Shared business logic
Domain models, business rules, networking, persistence, and orchestration shared across iOS, Android, web, and backend in pure Kotlin.
Hire Kotlin Multiplatform engineers · Toronto
Hire senior Kotlin Multiplatform engineers in Toronto.
Kotlin Multiplatform for genuine cross-platform code-share: shared business logic across iOS, Android, web, and backend with native UI on each platform. The cross-platform pick when the shared layer matters more than the UI.
- In production
- 2022+
- Senior bench
- 10+ G6/G9 engineers
- Floor
- G6+ on client work
- Canada delivery model
- Cross-border senior bench
Hiring Kotlin Multiplatform engineers in Toronto
Senior Kotlin Multiplatform delivery, anchored in Toronto.
Toronto, Ontario engagements ship with the same seniorKotlin Multiplatform bench used across every Prosigns delivery. No staff-augmentation, no junior fallback, no SDR routing. The engineers in the proposal are the engineers in production.
- Canada delivery model
- Cross-border senior bench
- Operating model
- Dallas HQ + ET/CT business-hour overlap
- Engineering bench
- Senior-only teams
- Reply window
- <2 hr ET
Why senior, not contractor
Kotlin Multiplatform in production is a different problem than Kotlin Multiplatform on a laptop.
Cross-platform mobile is usually a tradeoff between code-share and native feel: React Native and Flutter share UI but cap at the abstraction. Kotlin Multiplatform inverts the tradeoff: share the business logic, networking, persistence, and domain layer; let each platform render with its native UI framework (SwiftUI on iOS, Compose on Android, React on web). Prosigns ships KMP for engagements where the shared layer is genuinely 60–80% of the app and native UX matters too much to abstract.
Senior floor
G6+ minimum
Bench depth
10+ G6/G9 engineers
In production
2022+
Engagement
Outcome-led SOW
Where Kotlin Multiplatform ships
6 sub-areas, grounded in shipped engagements.
Specific applications of Kotlin Multiplatform we’ve built and operate. Every example below maps to a real engagement, not a bullet on a stack-card.
01 02 Native UI per platform
SwiftUI on iOS, Jetpack Compose on Android, Compose Multiplatform for web/desktop where it fits, JetBrains Compose for desktop.
03 Networking + serialization
Ktor Client for HTTP, kotlinx.serialization for type-safe contracts, Ktor Server for the backend tier where it fits.
04 Persistence across platforms
SQLDelight for type-safe SQL across iOS / Android / JVM, Multiplatform Settings for key-value, Realm KMP for object persistence.
05 Migration to KMP
Phased migration from React Native / Flutter / Xamarin / native-only stacks where the shared-business-logic value pays for the migration cost.
06 KMP + Compose Multiplatform
Compose Multiplatform for genuine UI-share across Android / iOS / desktop / web, with platform-specific overrides where UX demands it.
Stack depth
The Kotlin Multiplatform ecosystem, owned.
Frameworks, libraries, and runtime tools the bench has shipped in production. Not a CV-skim, a working depth.
Core
- Kotlin Multiplatform
- Compose Multiplatform
- K2 compiler
- Gradle
Networking + data
- Ktor Client
- kotlinx.serialization
- SQLDelight
- Multiplatform Settings
Async + concurrency
- Coroutines
- Flow
- StateFlow
- atomicfu
DI + architecture
- Koin
- Kodein
- Decompose
- ViewModel-MP
Quality + ops
- Kotest
- Turbine
- Maestro
- Sentry KMP
- Firebase Crashlytics
Engagement models
Three ways to engage Kotlin Multiplatform engineers.
We don’t bill hourly contractors. Engagements run against outcomes, choose the shape that matches the work.
See engagement models- 01
Fixed-scope
Defined deliverable, fixed price
When the deliverable is clear and the scope is bounded: an MVP, a migration, a discrete platform build. Senior engineering against a written outcome, not against a body count.
- 02
Embedded squad
Senior product team, ongoing
When the work is product-shaped and the cadence is continuous. A senior pod (engineering + design + PM as needed) embedded into your team, with the practice lead co-piloting from HELM.
- 03
Managed services
Steady-state operations
When the system is running and needs ongoing engineering ownership: operations, SLO defense, release management, security and compliance evidence. Monthly retainer against a published SLA.
Selected work
Kotlin Multiplatform engineering that shipped.
Financial services
Kotlin Multiplatform migration for a wealth-management app sharing 70% of code across iOS, Android, and a web admin.
70%code shared across platformsMigrated a React Native + separate web admin into a KMP shared layer with SwiftUI / Compose / React frontends. Ktor Client + kotlinx.serialization for the API tier. SQLDelight for offline persistence. Native UX on each platform.
Duration · 8 months
Brief us
Reply < 4 business hoursHave a Kotlin Multiplatform workload? Send a brief.
Five fields. Goes straight to the practice lead, not an SDR. We’ll reply with a senior engineer’s read on fit, scope, and the engagement model that suits the work.
FAQ
Questions buyers ask.
Everything below also appears in the proposal and the SOW: no surprises after signing.
KMP or React Native or Flutter?
KMP when the shared business-logic layer is genuinely 60–80% of the app and native UX matters too much to abstract. RN when JS/TS skills dominate and you want shared UI as well. Flutter when pixel-perfect cross-platform UI is the value. KMP is increasingly our default for serious enterprise mobile where iOS and Android need to feel native.
Is KMP production-ready in 2026?
Yes. KMP went stable in 2023 and the K2 compiler has substantially improved tooling, build times, and the iOS interop story. JetBrains, Touchlab, McDonald's, Philips, and others run KMP in production at scale. Compose Multiplatform is still maturing for iOS but the shared-logic story is solid.
Is this staff-aug, or is it engineering-led delivery?
Engineering-led delivery. We don't bill hourly contractors against your JIRA board. Every engagement runs against a defined outcome with a senior engineer accountable from kickoff to operating cutover. If you genuinely need staff-aug, discrete bodies, your management, hourly rates, we'll be honest and route you to a partner that fits.
What seniority floor are we talking about?
G6 minimum (six-plus years in their craft) on every billable hour. Department leads are G9 or G10. We don't flex juniors onto the bench mid-sprint, we don't subcontract to delivery centers, and we don't dilute senior rates with mixed staffing. The bench in the proposal is the bench in production.
How does pricing work?
Three engagement models published at /engagement-models/. Fixed-scope for defined deliverables, embedded squads for ongoing product work, managed services for steady-state operations. Rates depend on seniority, engagement length, and region. Discovery + scoping conversation is free; SOWs are written against deliverables, not bodies.
Where are your engineers based?
Senior-only across Dallas, Doha, Lahore, and Islamabad. We staff against the engagement's needs (timezone, language, regulatory frame), not against arbitrary regional preferences. Most engagements run with a US/EU-aligned core and a follow-the-sun extended bench when the workload warrants it.
Will the engineers I see in the proposal be the engineers shipping the work?
Yes. We name the engineers in the SOW, attach their profiles, and they're on the kickoff. We don't bait-and-switch with senior reviewers and junior execution. If a named engineer needs to roll off the engagement (rare), we surface a replacement from the same seniority tier with explicit handoff.
Talk to a Kotlin Multiplatform lead
Senior Kotlin Multiplatform engineering, accountable from kickoff.
Bring the workload: we’ll bring a senior engineer plus the practice lead most relevant to the work. 30 minutes, no obligation, no junior reps.