Jonathan Feller
Verified Expert in Engineering
Full-stack Developer
Blumenau - State of Santa Catarina, Brazil
Toptal member since March 12, 2021
Jonathan is a passionate developer with 9+ years of experience, having worked with many technologies and teams of various sizes, from startups to big corporations. He started programming at a very early age and has been doing it ever since, always looking for exciting challenges to work on. Jonathan brings strategic vision and leadership to his work and is passionate about working with teams whose vision aligns with his values.
Portfolio
Experience
Availability
Preferred Environment
React, Node.js, PostgreSQL, JavaScript, TypeScript, ECMAScript (ES6), Git, Visual Studio Code (VS Code), REST, GraphQL
The most amazing...
...thing I've ever done is lead the development of a corporate tax revenue module as a service for the whole company to use.
Work Experience
Full-stack Engineer
Gunar LTD
- Led the discovery phase for multiple projects, talked to clients, and defined product requirements and proposals.
- Architected and developed several applications from scratch.
- Trained and led junior developers onboarding the team.
Full-stack Developer
Mout'S Solues em TI
- Tasked with the full-stack development of several web platforms and apps from scratch.
- Refactored existing APIs to follow RESTful best practices.
- Developed an app in a week to track COVID-19 symptoms.
- Improved legacy code quality with refactors and clean code principles.
Software Engineer
Senior Sistemas
- Built and maintained an integration and migration tool between the legacy monolithic database and a new cloud distributed database.
- Migrated business logic and features from legacy software to the new cloud-based ERP.
- Led the development of a tax engine as a service, maintaining constrained response times with multi-million parameters.
C++ Software Developer
WK Sistemas
- Developed from scratch and maintained the new Corporate Tax Module, rewriting code based on the legacy Delphi version.
- Built the tax calculation procedure, bringing down the time from two minutes to three seconds.
- Wrote a migration tool to move data from the legacy software to the new one.
- Integrated the Corporate Tax Module with other modules.
Software Developer
GOVERNANÇABRASIL S/A Tecnologia e Gestão em Serviços
- Developed new features for the accounting module aimed at more efficient use of the software.
- Tracked and fixed bugs using Mantis as a reporting tool.
- Created and worked on several internal tools to allow developers to work more efficiently.
Experience
Talent Panel
jfGL - An Independent Graphics Library
I implemented vector and quaternion operations and matrix transformations.
Applied Gouraud shading and Phong shading with point and directional lighting.
Implemented scan-line rendering algorithm with back-face culling, z-buffering, and frustum clipping.
Every pixel is rendered in software; there is also a 3D editor and texture mapper developed on top of it.
Scribble
This project was fun to develop and quite simple in its essence, heavily focused on real-time data communications and network optimizations, simple UI with a real-time chat for people to guess the word and interact.
Skills
Libraries/APIs
React, Node.js, Microsoft Foundation Class (MFC) Library, Socket.IO, Microsoft Foundation Classes (MFC)
Tools
Git, Visual Studio 2015, Subversion (SVN), TFS, Mantis, Jira, RabbitMQ
Languages
JavaScript, ECMAScript (ES6), Visual Basic 6 (VB6), C, CSS, HTML, TypeScript, Visual Basic, C++, Java, SQL, GraphQL, C#
Frameworks
Angular, Next.js, Spring Boot, Hibernate, Express.js
Platforms
Docker, Visual Studio Code (VS Code), Visual Studio 2017, Azure, AWS Lambda, Amazon Web Services (AWS), Firebase
Paradigms
REST, Microservices, Scrum, Kanban
Storage
PostgreSQL, MySQL, Google Cloud, Redis, SQL Server 2008 R2, SQL Server 2012, Elasticsearch, InfluxDB, MongoDB, Hasura, Amazon DynamoDB
Other
Full-stack, 3D Graphics, Mathematics, Infrastructure Architecture, APIs, Architecture, COM, DCOM, Serverless
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