Arnaldo Silva Rodrigues Junior, Developer in Curitiba - State of Paraná, Brazil
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Arnaldo Silva Rodrigues Junior

Verified Expert  in Engineering

Software Architecture Developer

Curitiba - State of Paraná, Brazil
Toptal Member Since
April 3, 2015

Arnaldo sees himself as a problem solver, given the various challenges he faced and solved in his career. An entrepreneur by nature, he's an electrical engineer with a passion for software development. This background, combined with over 20 years of experience developing full-stack web and mobile applications and fifteen years developing enterprise applications, gives him a unique set of skills to overcome every obstacle.


Toptal Client
Angular, React, Ionic, Node.js, Google Cloud Platform (GCP)...
Software Architecture, TypeScript, GraphQL, CTO, Architecture, MySQL, MongoDB...
Software Architecture, Architecture, Java, Behavior-driven Development (BDD)...




Preferred Environment

Kubernetes, Docker, Google Cloud Platform (GCP), GitLab, WebStorm, MacOS, Jira, Slack, Trello

The most amazing...

...thing I've accomplished was building a software-outsourcing company from scratch to a company with over a hundred employees.

Work Experience

Software Architect | Full-stack Developer

2014 - PRESENT
Toptal Client
  • Created a usage tracker system to record user behavior using JavaScript, Node.js, Adonis framework, and PostgreSQL.
  • Set up 2FA using Google Auth and FIDO keys for a cryptocurrency exchange startup using React, Node.js with Express using microservices concepts.
  • Created an integration between Jira and Xero to retrieve working hours and milestones information, consolidate, and input billing entries. This integration was built using Angular, Node.js, Express, MySQL.
  • Migrated a warehouse system from a JavaScript environment to an Outsystems environment.
  • Built a visual workflow of the task dependencies to produce a COVID-19 vaccine using React over Next.js.
Technologies: Angular, React, Ionic, Node.js, Google Cloud Platform (GCP), Amazon Web Services (AWS), Docker, Kubernetes, PostgreSQL, MySQL, Firebase, MongoDB, Express.js, Microservices, Mobile, Software Development Lifecycle (SDLC), Solution Architecture, JSON, ETL, CSS, CSS3, iOS, Mobile Applications, Technical Leadership, Django, Full-stack Development, AWS Cloud Architecture, React Native, User Experience (UX), User Interface (UI), NoSQL, REST APIs, Data Engineering, CI/CD Pipelines

Chief R&D Officer | Partner

2012 - PRESENT
  • Created an R&D division to develop innovative products that are the next step of the company.
  • Acted as the CFO of the company from 2018 to 2020. Created a series of KPIs and controls to ensure the financial health and profitability of the company.
  • Acted as the lead software architect of the company, team lead, and full-stack developer from 2012 to 2018, working on many projects, mainly using JavaScript with Angular, Node.js, MySQL, PostgreSQL, and Firebase.
  • Architected and led a team that built a cash-back system using the concept of double-entry bookkeeping. The web version was built using Angular, and the apps using Ionic. The back end was Node.js on AWS, using Lambda functions and Kubernetes.
  • Created new features in Volvo Finance, an iOS application to simulate monthly parcel calculation of the financing of vehicles for the Volvo Group.
  • Architected and developed VPSA ERP’s mobile for Android tablets.
  • Built billing and charging systems for VoIP providers.
  • Started and structured a software-outsourcing business in Brazil from scratch, alongside my business partner, from long-term strategic planning to hiring an office cleaner.
Technologies: Software Architecture, TypeScript, GraphQL, CTO, Architecture, MySQL, MongoDB, Express.js, Node.js, CSS, HTML, Android, Java, JavaScript, Behavior-driven Development (BDD), Agile Software Development, Neo4j, Git, APIs, MEAN Stack, Swagger, JSON Web Tokens (JWT), Agile, DevOps, Microservices, Cloud Architecture, Project Management, Angular, PostgreSQL, Full-stack, Mobile, AWS Lambda, Amazon DynamoDB, Software Development Lifecycle (SDLC), Solution Architecture, JSON, ETL, CSS3, iOS, Mobile Applications, Technical Leadership, Full-stack Development, Amazon Cognito, Mobile Apps, User Experience (UX), User Interface (UI), NoSQL, Performance, Leadership, Artificial Intelligence (AI), REST APIs, Data Engineering

Software Developer Consultant

2010 - 2013
  • Allocated as a third-party resource in GBM-HSBC Bank.
  • Led the development of the system that communicated with the Brazilian regulatory agency (ANBIMA) about investment funds and managed portfolios and the development of the system that controls the tax payment for those funds.
  • Developed the integration to report transactions between the Brazilian and Cayman Island branches to the Brazilian regulatory agency.
Technologies: Software Architecture, Architecture, Java, Behavior-driven Development (BDD), Agile Software Development, Project Management, Full-stack, JSON, ETL, CSS, CSS3, Technical Leadership, Full-stack Development, REST APIs, Data Engineering

