Swift Tips That Actually Make You Faster in 2026
The fastest Swift wins come from letting the compiler catch mistakes. Model states with enums and associated values, default to structs, and use async/await over completion handlers. Fewer runtime crashes, less debugging, and code that reads clearly six months later. That is what actually saves time.
Part of the complete app development guide.
On this page
- Stop guessing: let the compiler do the work
- Use enums with associated values instead of flag soup
- Prefer value types until you can’t
- async/await is the default now, so use it properly
- Mark your UI code @MainActor
- Macros changed how I write boilerplate
- Turn on the compiler checks you’re skipping
- Small things that add up
- FAQ
- Do I need to rewrite my whole app to use async/await?
- Are Swift macros safe to use in production?
- Is strict concurrency checking worth the initial pain?
Most “Swift tricks” posts are just lists of syntax nobody uses in a real app. I write production Swift for iOS and server-side work, and these are the habits that have actually cut time off my builds and bugs off my releases. Nothing here requires a framework or a paid course.
Stop guessing: let the compiler do the work
Swift’s type system is the single biggest time saver you have, and most people only use a fraction of it. A few changes to how you model data pay off for the life of the project.
Use enums with associated values instead of flag soup
If you have a struct with an optional field that’s only valid in certain states, you have a bug waiting to happen. Model the states directly.
enum LoadState<T> {
case idle
case loading
case loaded(T)
case failed(Error)
}
// Now the compiler forces you to handle every case.
switch state {
case .idle:
showPlaceholder()
case .loading:
showSpinner()
case .loaded(let items):
render(items)
case .failed(let error):
showError(error)
}
You cannot accidentally read items while the request is still in flight, because there is no items until there is a .loaded. That’s an entire class of crash removed at compile time.
Prefer value types until you can’t
Structs are copied, which sounds expensive and usually isn’t. Swift’s copy-on-write for collections means you rarely pay for the copy until you mutate. Default to struct. Reach for class when you genuinely need shared mutable identity or reference semantics, like a cache or a delegate.
async/await is the default now, so use it properly
If you’re still chaining completion handlers in 2026, you’re writing more code than you need to. The part people get wrong is structured concurrency: they spawn tasks and forget who owns them.
func loadProfile(id: User.ID) async throws -> Profile {
async let profile = api.profile(id)
async let posts = api.posts(for: id)
// Both requests run concurrently. You await once.
return try await Profile(user: profile, posts: posts)
}
Two network calls, one round trip worth of wall time. That’s the win. The trap is Task { } sprinkled everywhere, which breaks cancellation and makes errors hard to trace. Keep tasks tied to a view or a parent task so cancellation propagates when the user navigates away.
Mark your UI code @MainActor
Chasing “Publishing changes from background threads” warnings is a waste of an afternoon. Annotate the type that touches UI, not every method, and the compiler enforces it for you.
@MainActor
final class ProfileViewModel: ObservableObject {
@Published private(set) var state: LoadState<Profile> = .idle
func load() async {
state = .loading
do {
state = .loaded(try await api.profile(id))
} catch {
state = .failed(error)
}
}
}
Macros changed how I write boilerplate
Swift macros are mature enough that I lean on them for the boring stuff. @Observable replaced a pile of @Published properties. #Preview cut my preview code down to a few lines. If you’re still hand-writing Codable conformance for anything non-trivial, check whether a macro already does it.
One caution: macros are code generation, and generated code still has to be debugged. Don’t pull in a macro library you don’t understand to save ten lines.
Turn on the compiler checks you’re skipping
This is the least glamorous tip and the one that saves the most time. In your build settings:
- Strict concurrency checking set to complete. Yes, it’s noisy at first. It’s also the difference between a data race in production and a red squiggle in Xcode.
- Treat warnings as errors for your own targets. Warnings accumulate until nobody reads them.
- Upcoming feature flags enabled where you can. You get the next language mode’s behavior early and find breakage on your schedule, not Apple’s.
Small things that add up
- Use
guardfor early exits. Nestedif letpyramids are where logic bugs hide. - Reach for
someandanydeliberately.somekeeps the concrete type and performance;anyboxes it. Know which one you’re asking for. - Profile before you optimize. Instruments will tell you where the time actually goes, and it’s almost never the line you suspected.
- Keep types small. A 900-line view controller is a debugging tax you pay forever.
None of this is exotic. It’s the difference between fighting the language and letting it catch your mistakes. If you’re building an app and want someone who writes Swift this way handling the front end and the backend around it, that’s the kind of custom web development and mobile work I do from Commack.
FAQ
Do I need to rewrite my whole app to use async/await?
No. Wrap one call site at a time. Bridge old completion-handler APIs with withCheckedContinuation and migrate the pieces that give you the most pain first.
Are Swift macros safe to use in production?
Yes, if you understand what they generate. Expand the macro in Xcode and read the output before you trust it in a shipping build.
Is strict concurrency checking worth the initial pain?
For anything that ships, yes. It surfaces real races at compile time instead of in crash reports, and the noise drops fast once your types are properly isolated.
