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Sérgio René Pessoa Vila Nova Filho
Verified Expert in Engineering
C# Developer
Madrid, Spain
Toptal member since January 12, 2016
Bio
Sérgio is a lead developer with several years of experience developing applications on the .NET platform along with a solid machine learning background. A career highlight of his is when he led development teams in efforts to improve a big, distributed, scalable, desktop app for energy market players. All in all, Sérgio is very productive, able to learn new technologies quickly, and focuses on software performance and usability.
Portfolio
Energy Company
.NET Core, REST APIs, RESTful Development, SQL Server 2015, Amazon S3 (AWS S3)...
Gemini Diversified Services, Inc.
.NET Core, SQL Server 2015, Azure, Azure SQL, Azure Cache, Azure Blobs...
Buddy Punch LLC
.NET, C#, ASP.NET, ASP.NET MVC, Vue, JavaScript, Entity Framework, Azure DevOps
Experience
- C# - 13 years
- Microsoft SQL Server - 13 years
- Oracle - 7 years
- Windows Forms (WinForms) - 7 years
- ASP.NET MVC - 6 years
- .NET Core - 6 years
- ASP.NET Web API - 3 years
- Machine Learning - 2 years
Preferred Environment
SQL, MATLAB, Visual Studio, Windows
The most amazing...
...thing I've coded is a time series forecaster which combines predictors and uses dynamic time warping algorithm. It achieved very good results.
Work Experience
Co-founder | Back-end Software Engineer
2018 - PRESENT
Energy Company
- Created a scalable back end for a web application to help energy trader companies find new customers.
- Worked actively on this app that processes data from several third-party APIs and spreadsheets containing data related to all Brazilian companies. It analyzes, filters, and treats the data, then stores it in an optimized database structure.
- Contributed to this app that creates reports to inform the users which companies could be their next customers. The reports are built in milliseconds after looking up over 10 million companies' data.
- Built the back end using .NET Core with SQL Server database, running on Amazon Web Services with Amazon ElasticCache and S3 services. It provides a RESTful API to the front end that is implemented using React.
Technologies: .NET Core, REST APIs, RESTful Development, SQL Server 2015, Amazon S3 (AWS S3), Amazon EC2, C#, C#.NET, Entity Framework Core, REST, Entity Framework, .NET, Amazon Web Services (AWS), AWS Cloud Architecture, ASP.NET Core MVC
Senior Software Engineer
2016 - PRESENT
Gemini Diversified Services, Inc.
- Implemented web applications using ASP.NET Core (.NET Core 1.0, 2.1, 3.0, .NET 6), EF Core, SQL Server. Hosted entirely on Azure. It processes the medical credentialing of 300,000+ providers with 200+ clients.
- Integrated the applications with many third-party APIs to send emails, faxes, invoices, generate PDFs, Azure AD, Bing, Azure AD B2C, license boards, etc.
- Built 20+ web crawlers to retrieve data automatically from websites that did not have an API available.
- Built a robust microservice to generate 1,000+ PDFs/day used by different applications.
- Architected Power BI reports using data stored on 200+ databases.
- Built an application to migrate 100,000+ providers' data from one system to another with a big model/logic difference.
- Developed several unit tests to assess the quality of the applications and ensure they will continue to work as expected after new developments.
Technologies: .NET Core, SQL Server 2015, Azure, Azure SQL, Azure Cache, Azure Blobs, Microsoft Power BI, jQuery, Bootstrap, APIs, SendGrid API, Entity Framework Core, Azure Active Directory Graph API, Azure Active Directory B2C (ADB2C), RESTful Microservices, Intuit QuickBooks, Unit Testing, C#, C#.NET, Entity Framework, .NET, Azure DevOps, ASP.NET Core MVC
ASP.NET MVC C# Developer
2021 - 2022
Buddy Punch LLC
- Worked on an application used by thousands of companies to do their employees' time-tracking, scheduling, and payroll safely and easily.
- Improved code reusability of an ASP.NET MVC application using Entity Framework with SQL Server database that also provides an API to a mobile app.
- Developed new features and fixed bugs on a time-tracking web application with several types of employee work hours contracts and payroll integrations with different applications like QuickBooks, Zapier, Paychex, etc.
Technologies: .NET, C#, ASP.NET, ASP.NET MVC, Vue, JavaScript, Entity Framework, Azure DevOps
Senior Software Engineer
2016 - 2017
RAAMP
- Developed new features for a commercial real estate management web application in ASP.NET MVC and SQL Server hosted on Azure, including Properties, Tenants, Accounting, and File System features.
- Migrated a big document management web application with over 400,000 indexed documents from Classic ASP to ASP.NET MVC and SQL Server. It is hosted on Azure and helps users quickly find the necessary documents.
- Improved performance on many data loads in the document management application, from minutes to milliseconds.
- Integrated the applications with several third-party APIs like SendGrid, Stripe, and Azure Blob.
Technologies: ASP.NET MVC, SQL Server 2015, jQuery, CSS, HTML, Classic ASP, Azure, Azure SQL, Azure Blobs, SendGrid API, Stripe API, C#, C#.NET, Entity Framework, .NET, Azure DevOps
Freelance Developer
2016 - 2016
Sneakerbots 4 all (via Toptal)
- Developed web crawlers for buying highly demanded products on specific store's websites.
- Refactored and organized existing code used to shop in different stores.
- Added unit and integration tests in order to immediately know when a store's website has changed and the crawler needs to be updated.
