Elder Santos, Lead Developer in São José dos Campos - State of São Paulo, Brazil
Elder Santos

Lead Developer in São José dos Campos - State of São Paulo, Brazil

Member since March 13, 2013
An accomplished software engineer, Elder specializes in machine learning and data science. He has expertise in the full lifecycle of the software design process, including requirement specifications, prototyping, proof of concept, human-interface design, implementation, testing, and maintenance.
Elder is now available for hire


  • Joinesty, Inc.
    Amazon Web Services (AWS), Angular, React, Node.js, TypeScript, Python...
  • Toptal Clients
    Go, React, Node.js, TypeScript, Amazon Web Services (AWS), Elasticsearch...
  • LynasLogic
    Amazon Web Services (AWS), Oracle, Dapper, NHibernate, Entity Framework...



São José dos Campos - State of São Paulo, Brazil



Preferred Environment

GitHub, MacOS, Ubuntu, Windows, Visual Studio Code, Vi

The most amazing...

...project I've created was an aircraft maintenance program connected to the 1553 bus protocol. It uses enhanced shortest path algorithms and system optimizations.


  • Lead Software Engineer

    2016 - PRESENT
    Joinesty, Inc.
    • Created the whole cloud infrastructure and defined the stack for the back end and front end to support thousands of clients.
    • Managed the development team. Talked with stakeholders and investors about product road map and deliverables.
    • Designed and built a solution to store sensitive data from customers.
    Technologies: Amazon Web Services (AWS), Angular, React, Node.js, TypeScript, Python, .NET Core, Microsoft SQL Server, C#, Architecture, Front-end, Back-end, Azure, PostgreSQL, CTO
  • Software Developer

    2013 - 2021
    Toptal Clients
    • Designed and developed a web proxy filter in Go. The product was composed of a web proxy plus a web administration tool. Both components were written in Go.
    • Developed the filter according to the required RFCs and implemented the best security practices.
    • Contributed to gathering interest from big players in the data loss prevention industry.
    Technologies: Go, React, Node.js, TypeScript, Amazon Web Services (AWS), Elasticsearch, Docker, Bootstrap, jQuery, GraphQL, Python, Django, Flask, Next.js, C#, SQL, Software Architecture
  • Technical Lead

    2008 - 2016
    • Supported the software engineering team with technical decision-making.
    • Worked as a senior developer in the .NET platform.
    • Handled the development of applications related to financial products.
    • Maintained old and outdated C# projects for customers around the world.
    • Updated a legacy application using ASP.NET MVC, C#, JavaScript, MVVM, and Twitter Bootstrap, releasing an entirely new version.
    Technologies: Amazon Web Services (AWS), Oracle, Dapper, NHibernate, Entity Framework, MS Silverlight, Azure, JavaScript, Windows Communication Framework (WCF), Windows Presentation Foundation (WPF), PostgreSQL, PL/SQL, T-SQL, C#
  • Technical Lead

    2007 - 2008
    Microsoft Innovation Center
    • Handled technical requirements in interop projects.
    • Developed cross-platform software for Windows and Linux.
    • Worked with the most up-to-date Microsoft technologies, including Silverlight, WPF, WCF, and WWF.
    • Researched the local market and provided training for locals.
    • Supported local companies with technologies like Microsoft Silverlight, WPF, WCF, WWF, and SQL Server.
    Technologies: MS Silverlight, Windows Communication Framework (WCF), Windows Presentation Foundation (WPF), WWF, Java, Linux, Oracle, Microsoft SQL Server, SharePoint, VB.NET, C#, SQL Server BI, Software Architecture
  • Solution Archtect

    2007 - 2008
    Onset Technologies
    • Provided interoperability between .NET and Ruby applications.
    • Analyzed software requirements and provided solutions based on the Microsoft platform.
    • Solved business problems with solutions architected under the .NET platform and other Microsoft products.
    • Managed internal and external projects using Microsoft SharePoint technologies.
    • Created a global application for Johnson&Johnson to monitor all their other applications (including ERP) around the world.
    Technologies: SharePoint, C++, VB.NET, MySQL, Oracle, Microsoft SQL Server, C#, ASP.NET, ASP.NET MVC, jQuery


  • Sony Ci

    Sony's Ci Media Cloud expands into cloud-native asset management. With the addition of a catalog, Ci provides content owners, studios, production companies, broadcasters, sports leagues, music labels, and large corporations with a comprehensive system that supports content management.

