About me

My name is Marcio Frayze David and I am the author of the project segunda.tech. You can read the articles I wrote in english here.

I have been developing software for over a decade and have been working as a systems analyst at the Brazilian Federal Data Processing Service (SERPRO) since 2009, where I help several teams to implement solutions for clients such as the Brazilian Internal Revenue Service (Receita Federal) and the National Traffic Secretariat (SENATRAN).

One of the projects I helped develop was the Digital Transit Wallet (CDT) App.

Although I spend most of my time developing softwares for the backend, I also develop frontends and mobile apps (for iOS and Android).



This programming language has been present for most of my career and I keep studying it and perfecting my skills.


Main language I use to develop frontends together with with vue.js, hyperapp and react.

Flutter / Kotlin / Swift

I had the opportunity to participate in the development of some mobile applications using various technologies, the main one being the framework Flutter.


I really like this language and I’m the creator of the course Clojure: Introduction to Functional Programming.


In the past I have used this language a lot and even created a web framework with it.


Although I haven’t used it in any major project, this is my favorite programming language and I really admire its community.


I’m still new to this language, but I’m currently studying it through the book Programming Phoenix.


I’m new to this language, but I admire the ideas and conceptions behind it. Studying it has helped me better understand the functional paradigm and have helped me become a better programmer in general.

Docker / Kubernetes

I work with DevOps practices, which requires a certain knowledge in this technologies, but it’s a subject I’m still on an intermediate level.


I listed just a few of the various technologies I studied throughout my career, but I’ve always prioritized the concepts above all else. So, I pay special attention to the studies of paradigms and good programming practices.
For many years my focus was on object-oriented programming, but in recent years I have also begun to study a lot about the functional paradigm.
In addition, I am interested in extreme programming (XP) and software architecture.


I keep up to date through several different sources, including taking online courses on platforms such as Alura, PluralSight, Coursera and egghead.io, but my favorite source still remains the books. That’s why I created a podcast to talk only about the books that influenced my career. I am also one of the founders of p de Podcast (p is for Podcast), a podcast (in brazilian portuguese) where we talk about Software Architecture and good programming practices.


Title: Brief history of Agile in Brazil.
Event: Guest in the Hipsters ponto Tech Podcast #295.
Local: Online (during quarantine).
Date: 2022/03/08.
Link: https://hipsters.tech/breve-historia-do-agile-no-brasil-hipsters-ponto-tech-295

Title: Architecture and Systems Practices without Downtime.
Event: Guest in the Hipsters ponto Tech Podcast #290.
Local: Online (during quarantine).
Date: 2022/01/02.
Link: https://hipsters.tech/arquitetura-e-praticas-de-sistemas-sem-downtime-hipsters-ponto-tech-290

Title: The use of Flutter in the Brazilian Digital Driver’s license.
Event: Flutter Brasil 2021.
Local: Online (during quarantine).
Date: 2021/09/17.
Link: https://youtu.be/OSex7G3wXg4?t=9071

Title: Flutter and Java at Serpro (Brazilian Federal Data Processing Service).
Event: Guest in the Hipsters On The Road Podcast #59.
Local: Online (during quarantine).
Date: 2021/06/04.
Link: https://hipsters.tech/flutter-e-java-no-serpro-hipsters-on-the-road-59

Título: The backstage of the Digital Traffic Wallet App (CDT).
Evento: The Developers Conference (TDC) Innovation. Stadium track.
Local: Online (during quarantine).
Data: 25/03/2021.
Link: https://www.youtube.com/watch?v=_IMXkedQdHg

Título: Deploy Friday afternoon.
Evento: The Developers Conference (TDC) Innovation. Code Design and XP track.
Local: Online (during quarantine).
Data: 25/03/2021.
Link: https://www.youtube.com/watch?v=RWMvKt-rn8A

Title: The backstage of the CDT (Digital Traffic Wallet) app.
Subtitle: How was the implementation of a flutter App for 8 million users.
Event: Science and Technology Week, Federal Institute of Mato Grosso do Sul (IFMS).
Local: Online (during quarantine).
Date: 2020/10/21.

Title: Design Patterns in the real world.
Event: Presentation for Computer Engineering students at USP.
Local: Online (during quarantine).
Date: 2020/05/28.
Link: https://www.youtube.com/watch?v=MXA3aI7Er74

Title: Migrating from native to Flutter: How to not go crazy?
Event: Tech Week.
Track: Frontend.
Local: FATEC (Faculty of Technology of the State of São Paulo). Rua Frederico Grotte, 322, Jardim São Luís - São Paulo.
Date: 2020/03/04.

Title: Starting to do continuous integration effectively.
Event: TDC (The Developers Conference) 2019 São Paulo.
Track: XP (eXtreme Programming).
Local: Universidade Anhembi Morumbi. Rua Casa do Ator, 275, Vila Olímpia - São Paulo.
Date: 2019/07/19.

Title: Finding outdated dependencies or security flaws in Java application.
Event: TDC (The Developers Conference) 2019 Florianópolis.
Track: Java.
Local: CentroSul. Av. Gov. Gustavo Richard, 850, Centro - Florianópolis.
Date: 2019/04/24.

Title: Developing mobile apps and games (J2ME) using Free Software.
Event: FLISOL (Festival Latino-americano de Instalação de Software Livre).
Local: Faculdade Rio Branco. Av. José Maria de Faria, 111 - São Paulo.
Date: 2009/04/25.

Academic background

Master’s degree

Electrical Engineering (with emphasis on Artificial Intelligence) at the Presbyterian Mackenzie University in 2010.
Dissertation title: A bioinspired algorithm for data grouping.
Available for download here.


Computer Science at Pontifical Catholic University of São Paulo in 2005.

Articles in scientific journals

Event: AI*IA 2009: Emergent Perspectives in Artificial Intelligence. XI Conference of the Italian Association for Artificial Intelligence, 2009, Reggio Emilia.
Title: A New Clustering Boids Algorithm for Data Mining.
Available for download here.

Event: Brazilian Congress of Automatic - CBA 2010, 2010, Bonito - MS.
Title: An Artificial Life Algorithm for Data Grouping.
Available for download here (66755_1.pdf file).

You’ll find more information about me at my linkedin page.