Technologies: Microsoft Visual Studio, Windows, Windows Forms (WinForms), C#, .NET
System Architect | Lead Developer
2011 - 2016
Suati
- Created a credit and volumetric risk analysis feature on a desktop application based on current energy contracts and a simulation of future contracts in 2,000 scenarios.
- Wrote a layer with aspect-oriented programming on a big desktop application to improve the capabilities of UI components when running UI tests.
- Constructed an extensible billing processing architecture for the many specific billing calculation types in the Brazilian energy market. Billing 10,000+ contracts every month.
- Developed a financial report feature that had all the company revenues and expenditures that allowed assessing energy market players' decisions.
- Created an energy accounting report feature based on energy consumption, generation, and contracts; this feature allowed for the assessment of the energy market players' decisions.
- Built the service providing fiscal document generation and integration with the government fiscal authority system.
- Led teams of up to ten people (developers and QA) to develop and deliver new features within deadlines using Scrum.
Technologies: ASP.NET Web API, ASP.NET, Microsoft Visual Studio, ADO.NET, Back-end Development, Oracle, Microsoft SQL Server, JavaScript, ASP.NET MVC, VB, C#, Scrum, C#.NET WinForms, C#.NET, Transact-SQL (T-SQL), PL/SQL, Oracle PL/SQL, .NET
Machine Learning Researcher
2013 - 2015
VIISAR Research Group, Universidade Federal de Pernambuco
- Designed and developed a novel model for predicting time series. It partitions the time series and trains predictors for each partition. With those trained predictors, it chooses the best one to forecast using a DTW (dynamic time warping) algorithm.
- Developed the model in MATLAB, and the predictors used were MLP and SVR.
- Achieved results, thanks to the solution, that were better than the conventional approaches.
Technologies: Machine Learning, MATLAB, Amazon Web Services (AWS)
Freelance C# Developer
2012 - 2012
Bemind
- Developed a Windows tray application to search and play videos from a web video database.
Technologies: Microsoft Visual Studio, Windows Forms (WinForms), C#, .NET
Software Engineering Intern
2009 - 2010
SUATI
- Developed an economy simulator feature for energy trader prospect consumers, assuring them financial economy.
- Created a tariff adjustment report feature for the Brazilian energy distributor companies based on their billings and payments, looking up 10,000+ energy contracts in the past year.
- Built a fiscal document importation feature that automatically binds the document to an energy contract so the users can manage their payments.
Technologies: ASP.NET, Microsoft Visual Studio, Windows, ADO.NET, Back-end Development, Oracle, Microsoft SQL Server, VB, C#, .NET
Experience
Energy Company
A web application where the user is able to have quick access to data from multiple sources consolidated in an easy way to support business decisions and prospect new clients. It was first designed for Brazilian energy market companies, but companies from other markets also use it and have their decisions helped by the web application energy data.
GENE
A distributed system developed in C# focused on the management of the company energy contracts, consumption and generation. It also generates several important reports and provides billing and payments features.
GENE Cloud
A web application developed in ASP.NET MVC which allows GENE users to share billing information, important documents, and some energy contract data with their clients.
Time Series Forecasting Algorithm
A time series forecasting algorithm developed on MATLAB which combines many predictors (SVRs and MLPs) and uses the Dynamic Time Warping algorithm
Bemind EAD
A Windows tray application to search and play videos from a web video database.
Education
2013 - 2015
Master's Degree in Computer Science
Universidade Federal de Pernambuco - Recife, Brazil
2007 - 2011
Bachelor's Degree in Computer Science
Universidade Federal de Pernambuco - Recife, Brazil
Skills
Libraries/APIs
LINQ, Infragistics, jQuery, Windows Forms (WinForms), Entity Framework, Aspose Components, Moq, SendGrid API, Stripe API, Azure Active Directory Graph API, REST APIs, React, Vue
Tools
Microsoft Visual Studio, TFS, Autofac, NuGet, PostSharp, MATLAB, Git, Visual Studio, Azure Active Directory B2C (ADB2C), Microsoft Power BI, C#.NET WinForms
Languages
SQL, C#, Transact-SQL (T-SQL), C#.NET, XML, XSD, CSS, HTML, JavaScript, VB, PHP, Visual Basic .NET (VB.NET), R, Java, C++
Frameworks
Entity Framework Core, ASP.NET MVC, ADO.NET, ASP.NET, .NET Core, ASP.NET Web API, ASP.NET MVC 6, .NET, ASP.NET Core MVC, Classic ASP, Entity, Windows Presentation Foundation (WPF), Bootstrap, AngularJS, Unity
Paradigms
Object-oriented Design (OOD), Design Patterns, REST, Unit Testing, Azure DevOps, Object-oriented Programming (OOP), Agile Software Development, Microservices, Scrum, RESTful Development, Dynamic Programming, Aspect-oriented Programming
Platforms
Oracle, Windows, Azure, Amazon Web Services (AWS), Amazon EC2, Linux
Storage
Microsoft SQL Server, Oracle PL/SQL, Azure Blobs, Azure Websites, Azure SQL, Azure Cache, Amazon S3 (AWS S3), MySQL, PL/SQL
Other
SQL Server 2015, Back-end Development, Machine Learning, Time Series Analysis, RESTful Microservices, Windows Communication Foundation (WCF), Web Services, SVMs, APIs, Intuit QuickBooks, Web Crawlers, OWIN, AWS Cloud Architecture
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