Guilherme Stiebler, Developer in Vancouver, BC, Canada
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Guilherme Stiebler

Verified Expert  in Engineering

Software Developer

Vancouver, BC, Canada
Toptal Member Since
December 12, 2016

Guilherme is an experienced software engineer from AWS specializing in scalable technical solutions and back-end development. He has a proven track record in optimizing complex systems and is an expert in AI, Java, TypeScript, and Python. Guilherme is passionate about driving project success with innovative, efficient tech solutions.


Amazon Web Services (AWS)
Java, TypeScript, Ruby, Python, Amazon DynamoDB, AWS IAM, Distributed Software...
PayerSciences LLC
Node.js, JavaScript, React, Amazon Web Services (AWS), GraphQL, Docker Compose...
Performitiv, LLC
Docker, Elasticsearch, ECMAScript (ES6), JavaScript, MongoDB, Node.js, Vuex, Vue




Preferred Environment

MacOS, Visual Studio Code (VS Code)

The most amazing...

...things I've created were the plate location and character segmentation algorithms for an automatic license plate recognition system.

Work Experience

Software Development Engineer

2021 - 2023
Amazon Web Services (AWS)
  • Developed new features for a new AI-based AWS service yet to be launched.
  • Contributed to the conversion of an in-memory database to a custom MVCC database for AWS Honeycode.
  • Led the design and implementation of an optimization to real-time updates to views of a graph-based database, leading to 40x fewer queries.
Technologies: Java, TypeScript, Ruby, Python, Amazon DynamoDB, AWS IAM, Distributed Software, Artificial Intelligence (AI), GraphQL

Full-stack Developer

2020 - 2021
PayerSciences LLC
  • Handled the development of the account management planner (AMP).
  • Implemented end-to-end features, including the infrastructure, back end, front end, and automated tests.
  • Improved productivity by simplifying the React code.
Technologies: Node.js, JavaScript, React, Amazon Web Services (AWS), GraphQL, Docker Compose, Docker, Azure DevOps, Continuous Delivery (CD), Continuous Integration (CI), Kubernetes, Azure, Git, Microservices, Agile Software Development, API Architecture, Web Architecture, CSS, Progressive Web Applications (PWA), PostgreSQL

Software Developer

2017 - 2020
Performitiv, LLC
  • Implemented global search using Elasticsearch, improving user experience.
  • Promoted software development best practices and the adoption of ES6 features.
  • Optimized MongoDB queries—one of the best results was that the generation time of a report dropped from 25 seconds to 5 seconds.
  • Rewrote parts of the system from AngularJS to Vue/Vuex.
Technologies: Docker, Elasticsearch, ECMAScript (ES6), JavaScript, MongoDB, Node.js, Vuex, Vue

Software Developer

2017 - 2017
Delmic (via Toptal)
  • Implemented the reading of tiled images and sub-images from TIFF files on PyLibtiff.
  • Implemented on-demand loading of large TIFF files on Odemis, a software for visualizing microscope images.
  • Implemented a plugin for Odemis to align microscope images from different sources using OpenCV matching algorithms.
  • Implemented automated tests for all developed features.
Technologies: Linux, OpenCV, C, NumPy, Python

Software Developer

2009 - 2016
  • Led the architecture design of a finite element method physics simulator.
  • Contributed to a 3D seismic visualizer using OpenGL and C++.
  • Led the group that implemented automatic testing, tool selection, and process determination.
  • Developed on-demand loading of large seismic files. The startup of the software after loading a large file changed from several minutes to seconds.
  • Led the adoption of an object-oriented approach for the development of common GUI elements in the system.
  • Developed an algorithm for riser interference detection with complexity of O(n log n + m log m). The previous algorithm had O(n2 + m2) complexity.
  • Analyzed a poorly documented and engineered 25-year-old FORTRAN code and converted it to a well-structured, object-oriented C++ code.
Technologies: Linux, CMake, Git, Boost, Eclipse, Visual Studio, Qt, OpenGL, C++

