Swift Engineering, Including the Migrations Nobody Wants to Start
Swift and SwiftUI development for new Apple platform products, plus the less glamorous work: moving Objective-C codebases forward, adopting Swift concurrency, and getting old apps onto supported foundations.
What is Swift used for and when do you need Swift developers?
Swift is Apple's programming language for iOS, iPadOS, macOS, watchOS, tvOS and visionOS applications, and it is the language Apple's current frameworks and tooling are designed around. You need Swift developers to build native Apple platform apps, to migrate an existing Objective-C codebase onto a maintainable footing, or to adopt Swift concurrency and SwiftUI in an app that has fallen behind. Anviam provides Swift engineers for new builds, migrations and embedded team roles.
- Swift version
- Swift 6 with strict concurrency
- UI frameworks
- SwiftUI and UIKit, mixed as needed
- Platforms
- iOS, iPadOS, macOS, watchOS, visionOS
- Migration approach
- Incremental, module by module
- Testing
- XCTest, XCUITest, snapshot tests
- Engagement
- Project build or embedded Swift engineers
The Objective-C App Still Making Money Is the Hard Problem
Greenfield Swift work is straightforward. The genuinely difficult engagements are the apps written in Objective-C years ago that still serve real users and real revenue, where nobody wants to touch them because the original team has gone and the test coverage is thin. Leaving them alone is also not free: each iOS release raises the risk, hiring for Objective-C gets harder, and eventually a deprecation forces the issue on someone else's schedule.
We handle these incrementally, because Swift and Objective-C interoperate well enough to make that practical. Get characterisation tests around the current behaviour first. Add new features in Swift. Convert existing modules when they need changing anyway, starting with the ones that change most often. Each step ships independently, so the app keeps earning throughout and the work can pause without leaving a half-finished rewrite behind.
Swift Development Services
New Swift & SwiftUI Apps
Native Apple platform applications built in modern Swift with structured concurrency from the start.
Objective-C to Swift Migration
Incremental, test-backed migration that ships in stages rather than a risky all-at-once rewrite.
Swift Concurrency Adoption
Moving completion handlers and GCD onto async/await and actors, resolving data-race warnings properly.
UIKit to SwiftUI Transition
Screen-by-screen SwiftUI adoption inside existing UIKit apps, without a full-app commitment.
Swift Packages & Shared Modules
Reusable Swift packages for teams running several apps that need shared logic and design components.
macOS & Multiplatform Apps
Mac applications and code shared across iOS, iPadOS and macOS where a single team maintains all three.
Swift Tooling and Frameworks We Use
What Clients Bring Us Swift Work For
Unsupported Legacy App
An Objective-C app on old dependencies that a coming iOS release is likely to break.
Lost Institutional Knowledge
The developer who wrote it has left and nobody remaining can safely change it.
Concurrency Crashes
Intermittent, hard-to-reproduce crashes from threading bugs that Swift 6 concurrency checking exposes.
Slow Feature Delivery
A codebase where every change takes weeks because architecture and tests never kept up.
Multi-App Duplication
Several apps re-implementing the same logic, needing shared Swift packages instead.
Team Capacity Gap
An in-house iOS team that needs an additional senior Swift engineer for a quarter or two.
How We Approach an Existing Swift or Objective-C Codebase
Audit & Risk Map
Dependency currency, deprecated API usage, crash data and test coverage, with the specific risks named.
Test Baseline
Characterisation and snapshot tests capturing current behaviour before anything is changed.
Stabilise First
Fix the crashes and unsupported dependencies that pose immediate risk, ahead of any modernisation.
Migrate Incrementally
Module-by-module Swift conversion and SwiftUI adoption, each step shippable on its own.
Document & Hand Back
Architecture notes, decision records and a walkthrough so your team can continue confidently.
Common Questions About Swift Development
Should we migrate our Objective-C app to Swift?
If the app is actively developed, yes, but incrementally rather than as a rewrite. Swift is where Apple's tooling, frameworks and documentation now point, and the hiring pool for Objective-C keeps shrinking. If the app is stable, rarely changed and generating revenue quietly, a full migration may not be worth it — but you should still get dependencies and deprecated APIs current, because that is what actually breaks on an iOS release.
How long does an Objective-C to Swift migration take?
It depends far more on test coverage than on lines of code. With reasonable coverage, a medium app can be substantially migrated in three to six months of part-time work alongside feature delivery. With no tests, the first phase is writing characterisation tests, which can be a third of total effort. We give a phased estimate after an audit, and each phase delivers a shippable app rather than requiring the whole run to complete.
What is Swift 6 strict concurrency and does it affect us?
Swift 6 enforces data-isolation rules at compile time that were previously only conventions, which turns a class of runtime race conditions into build errors. If you are on an older Swift version it does not affect you until you upgrade, and then it can surface a large number of warnings at once. That is genuinely valuable, since those warnings usually correspond to real intermittent crashes, but it needs planning as a piece of work rather than being absorbed in a routine upgrade.
Can we adopt SwiftUI without rewriting the whole app?
Yes, and that is the normal path. SwiftUI views embed in UIKit through hosting controllers and vice versa, so you can build new screens in SwiftUI while existing ones stay in UIKit. We usually start with a self-contained screen such as settings or a detail view, prove the pattern, then expand. Navigation is the part that needs the most thought, since mixing navigation paradigms carelessly gets messy.
Do you provide Swift developers to work in our team?
Yes. Alongside project work, you can engage senior Swift engineers who work in your repository, your sprint cadence and your code review process, reporting to your lead. Onboarding is typically five to ten business days, with at least four hours of daily overlap with US, UK or Australian hours, on a rolling monthly term.
Can you work on macOS and visionOS as well as iOS?
Yes. Much Swift code shares cleanly across Apple platforms, though interface and interaction models genuinely differ and a Mac app that is an iPad app in a window is obvious to users. For visionOS we would rather be honest: we build for it, and unless you have a specific spatial use case it is usually better treated as an experiment than a launch platform.