April 18, 2026

Training an LLM in Swift, Part 1: Taking matrix multiplication from Gflop/s to Tflop/s

10 implementations of handwritten matrix multiplication: from plain C and Swift through to Metal

In this article, I try to get my own handwritten matrix multiplication code running as fast as possible for training a Large Language Model (LLM) in Swift. The aim is to give some insight into the key steps for optimizing mathematics code in Swift. I also hope that these examples will offer a sense of scale about the capabilities of the different units on …

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Dec 29, 2025

Have LLMs improved for Swift coding in the last 12 months?

A small followup, 12 months after the previous article, looking at the improvements in different LLMs for Swift development

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Dec 25, 2024

Using Copilot to write a raindrop audio synthesizer using AVAudioEngine

A quick look at the state of LLM assistants for Swift programming but also having fun with AVAudioEngine and SwiftUI Charts

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Mar 23, 2021

App architecture basics in SwiftUI Part 4: Services

This article is about adding a separated Services-layer to an app. A Services-layer is, in my opinion, the single best app architectural addition you can make, after the basic Model-View separation already implicit in SwiftUI.

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Feb 12, 2021

App architecture basics in SwiftUI Part 3: Module-separated layers

Slicing an app into modules is the best organizational step you can make. It's a step you should take before you choose to make any other deliberate architectural choice.

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Jan 19, 2021

App architecture basics in SwiftUI, Part 2: SwiftUI's natural pattern

I'll look at the pattern that application architectural pattern that emerges naturally when writing SwiftUI apps in a minimalist way. I'll also look at the different roles that exist in the basic SwiftUI application architecture.

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Dec 31, 2020

App architecture basics in SwiftUI, Part 1: Coding through iteration and integration

I'm going to write a JSON feed reader app in SwiftUI and focus on writing the app through small, incremental additions.

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Aug 18, 2019

22 short tests of combine – Part 3: Asynchrony

This article will be the final third of my investigation, looking at sequencing and threading in Combine; what guarantees does Combine offer for thread safety and delivery order. I'll finish up with a quick look at Combine's performance.

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Aug 17, 2019

22 short tests of combine – Part 2: Sharing

This middle third of the investigation will span a trio of topics: sharing computation, shared reference lifetimes and sharing subscribers.

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Aug 16, 2019

22 short tests of Combine – Part 1: Protocols

This article will be the first third of my investigation into Combine, covering an effort to re-implement the three key protocols of Combine: `Publisher`, `Subscriber` and `Subscription`

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