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Hire expert Kotlin developers

Dedicated Kotlin engineers for Jetpack Compose apps, Kotlin Multiplatform shared modules and server-side services, writing structured coroutine and Flow code that your existing Java team can review with confidence.

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A cleaner way to hire Kotlin developers

Hire Kotlin developers through Krapton when you need engineers who write idiomatic Kotlin for Android, shared Kotlin Multiplatform code or JVM backends, rather than Java translated line by line. On Android they build with Jetpack Compose,...

Shortlist
24h
Replacement
30d
IP yours
100%

  • Structured concurrency done correctly

    Coroutines are easy to start and easy to leak. Our engineers launch work in viewModelScope or a supervised scope, collect flows with repeatOnLifecycle or collectAsStateWithLifecycle, never block the main dispatcher, and rethrow CancellationException instead of swallowing it in broad catch blocks.

  • Null safety at Java boundaries

    Kotlin’s null safety weakens at platform types returned from Java. A careful developer adds nullability annotations to Java APIs, avoids scattering the !! operator, and models absent values explicitly, so NullPointerExceptions do not simply move from Java files into Kotlin ones.

  • Compose that recomposes less

    Jetpack Compose performance depends on stable parameters, remembered state and keyed lazy layouts. Developers check recomposition counts in the Layout Inspector, read Compose compiler reports, and hoist state deliberately so screens stay smooth on low-end Android hardware.

  • One language across platforms

    The same engineer can write Android UI, shared business logic in Kotlin Multiplatform modules consumed by iOS, and a Ktor or Spring backend. Sharing models, validation and networking code removes a whole class of drift between mobile clients and the API.

Why Kotlin?

What makes Kotlin the right choice for modern engineering teams.

  • Concise syntax

    Kotlin offers a concise and expressive syntax, reducing boilerplate code and enhancing readability.

  • Interoperability with Java

    Kotlin seamlessly interoperates with existing Java code, allowing gradual adoption and integration.

  • Null safety

    Kotlin incorporates built-in null safety features to prevent null pointer exceptions and improve code robustness.

  • Smart casts

    Kotlin's smart casting feature simplifies type checking and casting, enhancing code conciseness and safety.

  • Coroutines

    Kotlin introduces coroutines for efficient and asynchronous programming, simplifying complex concurrent tasks.

  • Extension functions

    Kotlin supports extension functions, allowing developers to augment existing classes without modifying their code.

What you can build with Kotlin

  • Compose Android apps

    Native Android apps built with Jetpack Compose and Material 3, a single-activity architecture with Navigation Compose, Hilt for dependency injection, and offline-first data through Room and WorkManager.

  • Kotlin Multiplatform modules

    Shared networking, persistence and business rules written once with Ktor client, SQLDelight and kotlinx.serialization, then consumed by Android and by a SwiftUI iOS app through a generated framework.

  • Ktor microservices

    Lightweight HTTP and WebSocket services on Ktor with coroutine-based handlers, content negotiation, JWT authentication and Exposed or jOOQ for database access, packaged as small container images.

  • Spring Boot Kotlin APIs

    Spring Boot services written in Kotlin with constructor injection, data classes for DTOs, the kotlin-spring compiler plugin for proxied classes, and suspend functions in WebFlux where non-blocking IO is justified.

  • Wear OS and TV apps

    Companion apps for watches and Android TV built with Compose for Wear OS and Compose for TV, sharing domain and data layers with the phone app through Gradle modules.

  • Android SDKs and libraries

    Reusable Android libraries for payments, analytics or device features, with a small public API, binary-compatibility checks, consumer ProGuard rules and publication to Maven Central or a private repository.

