Antonio Ricardo Leao de Almeida, Developer in Teresina - State of Piauí, Brazil
Antonio is available for hire
Hire Antonio

Antonio Ricardo Leao de Almeida

Verified Expert  in Engineering

Back-end Developer

Teresina - State of Piauí, Brazil
Toptal Member Since
March 15, 2022

Antonio is an IT professional with over ten years of experience developing web solutions. He prefers using Java and Spring Boot when working on the back end and Angular for the front end. Antonio follows the Agile methodologies, especially Scrum, and has good communications skills.


Angular, Java, SQL, Linux, JSF, Jakarta EE, WildFly, Apache Tomcat, Git, REST...
Tribunal de Contas do Estado do Piaui
Java, JSF, SQL Server 2005, Angular, Spring Boot, REST, Spring, Scrum, Java EE...
OOP Designs, Object-oriented Programming (OOP), Java, UML, Relational Databases...




Preferred Environment


The most amazing...

...thing I've developed is the back end, front end, and mobile application to allow travelers to rent home kitchens.

Work Experience

Software Developer

2005 - PRESENT
  • Developed a system for a vaccination clinic located in six cities to control vaccine stock, schedule patients and appointments, and control payments. The system was developed in Angular, Spring Boot, and PostgreSQL.
  • Built a system for generating accounting data for automated submission to an audit company in XML format, using Java, Spring Boot, and Spring Batch.
  • Created a system for making personal kitchens available for rent. The system has integration with a credit card company to receive payments. It was developed in Angular, Spring Boot, and React Native.
Technologies: Angular, Java, SQL, Linux, JSF, Jakarta EE, WildFly, Apache Tomcat, Git, REST, Spring, MySQL, Scrum, Docker, Java EE, Unix, Transmission Control Protocol (TCP), Ubuntu Linux, JSON REST APIs, Back-end, Object-oriented Programming (OOP), Hibernate, UML, Google Cloud Datastore, Microservices, Relational Databases, Object-relational Mapping (ORM), Kubernetes

IT Director

2005 - 2019
Tribunal de Contas do Estado do Piaui
  • Developed a system to receive accounting data from 224 different cities and the state government.
  • Used BI tools to consolidate data and find anomalies.
  • Eliminated the need to receive thousands of papers from the cities.
Technologies: Java, JSF, SQL Server 2005, Angular, Spring Boot, REST, Spring, Scrum, Java EE, Unix, Transmission Control Protocol (TCP), Ubuntu Linux, VMware, JSON REST APIs, Back-end, Networking, Hibernate, UML, Relational Databases, Object-relational Mapping (ORM)


2005 - 2006
  • Taught a computer science undergraduate course in the disciplines of analysis and object-oriented programming with UML and Java programming.
  • Trained more than 100 students during the period as a teacher.
  • Mentored about ten students in their undergraduate work.
Technologies: OOP Designs, Object-oriented Programming (OOP), Java, UML, Relational Databases, Object-relational Mapping (ORM)

Owner | Developer

1994 - 2005
  • Founded the first internet service provider in Teresina, Piaui, using Unix and Linux SO with external modems and regular telephone lines. It specialized in networks (design and installations), training, and software development.
  • Created web pages using regular HTML and CGI to integrate live data.
  • Developed many systems using Delphi/Pascal for the desktop environment and SQL servers in the client/server platform. The most sold and used one was an accounting system for small and medium companies.
Technologies: Linux, Networks, Apache, Delphi, SQL, Unix, Transmission Control Protocol (TCP), Networking


1992 - 1994
  • Worked on a software project in a mainframe environment to control vehicle licensing in the state of Piaui.
  • Oversaw the downsizing of mainfraframe applications for client/server environment.
  • Installed and configured the client/server network environment, especially Novell networks.
Technologies: ADABAS, NATURAL, COBOL, C, Mainframe, SQL, Transmission Control Protocol (TCP), Object-relational Mapping (ORM)

Apron App

I worked as a full-stack developer using Java Spring Boot, Angular, and React Native to develop a solution that offered kitchens for rent and allowed travelers to search, rent, pay, and get directions to the kitchen.

