So you want to optimize your code, eh? Who am I to blame you? I certainly want you to optimize your code! I spent a few years as part of the Firefox Performance Team, on the frontline of, well, performance. I still bear some of the scars. So, as the grizzled perf-veteran that I have decided to be for the day, let me invite you to sit down for a while and share a little hard-earned experience on code optimization.

I’ve been a programmer since the age of 8, and some kind of developer for most of my life. Throughout my life as a coder, both hobbyist and professional, I’ve learnt plenty of programming languages that felt like cookie-cutter clones of each other, but also a few programming languages that changed the way I looked at programming, sometimes even at thinking.

(This is meant to be the first entry of a series which will cover individual points more in depth. We’ll see how that goes.) We’re the tech industry. We have ideas. We have ideas all the time. And we’re used to turn our ideas into applications. So, how does it go… here’s the back-end component… here’s the front-end component. We’ll write the former in Python, or perhaps JavaScript, to optimize for prototyping. After all, we have so many ideas, we need the ability to iterate quickly. Sprinkle in a few dependencies, that will speed us up. Oh, and let’s use ChatGPT and Copilot, we’ll be even faster. Oh, and performance, yeah, performance: microservices, Kafka, Redis, Kubernetes… we’re now ready to scale up. Oh, Sentry, Prometheus and Grafana, too, where would we be without ’em? For the front-end, we’ll write a website, and for mobile, Electron. Oh, wait a second, we need to make money and to fidelize our users! Let me see… ads, tracking, and good reasons to revisit our app, perhaps a little NFT here, gamification… alright, we should be good. Three… two… one… and we have shipped v1! Also, the world is burning. Perhaps it’s time we revisited how we do things?

Recent publications by Consumer Reports and the NSA have launched countless conversations in development circles about safety and its benefits. In these conversations, I’ve seen many misunderstandings about what safety means in programming and how programming languages can implement, help or hinder safety. Let’s clarify a few things.

A number of programming languages offer a feature called “Named Arguments” or “Labeled Arguments”, which makes some function calls much more readable and safer. Let’s see how hard it would be to add these in Rust.

A long time ago, the Rust language was a language with typestate. Officially, typestates were dropped long before Rust 1.0. In this entry, I’ll get you in on the worst kept secret of the Rust community: Rust still has typestates.