Idiomatic Kotlin, not translated Java

The most common problem in Kotlin codebases is Java habits carried across. Classes full of mutable var properties and lateinit fields, utility objects where extension functions belong, callback chains where a suspend function would read top to bottom, and the !! operator added whenever the compiler complains. The code compiles, but it gives up the safety the team adopted Kotlin for. Krapton’s Kotlin engineers write the language as intended: immutable data classes, sealed interfaces for UI state and results so when expressions stay exhaustive, value classes for identifiers that must never be mixed up, and scope functions used sparingly so code remains readable. Code review checks these idioms explicitly, and Detekt rules encode the agreed decisions so new contributors follow them without a lecture.

Concurrency is the second area where Kotlin projects slip. Coroutines make asynchronous code look sequential, which hides mistakes: a coroutine launched in GlobalScope outlives its screen, a broad try-catch swallows CancellationException and keeps cancelled work alive, or a repository performs a database call on Dispatchers.Main and freezes the UI. Our developers design scopes first, inject dispatchers so tests can control virtual time, expose StateFlow from ViewModels and collect it with lifecycle awareness, and use supervisorScope where one failed child should not cancel its siblings. On the server the same discipline keeps Ktor handlers from blocking threads with JDBC calls, moving that work to Dispatchers.IO or a dedicated pool. Tests built on runTest verify retries, timeouts and debouncing deterministically instead of relying on sleeps.

What our Kotlin developers know

Every Krapton developer is vetted with real production experience in Kotlin across multiple industry domains.

Hire a developerSchedule a call
  • Kotlin proficiencyExpertise in using Kotlin for developing scalable and maintainable applications.
  • Java interoperabilitySkills in seamlessly integrating Kotlin with existing Java codebases.
  • Null safety implementationMastery of implementing null safety features to enhance code reliability.
  • Coroutines usageProficient in leveraging Kotlin coroutines for efficient and asynchronous programming.
  • Smart casts implementationAbility to utilize smart casts to simplify type checking and casting operations.
  • Extension functionsExperience in creating and utilizing Kotlin extension functions for code modularity.

What our Kotlin developers go deep on

  • Coroutines, flow and channels

    Choosing between StateFlow, SharedFlow and cold flows, applying operators such as flatMapLatest and debounce correctly, injecting dispatchers for IO and CPU work, and testing timing with runTest and Turbine.

  • Jetpack Compose architecture

    Unidirectional data flow with immutable UI state, state hoisting, side effects through LaunchedEffect and rememberUpdatedState, stable parameter types, and screenshot tests with Paparazzi or Roborazzi.

  • Dependency injection and modularization

    Hilt or Koin wiring, feature and core Gradle modules with clear API boundaries, convention plugins in a build-logic project, version catalogs, and KSP replacing kapt to shorten annotation processing.

  • Kotlin Multiplatform setup

    Source set layout with expect and actual declarations, Ktor client engines per platform, SQLDelight schemas, and Gradle configuration that produces an XCFramework or Swift package for the iOS team.

  • Server-side Kotlin

    Ktor plugins for authentication, serialization and call logging, Spring Boot written with Kotlin idioms, Exposed or jOOQ for SQL, and R2DBC drivers where non-blocking database access is genuinely justified.

  • Code quality and release safety

    Detekt and ktlint in CI, R8 shrinking with tested keep rules, binary-compatibility validation for libraries, Crashlytics or Sentry crash reporting, and staged rollouts through the Google Play Console.

Common Kotlin projects we deliver

  • Migrating a Java Android app to Kotlin

    The developer writes new features and tests in Kotlin first, converts high-churn Java classes next, annotates the remaining Java for nullability, and replaces AsyncTask or RxJava chains with coroutines and Flow wherever that simplifies the code.

  • Moving XML layouts to Jetpack Compose

    Screens migrate one at a time using ComposeView inside existing fragments and AndroidView for legacy widgets, so the app keeps shipping. Theme values move into a Compose MaterialTheme that mirrors the existing XML styles during the transition.

  • Sharing logic with an iOS app

    When Android and iOS keep drifting apart on validation and API handling, the engineer extracts that logic into a Kotlin Multiplatform module, keeps native UI on both platforms, and exposes suspend functions and flows to Swift through SKIE.

