Sunday Swift

Hi. I'm Hesham. I'm a software engineer, motorcyclist, dog lover, coffee enjoyer, and guitarist. I'm currently building at Notion .

Previously, I built GitHub Mobile , which came to the world via GitHawk , which I collaborated on. Before that, I spent some time working at GameChanger , a youth sports platform, and at VTS , a platform for commercial real estate.

I find myself with a lot of fleeting thoughts about code, developer ergonomics, and occasionally writing entire *complete* applications that I end up scrapping for no particular reason. I decided to start sharing these snippets as I go about creating them instead of running through the exercises of making them and tossing them.

Featured

• Building Lists: A High-Performance Diffable Data Source Framework

  Posted on:February 14, 2026

  A deep dive into the design, performance, and trade-offs behind Lists — a pure-Swift replacement for UICollectionViewDiffableDataSource that's up to 1000x faster than Apple's implementation.

• Generating `Hashable` and `Equatable` for functions

  Posted on:April 4, 2023

  Often, we pass functions as stored arguments to an object. In this quick tip, we explore how we can still maintain `Hashable` and `Equatable` when we do so, without having to write it ourselves.

• Using Cross Import Overlays to Improve Your Libraries

  Posted on:March 19, 2023

  How to use cross import overlays in your project, today

Recent Posts

• Building Lists: A High-Performance Diffable Data Source Framework

  Posted on:February 14, 2026

  A deep dive into the design, performance, and trade-offs behind Lists — a pure-Swift replacement for UICollectionViewDiffableDataSource that's up to 1000x faster than Apple's implementation.

• Building a Multi-Agent Code Reviewer

  Posted on:February 13, 2026

  What I learned building claude-deep-review, a code review skill that decomposes review into 15 specialized agents running in parallel.

• Orchestrating AI Agents with Claudio: Lessons from Parallelizing Claude Code

  Posted on:February 13, 2026

  What I learned building Claudio, a tool that runs multiple AI coding agents simultaneously using git worktrees

• Shipping a CLI on FoundationModels

  Posted on:February 13, 2026

  What it's actually like to build a real tool on Apple's on-device FoundationModels framework — the 4,096 token ceiling, blind token budgeting, and everything in between