Walter is available for hire
Hire WalterWalter Paixão Cortes
Verified Expert in Engineering
Data Engineer and Power BI Developer
Porto Alegre - State of Rio Grande do Sul, Brazil
Toptal member since May 30, 2017
Bio
Walter is a senior data analyst with 25+ years of experience. He's proactive, focused on results, always has the customer in mind, and is an expert in troubleshooting issues. Walter has worked on a variety of projects ranging from small to large, local or global—using project management techniques like Scrum.
Portfolio
Future-IQ
Python 3, Tableau, PostgreSQL, Google Sheets, Google Sheets API...
Guardian Restoration Partners Buyer, LLC - Main
Microsoft Power BI, Fabric, SQL, Data Engineering, Business Intelligence (BI)...
Radio Design Labs, LLC
Microsoft Power BI, Python, Data Engineering, Data Analysis, Excel VBA
Experience
- Data Integration - 20 years
- SQL - 20 years
- API Development - 20 years
- Data Analysis - 10 years
- Python 3 - 10 years
- Data Modeling - 10 years
- Tableau - 8 years
- Microsoft Power BI - 3 years
Preferred Environment
Linux, GitHub, Visual Studio Code (VS Code), MacOS
The most amazing...
...solution I've delivered is a chatbot to be used in a classroom that connects to bioinformatics databases and allows users to query them using natural language.
Work Experience
Data Engineer
2018 - PRESENT
Future-IQ
- Created an automated pipeline in Python to retrieve the data from the surveys and transform them into insights.
- Automated the creation of basic visualizations with Tableau.
- Created automated network maps using Python and D3.js.
Technologies: Python 3, Tableau, PostgreSQL, Google Sheets, Google Sheets API, Dashboard Development, Data Engineering, Business Analysis, Business Requirements, API Development, Supabase, Software Development, Excel VBA, Analytics, Database Backups, Infrastructure as Code (IaC), Fabric Lakehouse, Database Modeling, Data Warehousing
Power BI/MS Fabric Developer
2026 - 2026
Guardian Restoration Partners Buyer, LLC - Main
- Developed an ETL pipeline using PySpark for HR data.
- Built a subject area in the warehouse semantic model for HR data.
- Developed an HR dashboard in Power BI, with several HR KPIs.
Technologies: Microsoft Power BI, Fabric, SQL, Data Engineering, Business Intelligence (BI), SharePoint
Python and Power BI Data Analyst
2025 - 2026
Radio Design Labs, LLC
- Developed a pricing list application to help update prices on the sales system.
- Created a sales dashboard in Power BI connected with the sales system.
- Built a near-real-time dashboard in Power BI to help production teams.
- Created the sales commission dashboard to help RDL Net pay sales teams and representatives.
Technologies: Microsoft Power BI, Python, Data Engineering, Data Analysis, Excel VBA
Power BI Expert
2025 - 2025
Simba Cal, Inc.
- Fixed more than 20 dashboards to modernize the data source and ensure auto refresh.
- Created a new Power BI dashboard for Phone Central.
- Automated data pipeline using Power Automate, to put together a new data source for Phone Central.
Technologies: Data Analytics, Data Visualization, Microsoft Power BI, Acumatica, Hotjar, HubSpot, Microsoft Excel, Data Analysis, Analytics, Fabric Lakehouse, Database Modeling
API Developer
2024 - 2025
IoFMT Professional Services LTD.
- Researched how to integrate SFG20 and other facilities systems.
- Developed a REST API in FastAPI, with PostgreSQL back end, to connect to SFG20 and create a cache for a Power App.
- Developed two custom connectors on Power Platform to connect with the REST API.
- Deployed the API on Azure as a fully monitored App Service.
Technologies: API Integration, API Development, APIs, Microsoft Dataverse, Windows, Azure, Python, Flask, FastAPI, Software Development, Database Backups, Database Modeling
Data Analytics Practitioner
2024 - 2024
Brigit
- MIgrated multi-purpose dashboards from the Sisense tool to Mode.
- Reviewed and modified SQL queries to adapt to the new tool and improve performance.
- Adapted the charts on the new tool to the design requirements established by Brigit.
Technologies: Data Build Tool (dbt), Data Visualization, Snowflake, SQL, BI Reporting, Dashboard Development, Sisense, DevOps, Business Requirements, Microsoft Power BI, Analytics, Segment, Database Modeling, Data Warehousing
Power Platform Consultant
2023 - 2024
Panthera Global Carbon
- Developed Power App to support engineers to record information related to tests.
