Kotlin and Android development services
Android app development in Kotlin and Jetpack Compose for banking, media, shopping, health and connected-device apps, Kotlin Multiplatform apps that share code with iOS, Kotlin back ends on Spring Boot and Ktor, and moves of older Java Android apps to Kotlin, with dedicated Kotlin and Android developers for your team or an app delivered end to end.
What we build with Kotlin and Android
Native Android apps in Kotlin
Kotlin 2 with Jetpack Compose, coroutines and Flow, Hilt for dependency injection, Room and WorkManager for offline data and sync, and a clean split between screens, state and data, targeting the API level Google Play currently requires.
Android banking and fintech apps
Mobile banking, payment and trading apps with passkeys and biometric sign-in, Play Integrity checks, keys held in the Android Keystore, and Google Pay or card tokenisation through the payment provider’s SDK.
Media, streaming and consumer apps
Video and audio on Media3 ExoPlayer with offline downloads, feeds, chat and push notifications through Firebase Cloud Messaging, and Android TV and Google TV versions from the same codebase.
Kotlin back ends on Spring Boot and Ktor
Server-side Kotlin with coroutines, Exposed or jOOQ over PostgreSQL, and an OpenAPI contract the app’s client is generated from, for the API behind an app or a back end in its own right.
Shopping and loyalty apps
Catalogues, carts and checkout with Google Pay, deep links from campaigns, loyalty cards and personalised offers, with analytics events agreed with marketing before release.
Wearable and connected-device apps
Wear OS apps, Health Connect integrations and Bluetooth Low Energy companion apps for fitness trackers, medical sensors and smart home hardware, with health data encrypted on the device.
Kotlin and Compose Multiplatform
Business logic, networking with Ktor and storage with SQLDelight shared between Android and iOS in Kotlin Multiplatform, and the interface shared too with Compose Multiplatform where the design allows.
Moving from Java and XML views
Older Java Android apps moved to Kotlin and Compose screen by screen, with each step released on its own rather than a big-bang rewrite.
Google Play releases and app quality
Signed app bundles, device tests on Google Cloud’s Developer Device Platform (the successor to Firebase Test Lab), baseline profiles for start-up time and staged rollouts through Google Play from a pipeline, with crash and ANR rates watched in Crashlytics and Play Console.
Hire Kotlin and Android developers
Dedicated Kotlin and Android developers
Kotlin and Android developers who join your team full time, work in your repositories, tracker and meetings, and report to your lead. You interview them; we carry the Ukrainian contract, payroll, invoicing and leave.
Kotlin and Android project delivery
A team that takes the Kotlin and Android project from scope to release: estimate, build, tests and deployment, with a technical lead on our side who owns the plan and the quality.
Kotlin and Android support and take-overs
An existing Kotlin and Android system taken over from another team or kept running: a read-only review and a written list of risks first, then fixes and new features in order of impact.
The dedicated team page explains how specialists join your team, and the outsourcing page covers project delivery, take-overs and how we charge.
Who works on your Kotlin and Android project
Android engineers
Kotlin and Jetpack Compose
Kotlin back-end engineers
Spring Boot and Ktor services
iOS and cross-platform engineers
Swift, Kotlin Multiplatform, .NET MAUI and React Native
UI and UX designers
Material 3 designs in Figma
QA engineers
Device testing and automation
How we work on Kotlin and Android
Kotlin for all new code, with detekt and Android Lint in the pipeline, tests from unit level to Compose UI tests, dependencies kept current and a security advisory treated as an unconditional upgrade. Secrets stay out of the app bundle, and anything sensitive on the device is encrypted with keys from the Android Keystore.
Developers work in your repositories, your tracker and your process. The Ukrainian contract, payroll, invoicing and leave stay with us, and everything they write is assigned to you.
Other languages we work in
Java development
Java development services: Spring Boot microservices, banking and payment systems, e-commerce and SaaS back ends, Kafka integrations and legacy modernisation, with dedicated Java developers or project delivery.
Node.js development
Node.js development services: TypeScript APIs, e-commerce and SaaS back ends, fintech integrations, real-time and streaming features and serverless functions, with dedicated Node.js developers or project delivery.
PHP development
PHP development services: Laravel and Symfony applications, e-commerce on Magento, Shopware and WooCommerce, APIs, WordPress and Drupal, and PHP upgrades, with dedicated PHP developers or project delivery.
C and C++ development
C and C++ development services: embedded firmware, Qt desktop software, network and telecom software, low-latency systems, security software and C++ modernisation, with dedicated C++ developers or project delivery.
Go development
Go development services: Golang microservices and APIs, fintech and SaaS back ends, Kubernetes operators, event pipelines and network and security software, with dedicated Go developers or project delivery.
Rust development
Rust development services: backend services and APIs, blockchain and Web3, systems and infrastructure software, security tooling, embedded firmware and WebAssembly, with dedicated Rust developers or project delivery.
Swift and iOS development
iOS app development services in Swift and SwiftUI: banking, shopping, media and health apps, Apple Watch and Vision Pro apps, Objective-C upkeep and App Store releases, with dedicated iOS developers or project delivery.
Scala development
Scala development services: Apache Spark pipelines, fintech and ad tech back ends, services on Akka, Pekko, ZIO or Cats Effect, Play apps and Scala 3 migrations, with dedicated Scala developers or project delivery.
TypeScript development
TypeScript development services: Angular, React and Vue front ends, Node.js back ends, full-stack apps, monorepos and JavaScript to TypeScript migrations, with dedicated TypeScript developers or project delivery.
Questions about Kotlin and Android development
Which industries do your Kotlin and Android developers work in?
Fintech and banking (mobile banking, payment and trading apps), media and consumer apps (streaming, social and entertainment), e-commerce and retail (shopping and loyalty apps), healthcare and fitness (patient, telemedicine and wellbeing apps), enterprise software (field service and internal apps), and connected devices (companion apps for wearables, sensors and smart home hardware).
Do you build Android apps natively or cross-platform?
Both. Native Kotlin with Jetpack Compose when the app depends on platform features such as the camera, Bluetooth or background work; Kotlin Multiplatform when the logic should be shared with iOS; and React Native or .NET MAUI when one codebase for Android and iOS matters more.
Do you write Kotlin for the back end too?
Yes. Spring Boot and Ktor services in Kotlin, for the API behind your app or for a back end of their own, sharing data models with the app through Kotlin Multiplatform where that helps.
How quickly can Kotlin and Android developers start?
When the right Kotlin or Android developer is available, the start is gated only by your interview and the NDA and IP assignment. Otherwise we run a search, which typically produces candidate profiles within two to three weeks, and nobody starts until you have said yes.
How do we hire Kotlin and Android developers through BigTree108?
Tell us the work, the seniority and the hours you need. We propose one or two people with their profiles, you interview them the way you would interview your own hire, and you sign one agreement with BIG TREE 108 LLC and receive one invoice a month.
Who owns the work they produce?
You do. Every specialist has a signed contract with BigTree108 that assigns all work product to the company, and our agreement with you assigns it onward. Code, designs and documents are delivered into your own repositories and tools, not kept where only we can change them.
Building an Android app or a Kotlin back end?
Tell us what the app or service does, who uses it and whether there is an iOS version. You get an answer within one business day: a plan, candidate profiles, or a recommendation on native versus cross-platform.