  • SPL Fiscal

    A web application written in ASP.NET using NHibernate to handle ORM communication with SQL Server and Oracle databases. The app is used to generate digital files dynamically according to user configurations.

    It includes a great background execution process to analyze data and yield results in different formats.

  • Joinesty Password Manager

    A web-based and browser extension application to manage passwords and secret notes over different devices and share them with team workers. It is hosted on AWS and uses several services from that. The core back end is in Go and the front end is TypeScript with React.

  • Data Mining for Predictive Social Network Analysis (Publication)
    Analysts have come to recognize social network data as a virtual treasure trove of information for sensing public opinion trends and groundswells of support. In this article, Toptal Engineer Elder Santos describes the techniques he employed for a proof-of-concept that effectively analyzed Twitter Trend Topics to predict, as a sample test case, regional voting patterns in the 2014 Brazilian presidential election.


  • Languages

    Go, Python, SQL, JavaScript, C#, HTML, R, C++, HTML5, TypeScript, CSS, Visual Basic 6 (VB6), Less, T-SQL, VB.NET, Java, C, F#, Snowflake, GraphQL
  • Frameworks

    Flask, .NET, ASP.NET MVC, Windows Presentation Foundation (WPF), AngularJS, Django, Express.js, Entity, Windows Communication Framework (WCF), Bootstrap, NHibernate, ASP.NET Web API, ADO.NET, WWF, .NET Core, Angular, ASP.NET, Knockout (Knockout.js), Hadoop, Spark, AWS HA, Next.js
  • Libraries/APIs

    Node.js, jQuery, jQuery UI, Entity Framework, Vue, REST APIs, Facebook API, LinkedIn API, Twitter API, Backbone.js, React, Instagram API
  • Tools

    GitHub, Sublime Text, Microsoft Visual Studio, Amazon ECS (Amazon Elastic Container Service), Mercurial, TextMate, LINQ to SQL, Subversion (SVN), MS Silverlight, Dapper, Azure Kubernetes Service (AKS), Visual Studio, AWS Key Management Service (KMS), Webpack, Amazon SQS, AWS Push Notification Service (AWS SNS), Microsoft Project, Emacs, Microsoft Team Foundation Server, Amazon Athena, Jira, AWS CodeBuild, AWS Glue, DataViz, SQL Server BI
  • Paradigms

    Object-oriented Programming (OOP), Microservices, Agile Software Development, Functional Programming, Procedural Programming, Design Patterns, COM+, Distributed Computing, Parallel Computing, Microservices Architecture, Database Design, Web Architecture, API Architecture, REST, REST API Architecture, ETL, Requirements Analysis
  • Platforms

    Amazon Web Services (AWS), Windows, AWS Lambda, Linux, Oracle, Software Design Patterns, SharePoint, Azure Functions, Azure IaaS, Docker, Amazon EC2, AWS Kinesis, Ubuntu, Visual Studio Code, iOS, MacOS, Azure, Kubernetes
  • Storage

    MongoDB, Microsoft SQL Server, Relational Databases, JSON, NoSQL, PostgreSQL, Amazon S3 (AWS S3), PL/SQL, Redis, Elasticsearch, SQL Server 2012, Azure SQL, MySQL, SQLite, Redshift, Apache Hive, Data Lakes, AWS Data Pipeline Service, Databases
  • Other

    Machine Learning, Web Scraping, CTO, Technical Leadership, Data Engineering, Software Architecture, Software Design, COM, Crypto, Elastic Load Balancers, Leadership, ETL Tools, Full-stack, Integration, Fivetran, Data Analytics, Data Analysis, Data Warehousing, Big Data, Big Data Architecture, Amazon API Gateway, Data Reporting, Data, Data Warehouse Design, Code Architecture, Data Architecture, System Architecture, Requirements & Specifications, User Requirements, Architecture, Front-end, Back-end, Vi


  • Master Degree in Artificial Intelligence
    2014 - 2016
    Universidade Federal de São Paulo - Sao Jose dos Campos
  • Bachelor Degree in Computer Science
    2008 - 2012
    Universidade Federal de Sao Carlos - Sao Carlos, Brazil


  • Microsoft® Certified Technology Specialist
  • Microsoft Certified Dynamics Specialist
  • Microsoft Certified Application Developer
  • Microsoft Certified Systems Administrator:
  • Microsoft Certified Database Administrator
    JUNE 2003 - PRESENT
  • Microsoft Certified Solution Developer

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