- Modeled the Power App data source using Dataverse.
- Designed a Microsoft PowerBI dashboard for visualizing insights from the data generated.
Technologies: Microsoft Power Apps, Microsoft Power BI, Microsoft Excel, Dashboard Development, Business Analysis, Business Requirements, API Development, Software Development, Visual Basic for Applications (VBA), Looker, Analytics, Database Backups, Database Modeling
Tableau Dashboard Analyst
2023 - 2024
Cosgrove Partnership Inc
- Created dashboards in Tableau for transition analysis.
- Made small ETL pipelines using scheduling procedures in BigQuery.
- Created SQL routines to assess the data quality of the source tables.
- Migrated all code to dbt and organized the minimum DevOps footprint.
Technologies: Tableau, Dashboards, Data Visualization, Dashboard Design, Google Sheets, Google BigQuery, Microsoft Excel, Dashboard Development, Data Build Tool (dbt), DevOps, Data Engineering, Business Analysis, Business Requirements, Supabase, Google Cloud, Database Backups, Google Cloud SQL, Database Modeling, Data Warehousing
Power BI Expert
2023 - 2024
DSA INTERNATIONAL HOLDING COMPANY, LLC
- Developed and maintained sales dashboards using Power BI.
- Created a new data analytical model to improve performance, precision, and conformance with the KPIs of the area.
- Created the data catalog to keep track of the data that is being added to the analytical data model.
Technologies: Microsoft Power BI, Microsoft SQL Server, SQL Server BI, Microsoft Excel, Dashboard Development, Business Requirements, Supabase, Software Development, Database Modeling
BI Specialist
2023 - 2023
Flight Level LLC
- Parsed historical sales data and historical fuel sales data from Excel and PDF files into a database (DuckDB) to gather all the information. After all the data is collected, it is exported to a Parquet file.
- Created the sales and fuel sales dashboards in Microsoft Power BI. The dashboards use dynamic filters that change the X and Y axis of the main charts, making it possible to see different data views.
- Conducted performance tuning in refreshing data in Power BI due to the high volume of data.
Technologies: Business Intelligence (BI), Data Analysis, Data Visualization, Dashboards, Microsoft Power BI, Tableau, Google Data Studio, Dashboard Development, REST APIs, Business Analysis, Business Requirements, API Development, Software Development, Database Modeling
Power BI Expert
2023 - 2023
Marcel Harris
- Developed a data model from the data provided by the customer, a US-based company.
- Created several dynamically calculated KPIs for sales.
- Designed the dashboard based on the Figma prototype.
Technologies: Microsoft Power BI, Dashboard Development, Business Requirements, Database Modeling
Data Engineer
2023 - 2023
Green-Wood Cemetery
- Created an automated pipeline to populate Elasticsearch index.
- Stabilized the process of importing data into Elasticsearch.
- Created automated GitHub Actions to process the Excel files and activate the Elasticsearch pipeline.
Technologies: Python, Elasticsearch, JSON, JavaScript, Node.js, DevOps, REST APIs, Data Engineering, Business Requirements, API Development, FastAPI, Software Development, Database Backups, Database Modeling
Data Visualization Expert
2023 - 2023
A-lab
- Developed a data model for project management analytics, using the output of their CAD and PLM tools as the source. Created a data model capable of showing the trend of problems that may occur in other projects.
- Created a Power BI dashboard to show the project insights and guide the support team to resolve project issues.
- Executed performance tuning on the model to ensure the best performance for queries.
Technologies: Microsoft Power BI, MySQL, Data Visualization, Dashboard Development, Business Requirements, Database Modeling, Data Warehousing
Data Engineer
2022 - 2023
R3 Development Group, LLC
- Developed a pipeline that retrieves information from an EPA government FTP site.
- Created a data model with the data collected to show the correlation among all the data files and display problems in water supplies. The data model was created with KPIs elaborated by the subject matter experts.
- Architected two dashboards with information available on the built model.
Technologies: Tableau, Data Analysis, APIs, Data Analytics, Data Science, Data Build Tool (dbt), Apache Airflow, Reporting, Dashboards, Data Structures, Data Integration, Dashboard Development, REST APIs, Business Requirements, API Development, Microsoft Fabric, Software Development, Database Modeling, Data Warehousing
Data Engineer
2022 - 2022
Scoutside, LLC
- Built a data pipeline to migrate data between two marketplace systems.
