Leonardo Zamariola

PostgreSQL (and most of other databases) essentials for backend developers

Sat, 12 Sep 2026 14:07:00 -0300

This is not an extensive list. I reduced some details and specificities to the bare minimum that I think it’s required for a backend developer to know when seriously using PostgreSQL.

All the topics here are well documented in the official PostgreSQL docs

Index types, when and why Link to heading

I’m not getting into the detail of each index. What I believe that you should know is: 1) how this index is stored (how much space each one of them uses); 2) which datatypes they are supposed to perform better; 3) which operations they support

Token pagination - not everything is an offset

Mon, 07 Sep 2026 15:38:00 -0300

Why API pagination is important Link to heading

API pagination is one of those tricky details that contributes a lot to the performance of a website. I use it frequently as an acurate indicator of an interview candidate. The ones who, when defining the API contract, mention API pagination tend to be the ones who perform better later on.

KubeCon and CloudNativeCon Europe 2026 biggest hits

Thu, 02 Apr 2026 19:01:00 -0300

The KubeCon and CloudNativeCon took place from March 23rd to 26th in Amsterdam (hosted in the RAI Amsterdam). The event was massive, with more than 13,000 attendees (a bump of more than 10% compared to last year’s edition).

The first day (Monday) was dedicated to the co-located events and most of the knowledge paths were touching AI topics (I picked the Cloudnative AI + Kubeflow day, btw). The next three days were the main “official” keynotes and even though I tried my best to dodge the sketchy AI propaganda, most of the talks I attended mentioned a little bit of AI here and there.

What is the SOLID pattern and why you should avoid it

Sat, 23 Aug 2025 18:09:27 -0300

What is SOLID Link to heading

The SOLID is an acronym created in 2004 based on principles that Uncle Bob introduced in the 2000s to identify the best practices of software design.

💡 Disclaimer: I’m not giving a full description of the SOLID pattern because a lot of folks have done that. Digital Ocean has done that and the Uncle Bob himself has done that

Although the SOLID principles may apply to any object-oriented design, they usually bring with them the Clean Code and Clean Architecture philosophies.

The 3 main reasons why golang is the future of backend development

Tue, 27 May 2025 21:54:00 -0300

The future of development brings many innovations with artificial intelligence, autonomous agents, and dedicated edge hardware. Golang has a short learning curve, consistency across domains, and fast build times — three of the main drivers of productivity. (See more in the video below)

Como iniciar na carreira de desenvolvedor de software

Tue, 18 Jun 2024 18:09:01 -0300

Como iniciar na carreira de desenvolvedor de software Link to heading

Ainda vale a pena ser um programador? Link to heading

A carreira de desenvolvimento de software teve um crescimento gigantesco nos ultimos anos. No final do seculo passado havia somente os processadores de dados e quase todo o foco de desenvolvimento era para aplicações desktop. A internet ainda caminhava a passos lentos e os telefones, além de ligacoes, apenas enviavam SMS.

Staff Engineer Book and why you should read it

Mon, 20 Dec 2021 22:53:00 -0300

If you are:

Looking for a new book to read during the holidays.
A senior software engineer looking for an opportunity to grow to staff/principal.
A staff/principal/distinguished software engineer trying to fit yourself into this new career model or be better at it.

I have a great recommendation for you: Staff Engineer: Leadership beyond the management track by Will Larson. You can find it on its website and on Amazon

My Kubernetes Certifications and why you should be a certified professional

Thu, 18 Nov 2021 10:00:00 -0300

The context Link to heading

I’ve never been a huge fan of IT Certifications. I tend to believe that one’s ability to search for information associated with a good practical expertise is much more valuable than plain memorization. On the other hand, some certifications force us to go the extra mile and to study an unusual topic. That singularity captivates me. Following that path, these last months I focused on two different Kubernetes certifications: CKA (Certified Kubernetes Administrator) and CKAD (Certified Kubernetes Application Developer). Even though I wouldn’t call myself a DevOps/SR engineer, they seemed to be the natural path for an application developer working with containers and cloud computing. By the way, I strongly recommend taking these two, specially the CKAD because “Earners of this designation demonstrated the skills, knowledge and competencies to perform the responsibilities of a Kubernetes Application Developer. Earners are able to define application resources and use core primitives to build, monitor, and troubleshoot scalable applications and tools in Kubernetes”.

