Kewin Wereszczyński

Kewin Wereszczyński

Software Engineer

Started his career as a tester before transitioning into programming, working on numerous startup projects as a solo frontend developer or in small teams. His biggest achievement was becoming a frontend lead on one of the projects. Passionate about 3D graphics, games, special effects, photography, and cinematography, he has also explored being a rock band vocalist, English stand-up performer, improviser, and YouTuber. Recently, he has become a bit obsessed with AI.

What I’ve been shipping

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Performant and Cross-Platform Shimmers in React Native Apps

A modern shimmer library for React Native with smooth UI skeletons, minimal dependencies, and optimized performance using Reanimated and SVG. Drop-in ready with full customization and shared animation state.

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How I Used MCP to Control My Friend's Home

Learn how MCP works with a hands-on project that connects Claude AI to smart home data using a Node.js server.

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Want to Run LLMs on Your Device? Meet MLC

Find out how MLC compiles both model and runtime for efficient local LLM inference, and what that means for running AI on your Android or iOS app.

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Local LLMs on Mobile Are a Gimmick-For Now

Can local LLMs replace cloud-based AI? We analyze performance, limitations, and the future of on-device AI models in 2025.

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Giving AI The Keys to Your App: Agents Controlling UI State

Learn how to let AI agents control UI state in React using Jotai and Flows-AI, automating logic and workflows for smarter, autonomous applications.

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Building AI Agent Workflows With Vercel’s AI SDK: A Practical Guide

Learn to build AI Agent workflows with Vercel's AI SDK. Explore chaining, routing, parallel & evaluator-optimizer patterns.

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Creating a Video Transcription App: Lessons Learned

Read about Callstack's R&D journey into AI for a transcription app, using OpenAI's Whisper for speech recognition. Discover the lessons learned.

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Building a Custom AI Assistant for Your Business

Learn what it takes to build a custom AI-powered chatbot for your company, including the challenges, solutions, performance, and security considerations.

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Live Dev Session: Week 37 React & React Native Rundown

Join Callstack’s Łukasz & Kewin for a live React recap: fresh news, vibey code sessions, and good dev talk. Happening Thursday, September 11, 5PM CEST.

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Live Dev Session: Routers, React Native AI, and Expo Launch

Nuqs 2.5, Remix v3, Expo Launch, SPM support in React Native, the Jest RFC, and native Text-to-Speech with guest insights from Mike Grabowski.

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Live Dev Session: Expo SDK 54 Beta Is Here, Next.js 15.5, RNEF Renamed Rock

Explore what's new in Expo SDK 54 Beta: Liquid Glass, faster iOS builds, RN 0.81, and more dev upgrades from this week's livestream.

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Live Dev Session: FlashList v2, Vercel AI SDK, React Compiler

This week's livestream highlighted two major releases reshaping the React and React Native landscape: FlashList v2 and Vercel AI SDK 5.

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Live Dev Session: Rozenite DevTools Plugins Framework, Precompiled React Native for iOS, TanStack DB 0.1

Discover Rozenite: DevTools framework for React Native, faster iOS builds, on-device AI, and key updates from this week’s livestream.

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Live Dev Session: Reanimated 4, Worklets, React Native Screens

This week was packed with insights on highly anticipated Reanimated 4, the power of Worklets, Screens and more.

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Live Dev Session: Node-API, Wallets & Worklets in React Native

Node-API in RN, Apple’s LLM, react-native-wallet, ChromeOS rumors. The Week 29 React Native stream breaks it all down with some code and a lot of commentary.

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Live Dev Session: Unistyles 3.0, SSR With Hermes & Expo SDK 52

From inside shadows to decentralized music players, catch the latest React Native takes in Week 28 live dev session with Łukasz, Kewin, and Mike.

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Live Dev Session: Exploring Skia, Nitro Modules & UI Playgrounds

Live dev stream exploring Skia, Nitro Modules, AI app builders, and React Native tools; plus side quests into canvas UIs, Lottie, and pizza-coded joy.

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Live Dev Session: React Native Styling, OTA, and UI Tools

Tune in to a live session unpacking React Native 0.80, OTA alternatives, AI-generated UIs, styling wars, and some truly wild tech tangents.

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Live Dev Session: First Impressions of Apple’s On-Device AI

Tune in to dev chat on Apple’s AI SDK, iOS 26 naming chaos, Siri’s limits, Liquid Glass UI, and on-device LLMs.

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Run LLMs Locally With React Native & MLC

Watch how MLC brings on-device AI to React Native. See react-native-ai in action and discover what’s next for local model execution.

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