  • Fixing ANRs and startup jank

    Using Android vitals, Perfetto traces and StrictMode, they move disk and network work off the main thread, defer initialization with App Startup, add Baseline Profiles for critical paths, and confirm the gains with Macrobenchmark tests.

Kotlin solutions by industry

  • Fintech

    Banking and payments apps with BiometricPrompt authentication, encrypted local storage, certificate pinning in OkHttp, and Play Integrity checks that flag tampered or rooted devices.

  • Logistics

    Driver and warehouse apps with background location, barcode scanning through CameraX and ML Kit, offline queues in Room, and sync jobs scheduled reliably with WorkManager.

  • Healthcare

    Patient and clinician apps that pair with wearables over Bluetooth Low Energy, read from Health Connect where users permit it, and keep sensitive records encrypted on the device.

  • Media streaming

    Video and audio apps built on Media3 ExoPlayer with background playback, offline downloads, DRM-protected content and Android TV interfaces written in Compose.

Kotlin vs Java

Java remains a solid, widely known choice for backends, and modern Java has closed part of the gap with records, pattern matching and virtual threads. Kotlin still offers compiler-enforced null safety, coroutines, data classes and concise syntax, and it is Google’s preferred language for Android. Both run on the JVM and interoperate, so the decision is rarely all or nothing.

Kotlin vs Java
DimensionKotlinJava
Null safetyNullable types enforced by the compilerOptional and annotations; compiler does not enforce
ConcurrencyCoroutines with structured concurrency and FlowVirtual threads, CompletableFuture and executors
Android supportPreferred language; Jetpack Compose requires KotlinSupported, but new Jetpack APIs favor Kotlin
BoilerplateData classes, extension functions, default argumentsRecords help; builders and getters remain common
MultiplatformKotlin Multiplatform shares code with iOS and webJVM-focused, with no official iOS code sharing
Build speedSlower compiles, narrowed by the K2 compilerGenerally faster incremental compilation

How to hire Kotlin developers in 5 steps

A transparent, low-risk process — from first call to onboarded engineer in about two business days.

  1. 01Day 0

    Share your brief

    Tell us the stack, scope, seniority and the timezone overlap you need on a free 30-minute discovery call. No obligation, no sales pitch.

  2. 02Within 24 hours

    Review matched profiles

    We shortlist 2–3 pre-vetted Kotlin engineers from our in-house bench, with CVs and directly relevant work — usually within one business day.

  3. 03Days 1–2

    Interview & test

    Interview each developer yourself, run a paid trial task, or do a live pairing session. You decide who joins — we never push a profile.

  4. 04Within 2 days

    Onboard securely

    Sign a free NDA, then plug the developer into your Jira, repository and Slack. Engagements are month-to-month with no lock-in.

  5. 05Ongoing

    Scale or replace

    Scale the team up or down month by month as the roadmap changes. If the fit is not right, you get a free replacement within the first 30 days.

More mobile technologies

Other mobile technologies we work with at Krapton.

Three ways to hire Kotlin developers

Pick the engagement that matches how you actually work. No multi-year contracts — scale up or down month by month.

  • Dedicated developer

    Most popular

    Full-time Kotlin engineer who reports only to you. Best for ongoing products, long-term roadmaps and teams that need a core hire without the HR overhead.

    • 40 hours / week
    • Your Jira, your repo
    • Month-to-month

  • Hourly / time & materials

    Pay only for billable hours. Ideal for research spikes, code audits, or variable-load Kotlin work where scope is still being discovered.

    • Weekly timesheets
    • Slack-first comms
    • No minimum commit

  • Fixed-price milestones

    Scoped delivery with clear milestones and acceptance criteria. Best for well-defined Kotlin builds like an MVP, a migration or a specific module.

