Software Engineer

Hey 👋, I'm Rafał! I'm a software engineer passionate about building great products and solving challenging technical problems.

Recent Posts

• AWS Lambda, Azure Functions, and When to Reach for Step Functions Instead

  Posted on:May 13, 2026

  · 6 min read

  Lambda and Azure Functions are the easy part. Coordinating them — handling retries, state, error paths, timeouts — is where serverless gets hard. Step Functions solves that, but it's not always the right call.

  awsazureserverlessarchitecture

• Why Flutter Can't Easily Do Liquid Glass

  Posted on:May 13, 2026

  · 5 min read

  Apple's Liquid Glass isn't just a blur — it's a physically-based, real-time glass simulation that samples the entire render tree behind it. Flutter paints onto a single texture. Those two facts are incompatible.

  flutteriosrenderingui-design

• SQL-Style Triggers in NoSQL: DynamoDB Streams, CosmosDB Change Feed, and When Not to Bother

  Posted on:May 13, 2026

  · 5 min read

  NoSQL databases don't have triggers. But their event-driven primitives — streams, change feeds, CDC — let you build the same things with better decoupling. Here's how, and where it hurts.

  awsazurenosqlarchitecture

• LLM Token Context Windows and the Attention Architecture

  Posted on:May 9, 2026

  · 15 min read

  A deep dive into how LLMs manage context through attention mechanisms, and the engineering tricks that push context windows past their quadratic limits.

  llmtransformersattention

• SwiftUI Under the Hood: Its Architecture and Relationship to UIKit

  Posted on:May 8, 2026

  · 10 min read

  SwiftUI is not a black box replacement for UIKit. It's a view graph diffing engine that runs on top of UIKit and AppKit. Here's how it actually works.

  swiftuiiosuikit

• Understanding Copy-on-Write in Swift

  Posted on:May 7, 2026

  · 5 min read

  Swift's value types avoid expensive copies until you actually mutate them. Here's how CoW works under the hood.

  swiftios

• How Does an LLM Know It's Done?

  Posted on:May 6, 2026

  · 4 min read

  LLMs don't 'feel' done. They stop because the math tells them to. Here's how.

  llm

• Best Practices for Unit Testing iOS Apps

  Posted on:October 20, 2022

  · 2 min read

  Tests are automated. Run often. Preferably on each commit or pull request to quickly catch regressions.

  ios

• Reference Cycles in iOS

  Posted on:September 20, 2022

  · 1 min read

  Strong reference cycles prevent instances from ever being deallocated, causing a memory leak.

  ios

• Concurrency and Parallelism in iOS

  Posted on:September 19, 2022

  · 1 min read

  iOS offers several ways to run tasks concurrently. This article is a short summary of them.

  ios