Founder and Software Developer

2007 - 2008
Quasar Group
  • Created and developed the Cableway software. It reads CAD files, processes them, and shows several reports.
  • Implemented an OpenGL 2D viewer for CAD files.
  • Designed the cable route code based on the Djikstra algorithm for the Cableway software.
  • Developed the integration with a CAD reading library.
  • Managed the development of an ERP based on Ruby on Rails and Adobe Flex.
Technologies: MySQL, Adobe Flex, Ruby on Rails (RoR), Ruby, OpenGL, C++

Co-founder and R&D Manager

2006 - 2006
  • Improved the computer vision algorithms of the Kapta software for automatic license plate recognition.
  • Managed a team of developers for the implementation of computer vision algorithms and a desktop application that used the algorithms.
  • Worked on multithreaded code that managed the different phases of the computer vision processes.
  • Worked on the object-oriented redesign of the Kapta software.
  • Worked on fundraising activities to support the growth of the company.
Technologies: Machine Learning, Computer Vision, C++

Software Developer

2002 - 2005
LABIC UFRJ - Computational Intelligence Lab
  • Developed the plate location algorithm for Kapta, a software for automatic license plate recognition using computer vision. The newly created algorithm had a accuracy of 94%. The previously used algorithm had a accuracy of 76%.
  • Developed a variation of the Watershed algorithm for character segmentation.
  • Developed a custom memory manager that used the systems pattern of memory allocation to avoid calling OS memory allocation and deallocation.
  • Published the paper: "KAPTA - A system for automatic plate recognition based on the technics of neural networks and image processing" in SUCESU 2004. This paper was awarded as the best paper of the event.
  • Worked on the features extraction of the characters for the input of the neural networks.
Technologies: Machine Learning, Computer Vision, C++

Software Developer

1999 - 2001
Segredo Constructions, LLC
  • Developed an ERP for a small-sized construction company.
Technologies: InterBase, Delphi

Pura Cozinha
A marketplace to connect customers with people cooking from home.

Insider Oil
A business intelligence platform for the Brazillian oil industry.


Desktop software for electrical projects on ships and oil platforms. It reads and processes AutoCAD and Microstation files and generates several kinds of reports.

Tio Patinhas
A mobile application for blind people to recognize paper money. It takes a picture of a bill and reads its value out loud. There were two versions: a Windows Mobile 6.0 version, and a J2ME version.

Software for visualizing the dataflow of information of C++ source code.

A small Python program to optimize the use of cable disposition in cable trays. It uses a genetic algorithm to solve the underlying knapsack problem.

Image Compression Algorithm Implementation

An image compression algorithm implemented in C++ for a Master's degree capstone project for Milton Simas Torres at the Instituto Militar de Engenharia - IME.

Vision Workbench
A Qt application interface to experiment with OpenCV algorithms
2001 - 2009

Bachelor's Degree in Computer Science

UFRJ - Rio de Janeiro, Brazil


Node.js, React, Standard Template Library (STL), OpenCV, Google Maps, Google Chart API, NumPy, MobX, OpenGL, Vue, Vuex


Microsoft Visual Studio, Git, Visual Studio, CMake, Webpack, MATLAB, Docker Compose, AWS IAM


Express.js, React Native, Boost, Ruby on Rails (RoR), Adobe Flex, Material UI, Redux, AngularJS, Qt, Flutter


Object-oriented Programming (OOP), Agile Software Development, Scrum, Functional Programming, Continuous Delivery (CD), Azure DevOps, Continuous Integration (CI), Microservices, API Architecture, Web Architecture


C, ECMAScript (ES6), TypeScript, JavaScript, C++, SQL, Python, Java, Kotlin, HTML, Ruby, C#, GraphQL, Delphi, Flash ActionScript, Assembly, Pascal, CSS, Dart


Visual Studio Code (VS Code), Linux, Docker, MacOS, Eclipse, AWS Lambda, Amazon Web Services (AWS), Amazon EC2, AWS Elastic Beanstalk, Firebase, Kubernetes, Azure


MongoDB, MySQL, InterBase, Elasticsearch, Amazon S3 (AWS S3), PostgreSQL, Amazon DynamoDB, Cloud Firestore


Algorithms, Multithreading, Data Structures, Computer Vision, Machine Learning, Mathematical Modeling, Serverless, SDKs, Software, Progressive Web Applications (PWA), Distributed Software, Artificial Intelligence (AI), OpenAI GPT-4 API

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