- Created a web interface using Vue to manage the execution of the data pipeline.
- Executed data corrections based on validation from the business.
Technologies: Data Engineering, MongoDB, ETL, Data Migration, REST APIs, Business Requirements, API Development, Software Development, Database Backups, Database Modeling
Product Designer
2019 - 2022
Dell Technologies
- Developed two products using a method that combines lean, user-centered design (UCD) and extreme programming (XP) to deliver fast and high-value results to our customers.
- Assisted the team in finding solutions using design-thinking techniques.
- Created user interfaces with high usability that are innovative, responsive, and reactive using Angular, Vue, and Bulma.
- Used the Python asynchronous framework FastAPI to develop the back end, supported by other technologies like Redis, RabbitMQ, and Cloud Foundry.
Technologies: PostgreSQL, MongoDB, Oracle, Bulma, Vue, Angular, Python, Python 3, Tableau, Google Sheets API, Data Modeling, APIs, VMware Tanzu Application Service (TAS) (Pivotal Cloud Foundry (PCF)), Oracle Database, Data Gathering, Data Engineering, Kanban, Dashboard Design, Data Analysis, Microsoft Power BI, Flask, SQL, Bootstrap 3, Databases, Flask-RESTful, Data Lakes, Data Analytics, CSV File Processing, Scripting, SQL DML, Business Intelligence (BI), Reporting, Dashboards, Data Structures, Data Integration, DevOps, Business Requirements, Software Development, Firebase, Database Modeling
Software Development Advisor
2009 - 2019
Dell
- Developed the human resources data lake using the Hadoop technology stack.
- Assisted the human resources data warehouse using the OBIEE technology stack.
- Supported the Oracle Web Center (OWC) technology stack for a document repository.
- Provided support for the human resources data warehouse using the BusinessObjects (SAP-BO) technology stack.
- Aided in the development of the portfolio management tools for IT.
Technologies: Python, Teradata, Oracle, Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Python 3, Google Sheets API, Web Scraping, Certified ScrumMaster (CSM), Data Modeling, APIs, VMware Tanzu Application Service (TAS) (Pivotal Cloud Foundry (PCF)), Oracle Database, Data Gathering, Data Engineering, Kanban, Data Analysis, Flask, ETL, SQL, Databases, Data Lakes, Angular, Cassandra, Azure SQL Databases, Data Analytics, CSV File Processing, Scripting, SQL DML, Reporting, Dashboards, Data Structures, Data Integration, Excel 365, Data Build Tool (dbt), DevOps, API Development, Software Development, Firebase, Salesforce, Database Modeling, Data Warehousing, Oracle Integration Cloud (OIC)
Senior Software Development
2005 - 2008
Dell
- Maintained multiple .NET applications for the Product Group (PG).
- Supported the development team as an application DBA on Oracle and SQL Server technologies.
- Led the team that onboarded IT support for more than 20 applications supported by the business, reaching 100% compliance with IT policies and standards.
Technologies: Microsoft SQL Server, Oracle, ETL, Certified ScrumMaster (CSM), Data Modeling, Oracle Database, Kanban, Flask, SQL, Databases, CSV File Processing, Scripting, Transact-SQL (T-SQL), SQL DML, Data Structures, Data Integration, API Development, Software Development, Database Modeling
Senior Software Engineer
2003 - 2005
Accenture
- Developed multiple web applications for Accenture customers.
- Acted as an application DBA on Oracle databases for Accenture customers.
- Built an ASP.NET framework to speed up and standardize the development efforts for all development teams.
Technologies: Microsoft SQL Server, Oracle, Oracle Database, SQL, Databases, CSV File Processing, Scripting, SQL DML, Microsoft Access, Data Structures, Data Integration, API Development, Software Development, Database Modeling
Senior Software Engineer
2001 - 2003
Bankorp Consultores Associados
- Developed ASP web applications for the state IRS office.
- Built ASP.NET web applications for the state government.
- Created an EAD solution in ASP.NET that was capable of importing SCORM content.
- Constructed a document store web application in ASP.NET for many customers.
Technologies: Microsoft SQL Server, VBScript, SQL, Databases, Scripting, SQL DML, Microsoft Access, Data Structures, Data Integration, API Development, Software Development, Database Modeling
Experience
Bodies of Water Analysis
I created a Tableau dashboard that shows the results of the analysis of bodies of water in the US, based on EPA data. I've also created all the ETL processes to collect, clean, and transform the raw data from EPA in actionable insights using dbt.