    • Scope locked upfront
    • Milestone acceptance
    • Predictable budget

Compare ways to hire Kotlin developers

Pick the model that matches how you work. Switch between them as your Kotlin project evolves — no multi-year contracts.

Compare ways to hire Kotlin developers
EngagementDedicated developer (popular)Hourly / time & materialsFixed-price milestones
Best forOngoing products & long-term roadmapsExploratory or variable-load workWell-scoped MVPs, modules & migrations
BillingMonthly, full-time (~160 hrs)Per billable hourPer accepted milestone
CommitmentMonth-to-month, no lock-inNo minimum commitmentScope locked up front
FlexibilityScale up or down monthlyHighest — pay for what you useLowest — defined deliverables
You manageDay-to-day in your toolsWeekly prioritiesAcceptance criteria only
ReportingDaily standupsWeekly timesheetsMilestone demos

Hire Kotlin developers from anywhere

Our New Delhi team partners with founders and engineering leaders across eight key markets, with enough daily timezone overlap to feel in-house.

  • Hire Kotlin developers in India

    Full working-day overlap

    Krapton is an on-shore Kotlin studio in New Delhi. Hire Kotlin developers in India and get senior, full-time engineers at roughly 50–70% of US/UK rates — with English-fluent communication and IST working hours.

  • Hire Kotlin developers in USA

    4–6 hours of daily overlap — your morning, our evening

    Hire dedicated Kotlin developers for your USA team without the local price tag. US companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

  • Hire Kotlin developers in UK

    Overlap across your whole morning (our afternoon)

    Hire dedicated Kotlin developers for your UK team without the local price tag. UK companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

  • Hire Kotlin developers in Canada

    4–6 hours of daily overlap with ET and PT

    Hire dedicated Kotlin developers for your Canada team without the local price tag. Canada companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

  • Hire Kotlin developers in Australia

    Strong overlap — our morning is your afternoon

    Hire dedicated Kotlin developers for your Australia team without the local price tag. Australia companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

  • Hire Kotlin developers in UAE

    Near-complete overlap — just 90 minutes apart

    Hire dedicated Kotlin developers for your UAE team without the local price tag. UAE companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

  • Hire Kotlin developers in Germany

    Overlap through your morning and our afternoon (DACH)

    Hire dedicated Kotlin developers for your Germany team without the local price tag. Germany companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

  • Hire Kotlin developers in Singapore

    Near-complete overlap — only 2.5 hours apart

    Hire dedicated Kotlin developers for your Singapore team without the local price tag. Singapore companies work with our vetted, full-time Kotlin engineers at 50–70% lower cost than local contractors, with enough daily overlap for live standups, pairing and code review.

Kotlin developer rates

Hire dedicated Kotlin developers from Krapton's team in India. Rates below are blended hourly bands; dedicated developers are billed monthly with no lock-in.

Get a tailored quote

  • Junior (1–3 yrs)

    Feature work under senior review

    $22–$28/hr

  • Mid-level (3–6 yrs)

    Owns modules end-to-end

    $28–$36/hr

  • Senior / lead (6+ yrs)

    Architecture, reviews, mentoring

    $36–$45/hr

Why teams hire Kotlin developers from Krapton

Projects delivered
50+
In-house engineers
60+
Average client rating
4.8/5
On-time delivery
98%

  • Vetted, full-time engineers

    Every Kotlin developer is a full-time, in-house Krapton engineer — never a freelancer or subcontractor.

  • Ready in 24 hours

    Shortlisted Kotlin CVs within a business day and an onboarded developer within two.

  • Clear hourly rates

    Published hourly bands by seniority, billed monthly, with no lock-in.

  • Your IP, your repos

    Full IP assignment, free NDA on request, and all code in your accounts from day one.

  • 30-day replacement

    Not the right fit? Free replacement within five business days in the first 30 days.

  • Real timezone overlap

    4–6 hours of daily overlap with US, UK, EU, UAE and AU teams for live collaboration.

