Karolis Masiulis
Graphics Engineer at Flowstep
Vilnius, Vilnius County, Lithuania
Summary
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RockstarKarolis Masiulis is a Graphics Engineer and founding staff technologist with 11 years of experience building performant web applications and visual tooling from Vilnius, Lithuania. He currently leads development of Flowstep’s editor, focusing on WebGL/WebGPU rendering, a proxy-based state manager, and reliability for complex interactive workflows. Previously he architected end-to-end systems at Riddle and Fresha—introducing GraphQL gateways, improving developer experience, and implementing data reconciliation with DuckDB and Postgres. As a co-founder of Ugnis he shipped a React-based spreadsheet import tool that automates column matching and validation, demonstrating a knack for practical UX in data-heavy interfaces. Karolis blends deep frontend skills (React, TypeScript, WebGPU) with backend and data engineering experience, often improving build and deployment flows to speed delivery. He’s drawn to visual programming and editor infrastructure, combining startup instinct with production-grade engineering discipline.
11 years of coding experience
9 years of employment as a software developer
Github Skills (13)
uid10
typescript10
javascript10
typescripts10
front-end-development10
ui-design10
react10
typescript-types10
chakra-ui10
data-validation9
excel9
csv9
xlsx9
Programming languages (3)
Github contributions (5)
UgnisSoftware/react-spreadsheet-import
Jan 2022 - Sep 2022
Import flow for Excel (.xlsx) and CSV file with automated column matching and validation.
Role in this project:
Front-end Developer
Front-end DeveloperContributions:19 reviews, 244 commits, 59 PRs in 7 months
Contributions summary:Karolis primarily contributed to the front-end development of the React spreadsheet import project. Their commits focused on building UI components such as a table, input, select, and checkbox components, and integrating them with the React-Data-Grid library. The user also implemented features to allow selecting rows within the table, along with the addition of data validation rules. Furthermore, the user introduced styling and theming with chakra-ui library and incorporated tooltips for displaying error messages.
xlsxcsvreactimport-flowxls
UgnisSoftware/lape
Aug 2017 - May 2022
State manager for React
Contributions:125 commits, 11 PRs, 116 pushes in 4 years 9 months
reactstate-managementreact-hooksreduxhooks
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