Hire mobile developers in Ukraine
Native iOS engineers writing Swift and cross-platform engineers writing .NET MAUI, employed by BigTree108 on Ukrainian contracts and embedded full time in your team. You interview them, you direct their work, and you own everything they write.
Two routes, chosen by the product
Native iOS in Swift
When the app leans on platform capabilities or the interface has to feel exactly right. Written against current iOS versions rather than the one the project started on.
Cross-platform in .NET MAUI
One C# codebase reaching iOS, Android, Windows and macOS. Often the right answer for internal and line-of-business apps, where reach matters more than the last ten per cent of native polish.
We staff native iOS in Swift, native Android in Kotlin, and cross-platform apps in .NET MAUI, React Native and Flutter, all on the same terms.
The reason most mobile clients come to us
Not the app: the thing behind it. A mobile-only shop builds your client and then negotiates with whoever owns the API, and you end up arbitrating between two suppliers over whose fault a serialisation bug is. ASP.NET Core on Azure is our largest engineering practice, so the service the app talks to, the identity it authenticates against and the database underneath can all come from the same company and the same code review.
Our own platform is built that way, with .NET on Azure Functions and a front end on top, and we have run it long enough to know which of those architecture decisions were wrong. Read the case study.
What hiring a mobile engineer here includes
The backend from the same team
ASP.NET Core on Azure is our largest practice, so the API your app depends on is written by colleagues rather than by a separate vendor you have to arbitrate between.
Your developer account stays yours
We handle the build, the signing configuration and the submission mechanics on your account under your company name. An app you cannot publish without your supplier is not really yours.
Take-overs welcome
An app somebody else wrote and left is the common case. It starts with a read-only review and a written list of risks in order of user impact, before anyone changes a line.
Releases that are not eventful
Tests with the feature, builds in continuous integration and store submissions treated as a repeatable process rather than a monthly adventure.
IP assigned before access
Every specialist has assigned their work product to BigTree108 and our agreement assigns it onward, so the chain is complete before a repository or a signing certificate is shared.
One contract, one invoice
Ukrainian contracts, tax registration, payroll and leave stay with us. Hours are logged in our portal all month and the same figures produce the invoice.
The mobile development service page covers the same ground from the delivery side, for an app you would hand over rather than staff, and the dedicated team page explains the engagement model in full.
Our record on Upwork
Where our client history is public and verified by the platform rather than written by us.
- Top Rated Plus
- Upwork status of the agency
- 100%
- job success score
- 50
- jobs completed through the agency
- 11,121
- hours worked for clients
Source: BigTree108 agency profile on Upwork, checked 4 September 2026
Questions about hiring mobile developers from Ukraine
Native iOS or cross-platform?
We staff both and the choice should follow the product, not the supplier. Native Swift when the app leans on platform capabilities or the interface has to feel exactly right. .NET MAUI when one C# codebase reaching several platforms is worth more than the last ten per cent of native polish, which is often true for internal and line-of-business apps.
Do you build Android as well?
Yes: natively in Kotlin with Jetpack Compose, or cross-platform from the same codebase as iOS in .NET MAUI, React Native or Flutter. Native iOS in Swift is covered the same way.
Can the same engagement cover the backend the app talks to?
Yes, and it is the reason most mobile clients come to us rather than to a mobile-only shop. ASP.NET Core on Azure is our largest practice, so the API the app depends on is written by colleagues down the hall rather than by a separate vendor you have to arbitrate between.
Who handles the App Store submission?
We do the build, the signing configuration and the submission mechanics, on your developer account under your company name. The account stays yours, because an app you cannot publish without your supplier is not really yours.
Can you take over an existing app?
Yes. Take-overs are a large part of what this company does, nine systems so far with the oldest written in 2008, and a mobile take-over follows the same sequence: a read-only review, a written list of risks in order of user impact, then fixes in that order rather than a rewrite proposal.
Who owns the app and its source?
You do, before anyone starts. Every specialist has assigned their work product to BigTree108 by contract and our agreement assigns it onward to you, so the ownership chain is complete before a repository or a signing certificate is shared.
Need an iOS or .NET MAUI engineer?
Tell us the platforms, whether the backend exists yet and the hours you need covered. You get candidate profiles, or a search that produces them within two to three weeks.