Leonardo Kewitz
Senior Software Engineer at Open Finance Consortium
Madrid, Community of Madrid, Spain
Summary
🤩
Rockstar🎓
Top SchoolLeonardo Kewitz is a Senior Software Engineer based in Madrid with 12 years of experience building readable, elegant solutions across front-end and back-end stacks. He advocates for code as human expression, favoring simplicity and clarity while shipping production systems that span React/Next.js front ends and GraphQL/Postgres back ends. At Open Collective he improved core systems—implementing Redis/Memcache cache providers and hardening payment integrations like PayPal and Stripe—demonstrating both infrastructure and product-level impact on a well-known open-source platform. His background includes low-level GPU research and C/C++/CUDA work as well as full-stack JavaScript and C# enterprise tooling, giving him a rare blend of systems, performance, and UX sensibilities. Currently at Open Finance Consortium, he continues to bridge API, caching, and UX concerns with pragmatic engineering and a penchant for thoughtful refactors. An avid contributor, his GitHub motto “Cache rules everything around me” reflects a practical obsession with performance and reliability that drives many of his contributions.
12 years of coding experience
11 years of employment as a software developer
Data Science Bootcamp, Data Science Bootcamp at Le WagonMaster of Engineering, Electrical Engineering, Master of Engineering, Electrical Engineering at Universidade Regional de Blumenau
Portuguese, English
Github Skills (18)
caching10
javascript10
postgresql10
back-end-development10
user-interface10
nextjs10
nodejs10
react10
validations9
redis9
validation9
css9
html9
graphql8
cost-management8
Programming languages (7)
Github contributions (5)
opencollective/opencollective-frontend
Feb 2019 - Jan 2023
Open Collective's Frontend. A React app powered by Next.js.
Role in this project:
Front-end Developer
Front-end DeveloperContributions:395 reviews, 832 commits, 1064 PRs in 4 years
Contributions summary:Leonardo primarily focused on improving the front-end of the Open Collective platform, by implementing and refactoring React components. They fixed UX problems and addressed issues with validation and data handling in the contribution flow, the profile pages and expense management. The user's work also involved updates to the styling and display of various components within the application.
next-jsreactfrontendopencollectivewebpack
opencollective/opencollective-api
Feb 2019 - Jan 2023
Open Collective's API. A GraphQL API powered by Sequelize and PostgreSQL.
Role in this project:Backend Developer
Backend DeveloperContributions:628 reviews, 1017 commits, 1422 PRs in 4 years
Contributions summary:Leonardo contributed to the Open Collective API project, focusing on backend development. Their work involved implementing cache providers, including Redis and Memcache, as well as refactoring existing caching mechanisms. They also contributed to the payment providers' code base, making the PayPal requests host-dynamic and making modifications to the Stripe credit card and transferwise.
apigraphql-apisequelizeapi-snodejs
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