Systems Analyst

2005 - 2010
Global Village Telecom
  • Generated network KPI reports using Excel (VBA). Developed a system to monitor the dial-up internet equipment using Perl and SNMP. Generated call center KPI reports.
  • Created tools in Excel (VBA) to support CRM and marketing strategy analysis and automated tools to monitor internet dial-up traffic.
  • Analyzed data to build BI systems for a VoIP provider and a dial-up internet provider using PL and SQL in an Oracle database.
  • Planned CRM processes and marketing strategy analyses based on the information acquired from BI.
  • Developed a CRM system using Java and Adobe Flex. Created the Click2Call system. Created a real-time online Flash component compiler.
  • Implemented improvements in the billing system of a VoIP provider.
  • Led the development of improvements in the service provisioning system and the development of a small service bus.
Technologies: Software Architecture, Architecture, Visual Basic for Applications (VBA), Java, Behavior-driven Development (BDD), Project Management, Full-stack, JSON, ETL, CSS, CSS3, Technical Leadership, Full-stack Development, REST APIs


2004 - 2005
Infomatrix Consultoria, Informática e Informação LTDA
  • Fixed bugs in a document management system for agro-industries.
  • Developed new features for the document management system using VB6.
  • Wrote SQL procedures to process information for reports in an Oracle database.
Technologies: SQL, Full-stack Development


2003 - 2004
LAX Eletrônica e Telecomunicações LTDA
  • Programmed micro-controllers in assembly language.
  • Wrote a library to create a FAT file system over an EEPROM.
  • Implemented serial communication using I2C to control peripherals.
  • Designed circuit boards and welded electronic boards.
Technologies: Microchip PIC18, PIC16, Linux, Assembly


An app to manage the sales of independent sales consultants for a cosmetic company.
I was the team lead and lead developer of the project. The system was a PWA built using Angular in the front end and Firebase to store the data.

Vono VoIP

A Brazilian VoIP provider.
I was part of the team that developed and maintained the billing system and the call routing system. It used FreeSwitch as a PBX system. The support systems were written in Java and used an Oracle database.

Volvo Finance

Cross-platform app to do financial simulations using government funding.

All simulations were first created in Excel and validated. Afterward, the calc processes were reproduced into the app.

Built using Excel (VBA) to validate the simulations and then Ionic 2 to build the app.

Buyback System

The buyback system allowed the owner of the company to look up the value of a book by scanning its barcode and keeping track of all the purchases he made; he could also process and inventory the books back at his warehouse using the same system, and eventually get them up for sale.
I was onboarded in the project when the system was 75% done, and I finished the project. The system was built using Angular, Node.js with Sails.js and deployed on S3 and Heroku.

SMS Routing System

Worked in a routing engine for SMS messages.
I improved and extended several back-end microservices in the form of Express apps. I was also part of the team responsible for maintaining the international routing system. is a SaaS platform for performing accessibility testing against websites and other web-based systems. It was built using JavaScript and Node.js with a microservice architecture.
I was part of the back end development team.


A cryptocurrency exchange.
I was part of the team that implemented security measures to avoid attacks on clients, such as 2FA authentication using FIDO keys and Google Auth. The system was built using React in the front end and Node.js in the back end.

Schedule Optimization

A system to optimize the schedule of the vaccine production of a pharmaceutical company.
I built a visual workflow to tie the task dependencies of this production. The front end was build using React over Next.js; the back end used Node.js with PostgreSQL and Redshift as databases.
2021 - 2022

Executive Program in Finance

Wharton Executive Education - Online

2001 - 2012

Bachelor's Degree in Electrical Engineering - Electronics and Telecommunications

Technological University of Paraná Federal - Curitiba, Brazil


Associate Traditional Web Developer

OutSystems Training Team


Node.js, React, REST APIs, Konva, Fabric


Git, Sequelize, Mongoose, Jira, Slack, Trello, FreeSWITCH, Auth0, Canvas, Amazon Cognito


Angular, Ionic, Express.js, JSON Web Tokens (JWT), Swagger, Django, React Native, Sails.js, Next.js


SQL, TypeScript, JavaScript, CSS3, HTML5, CSS, HTML, GraphQL, UML, Python, Visual Basic for Applications (VBA), Java, C++, x64 Assembly, Assembly, C#


MEAN Stack, Agile, Object-oriented Programming (OOP), Scrum, Behavior-driven Development (BDD), Agile Software Development, Test-driven Development (TDD), ETL, Microservices, DevOps


Amazon Web Services (AWS), iOS, Mobile, Docker, Kubernetes, Android, Firebase, AWS Lambda, Google Cloud Platform (GCP), MacOS, Heroku, Oracle, Apache Kafka, Azure, Blockchain


JSON, NoSQL, MongoDB, MySQL, PostgreSQL, Web SQL, Neo4j, Amazon S3 (AWS S3), Redis, Redshift, Amazon DynamoDB

Industry Expertise

Project Management


CTO, APIs, Cloud Architecture, Full-stack, Software Architecture, Architecture, Solution Architecture, Software Development Lifecycle (SDLC), Mobile Applications, Technical Leadership, Full-stack Development, User Experience (UX), User Interface (UI), Leadership, OutSystems, OAuth, Authentication, Artificial Intelligence (AI), AWS Cloud Architecture, Mobile Apps, Performance, Data Engineering, Serial Communication, CI/CD Pipelines, Progressive Web Applications (PWA), EJB 3, API Integration, Fintech, Digital Transformation, Digital Payments, Marketplace Lending, Consumer Banking, Insurance Technology (Insurtech), Technology, Cryptocurrency, Regulations, Real Estate

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