Tableau Visualizations
https://public.tableau.com/profile/wvcodeI created Tableau visualizations for scientific and commercial purposes, including cities research and development. I developed scripts to gather and format data and a "Design System" to guide the creation of all visualizations. Here I'm making four available that are not under NDA.
DB-InhA
DB-InhA is a bioinformatics tertiary database which contains all the relevant information to the InhA enzyme. It is divided into two streams: a responsive web application that allows querying of the information and a service that collects information and applies some basic curation techniques.
Technologies: Bootstrap, Python (Flask), MySQL
Technologies: Bootstrap, Python (Flask), MySQL
Data Migration
I have created a Python migration script between two eCommerce solutions, Conjured and OrderGroove. The challenges were related to differences in how the two systems deal with subscriptions and payments. The work required knowledge of APIs and how to use them to create a stable data conversion pipeline with capabilities to be executed several times until completion.
Riverlite Dashboard Application
I developed a dashboard application using Bootstrap and Python (Flask) to show incident management metrics and collect the data via an API from their PRTG server. The PRTG API was made available to create ETL scripts that store information in PostgresSQL.
HR Analytics
HR Analytics is a data warehouse built on top of OBIEE (Oracle Business Intelligence Enterprise Edition) and comprises ETL processes developed in Informatica Power Center. Developed the reports and dashboard in OBIEE, and it also has a database modeled on top of Oracle 11g.
wCReF Portal
wCReF is a responsive web portal to support the use of the CReF method for protein 3D structure prediction.
Technologies used: Bootstrap, Python (Flask), MySQL.
This interface was developed for a structure prediction study.
Technologies used: Bootstrap, Python (Flask), MySQL.
This interface was developed for a structure prediction study.
Education
2015 - 2020
Doctorate in Computer Science
Pontifical Catholic University of Rio Grande do Sul - Porto Alegre, Brazil
2013 - 2015
Master's Degree in Computer Science
Pontifical Catholic University of Rio Grande do Sul - Porto Alegre, Brazil
Certifications
OCTOBER 2015 - PRESENT
Certified Scrum Master (CSM)
Scrum Alliance
Skills
Libraries/APIs
Google Sheets API, OpenAPI, REST APIs, API Development, Zoho API, Flask-RESTful, Beautiful Soup, Typeform, Vue, eBay API, Paessler PRTG API, Node.js, Fabric
Tools
Tableau, Microsoft Power BI, Microsoft Access, Google Sheets, Microsoft Excel, Zapier, Looker, CAD, Oracle BI Publisher, BigQuery, GitHub, Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Apache Airflow, SQL Server BI, Microsoft Power Apps, Sisense, Acumatica, Hotjar
Languages
Python, Python 3, SQL, SQL DML, Transact-SQL (T-SQL), Snowflake, Excel VBA, Visual Basic for Applications (VBA), VBScript, JavaScript
Paradigms
ETL, Business Intelligence (BI), Kanban, DevOps
Platforms
VMware Tanzu Application Service (TAS) (Pivotal Cloud Foundry (PCF)), Oracle Database, Oracle, Windows, Microsoft Fabric, Azure, Fabric Lakehouse, SharePoint, Oracle Integration Cloud (OIC), Visual Studio Code (VS Code), Linux, MacOS, Firebase, HubSpot, Salesforce
Storage
Microsoft SQL Server, PostgreSQL, Databases, JSON, Data Integration, Database Backups, Database Modeling, Cassandra, MySQL, Azure SQL Databases, Google Cloud, Google Cloud SQL, Data Lakes, Teradata, MongoDB, Elasticsearch
Frameworks
Flask, Angular, Bulma, Scrapy, Bootstrap 3
Other
Data Modeling, Data Gathering, Data Engineering, APIs, Data Analysis, Dashboard Design, Data Analytics, Scripting, API Integration, Data Visualization, Reporting, Dashboards, Data Structures, Data Migration, Dashboard Development, Software Development, Data Fetching, Analytics, Data Warehousing, Certified ScrumMaster (CSM), Web Scraping, Data Scraping, CSV File Processing, Data Build Tool (dbt), Excel 365, Google BigQuery, Business Analysis, Business Requirements, Stakeholder Management, Microsoft Dataverse, FastAPI, Supabase, Infrastructure as Code (IaC), Oracle Fusion HCM, Screen Scraping, Scrum Master, Data Science, Google Data Studio, BI Reporting, Segment
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