Services that pair well with Kotlin

Most Kotlin engagements also benefit from these Krapton services. Browse full offerings on the services page.

Hire Kotlin developer

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Hiring Kotlin developers — answered

Practical answers to the questions CTOs and founders ask us most often before they hire.

How quickly can I hire a Kotlin developer from Krapton?

Within 24 hours of the initial call. We keep a bench of pre-vetted Kotlin engineers, so once you confirm the brief we line up two or three shortlisted CVs within a business day and can onboard the selected developer within two.

How much does it cost to hire a dedicated Kotlin developer from India?

Blended hourly rates for senior Kotlin engineers typically fall in the $22–$45 USD range depending on seniority and engagement length. Dedicated developers are billed monthly with no lock-in.

Are your Kotlin developers full-time employees or freelancers?

Every Kotlin developer you hire through Krapton is a full-time, in-house engineer — we never subcontract to freelancers or agencies. That means consistent code quality, signed NDAs, and a single point of accountability for your project.

Who owns the code and IP my Kotlin developers write?

You do — 100%. IP assignment and confidentiality are covered by the contract and a free NDA on request. All code lives in your repositories, on your infrastructure, under your accounts from day one.

What should a senior Kotlin developer be able to do?

A senior Kotlin developer designs with the type system rather than around it. They model state with sealed hierarchies, keep nullability honest at Java boundaries, structure coroutine scopes so work cancels predictably, and know when Flow is clearer than callbacks. On Android they understand Compose recomposition and lifecycles; on the server they know which libraries block threads. They also maintain Gradle builds, convention plugins and CI checks independently.

Should we use Kotlin or Java for a new backend service?

Either works, and your team is usually the deciding factor. Kotlin gives you null safety, coroutines and less boilerplate, and both Spring Boot and Ktor support it fully. Java has a larger hiring pool, faster compilation and, since Java 21, virtual threads that simplify blocking-style concurrency. If your Android team already writes Kotlin, sharing one language and data models across mobile and backend is a practical reason to choose it.

How should we hire Kotlin developers to migrate a Java Android app?

Hire for an incremental migration, never a rewrite. Kotlin and Java compile together, so new features and tests can be written in Kotlin immediately while existing Java stays in place. Conversion then targets classes that change often, and nullability annotations on the remaining Java give Kotlin accurate types. Libraries follow: kapt moves to KSP, RxJava gives way to coroutines where that simplifies code, and XML screens move to Compose gradually.

How do your developers test Kotlin and Android code?

They test at unit, integration and UI levels, with coroutine timing under control. ViewModels and repositories get JUnit tests with MockK, kotlinx-coroutines-test and Turbine for flows; Room runs against an in-memory database; Compose screens use the Compose testing APIs plus screenshot tests. Macrobenchmark and Baseline Profile generation cover startup and scrolling performance, and Firebase Test Lab runs suites across a range of real device models.

What changed with Kotlin 2.0 and the K2 compiler?

Kotlin 2.0 made the K2 compiler the default, bringing faster compilation and more consistent type inference, and the Compose compiler moved into the Kotlin repository as a Gradle plugin. Upgrading means aligning the Kotlin Gradle plugin, the Compose compiler plugin and KSP versions, then fixing new warnings or inference differences. Our developers upgrade on a branch, run the full test suite and compare build times before merging.

Keep exploring

More ways to plan your Kotlin build and team with Krapton.

Ready to build with Kotlin?

Get a free 30-minute consultation with our Kotlin team. Clear roadmap, transparent pricing, no obligation.

  • Free NDA on request
  • Response within 24 hours
  • Certified Kotlin developers
  • Flexible engagement models
  • US, UK, UAE & India clients served

Let's start your first project at reasonable prices.

Tell us what you want to build. We'll suggest the right Kotlin developer, timeline, and budget-friendly first milestone.

10% Discount

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Hire a Kotlin developer

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