CI&T Meeting - Golang Getting Started and Best Practices

Sun, 29 Aug 2021 21:42:00 -0300

What it’s about Link to heading

Video and Slides from the CI&T Meetup 2021 Aug edition.

The source code can be found here

TDC Innovation - Golang in Digital Surgery and Integration with Medical Devices

Thu, 25 Mar 2021 10:13:13 -0300

What it’s about Link to heading

Slides from the TDC Innovation 2021 edition.

On this talk I touched some topics related Digital Surgery and Medical Devices Integration. It explains how we created a FHIR, DICOM and HL7 ADT Integration using plain Go protocols and resources.

The source code can be found here

TDC Recife - From OOP to High Order Functions

Fri, 30 Oct 2020 13:09:13 -0300

What it’s about Link to heading

Slides from the TDC Recife 2020 edition.

On this talk I touched some topics related to a past experience moving from OOP to High Order Functions in Go. Our team was used to Java using plain Object oriented and they had to move to Golang. Righ after the transition phase they were coding using a more procedural/OOP approach, but after a couple of weeks the code evolved to a more idiomatic Golang.

Why you should be using Ansible

Sun, 24 May 2020 18:16:13 -0300

What Ansible is and what it isn’t Link to heading

Ansible can be categorized as a Devops Automation Tool and a Configuration Management Tool. Redhat defines it as:

Ansible delivers simple IT automation that ends repetitive tasks and frees up DevOps teams for more strategic work. — Ansible website

I’m assuming that you’re familiar to the concepts of devops, infrastructure as code and configuration management, so I’m not going to detail them here.

Application, Evolution and Monitoring

Wed, 28 Aug 2019 23:01:00 -0300

The essence of software development Link to heading

I have already written here, that when we start coding the most important thing that we should keep in mind is maintainability. Even with other methods than scrum, like waterfall or “perfect planning”, it’s really hard to know beforehand exactly how to develop your system/application. So, if you want to deliver a good software and a great experience to your customers, you should invest time and energy building a high flexible system.

Why and how you should code to interfaces - and high-order functions

Thu, 16 May 2019 18:16:13 -0300

One famous debate that emerges in every design discussion is about interfaces. As always, each programmer has a different conception about it and it’s something almost inevitable to spend hours arguing about. Even when the discussion isn’t about whether or not we should use it, it’s about how to use it. As a programmer, I have my own opinion as well. I expect to give you an overview about the importance of interfaces when you should or not use it, and what you can apply it to.

Takt Time - How to pick the right technology stack

Wed, 08 May 2019 20:32:13 -0300

What’s takt time and why should you care about it? Link to heading

Every time we start a new project, a startup or even a little app, we are faced with a big decision: which technology we should use. Usually, we programmers choose our infrastructure, frameworks and programming languages (tech stack) based on what we think will make ourselves happier. However, that selection approach based on feeling may not result in the most assertive decision.

How to Start Writing Go Code

Sun, 28 Apr 2019 09:53:03 -0300

Why you should read this Link to heading

Ok, I know we have thousands of different (and better) articles explaining how to start coding in Golang (tour of Go, Effective Go and etc). Considering it, I’m going to focus on real examples (and some code) to make your Go journey a little bit easier, i.e., how to organize your go code, how to connect to a database, how to log things and what framework options (if any) to consider.

Hybris Good Practices I

Tue, 26 Jun 2018 21:01:44 -0300

1) Name your classes/interfaces with specific names instead of “Default” or “YourCustumer” prefix. Link to heading

First of all, we have to keep this important thing in mind: we are coding general and abstract business and technical rules. “Coincidentally”, these rules are being used by our customer. (To make things clear, the customer here means the company that are paying you (or your employer) to customize the hybris).