PCQ Soft

Developed a software called PCQ to implement Q methodology.
Q Methodology (Q) is a complete methodology that involves technique (sorting), method (factor analysis), philosophy, ontology, and epistemology. Q reveals and describes divergent views in a group as well as consensus. Q was created by William Stephenson (1902-1989), who held PhDs in physics (1926) and psychology (1929) and studied psychometrics with Charles Spearman, the creator of factor analysis. The project was developed with Michael Stricklin and was sold to many countries.


I participated as a lead developer in developing an application for extracting accounting data from the city of Teresina, exporting it to the XML format defined by the control company (audit). Considering the large volumes of data and the maximum response time desired, we used the Spring Batch framework.

Vaccine Control System

I developed a vaccination control system for a company with five clinics in different cities. All data should be consolidated, following the vaccine stock of each branch (considering expiration dates), patient scheduling, vaccination history, payments, care, and follow-up.

Tax system

I worked on a system development project to control the issuance of electronic invoices. The system aimed to download and normalize data from all invoices issued within the state of Piaui to other states and from other states to the state of Piaui. The normalized data were analyzed and anomalies were identified for collecting the tax due. The transaction volume was around 100 million items per month.

Newspaper Publications

I developed a system for receiving requests to publish documents in newspapers. The system received PDF documents and exported each page in the image format necessary for editing software with an identifier number in each image that allowed identifying the effective publication of the document.

Budget System

I developed a price composition system for budgets for a pre-molded factory. The system projected a price based on the necessary inputs (materials and labor) of each item that was part of the project.

Help system

Developed a mobile system (Android) to request help in case of emergency. The user presses a sequence of buttons, and an SMS is sent to the list of people on his emergency contact every 30 seconds.

Converge Open Market

An Angular app as the front end and Java Spring Boot as the back end. I used Amazon Redshift for the data repository, Redis for the cache, and Amazon OpenSearch Service— previously Amazon Elasticsearch Service—for indexing data. The project aimed to estimate shortages in the electronics open market based on clients' bills of materials (BOMs) and help better estimate the supply chain system.


An Android app developed in Kotlin and Spring Boot as the back end. The app was supposed to allow clients access to restaurant menus when their GPS position was inside the restaurant, place orders directly to the kitchen, and have them delivered to their tables.
2016 - 2017

Master's Degree in Database

Boston University - Boston, MA, USA

2000 - 2002

Master's Degree in Computer Networking

Universidade Federal de Pernambuco (UFPE) - Recife, Pernambuco, Brazil

1988 - 1991

Bachelor's Degree in Computer Science

Instituto Tecnologico de Aeronautica (ITA) - Sao Jose dos Campos, SP, Brazil


Professional Scrum Master I


REST APIs, React, JPA 2, jQuery, Node.js


Apache, WildFly, Apache Tomcat, Git, VMware, Sonar


Spring Boot, Angular, Spring, JPA, Hibernate, Spring Batch, JSF, React Native


Object-oriented Programming (OOP), Object-relational Mapping (ORM), REST, Scrum, Microservices, Microservices Architecture, Mobile Development, Business Intelligence (BI)


Java, SQL, XML, TypeScript, HTML, CSS, UML, Delphi, NATURAL, COBOL, C, Object Pascal, JavaScript, CSS3, Kotlin


Relational Databases, PostgreSQL, Databases, SQL Server 2005, MySQL, ADABAS, Sybase, Google Cloud Datastore, Elasticsearch, Redis, Redshift


Unix, Jakarta EE, Ubuntu Linux, Android, Linux, Docker, Java EE, Oracle, Amazon Web Services (AWS), Kubernetes


Software Development, JSON REST APIs, Back-end, Networking, Full-stack Development, Transmission Control Protocol (TCP), APIs, Full-stack, Networks, Mainframe, Statistics, SSL Certificates, GPS, Mobile GPS, OOP Designs, Scrum Master, Data Analytics, Message Queues, CI/CD Pipelines

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.


Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring