and the proprietary system (PS) represented by a MongoDB instance. The missing link is the software I had to write, the middle layer: a program whose responsability was to translate and sync messages from CS to PS and vice-versa. The challenge was to write such program in a fashion that would make it simple to add other third-party systems in the future. Extra points for error handling, clear logging, testing.

As stated on the previous post, this domain balealabs.com was purchased from Cloudflare’s registrar. Even though it is not mandatory, it is very convenient to use Cloudflare’s Domain Name Server (DNS for the intimate) as authorative for this domain. Besides that, Cloudflare free plan has a lot of very nice features.

One of these features is that Cloudflare acts as a reverse proxy for our origin server (the nginx instance running on EC2). This means that every request made from anyone on the internet first goes through Cloudflare and only Cloudflare talks directly to our server. This has a nice side effect that Cloudflare can cache the website’s content. So, sometimes when someone visits this website, the content is served from Cloudflare’s cache, sparing our webserver. Another side effect is that the Cloudflare handles the internet facing certificate renewal. The certificate used between the origin server and Cloudflare does not need to be renewed very often (in fact, its validity is 15 years).

Just to keep the daily streak of content going (the about section was written yesterday), this post verses about the nitty gritty aspects of how this site come to be, one request at a time.

First of all, as of now, this is a fully static website, meaning that it is just html, css and javascript that goes from server to the client (your browser) and stays there. There is no back and forth between the site (a front-end, if I may) and a backend of any kind. In the future, however, I would like this to be a web application (for my own pedagogical reasons).

Not everything has a beginning, but this blog starts here.

This website aims to be a storage, a repository, a portfolio, a collection of things generated, curated and liked by me: iury.

I am a former economist who worked during 9 years on the Brazil Stock and Exchange Commission and has transitioned into the software development industry.

I intend to document all aspects of this career transition and all tech subjects that interest me in this website. Expect posts on the hosting setup, traffic data analysis, leetcode questions, software architecture and possibly some gaming and other stuff.