Vol. XVI · 16 years of native mobileCharlottesville, Virginia

Vivienne Fosh

Founder and engineer at LanternApps

Kotlin Multiplatform · Mobile platforms · AI products

Mobile platforms in production in months. Builds in minutes.

I architect Kotlin Multiplatform platforms and make large mobile builds fast. Sixteen years of native mobile. Today I also build Kvinta at LanternApps, my own studio.

Work with meSee Kvinta

I’m also open to full-time Staff and Principal roles, remote in the US. Get in touch.

Now

I build Kvinta at LanternApps, my independent studio in Charlottesville, Virginia. Ask it for a document; it researches, writes, cites its sources and checks the facts.

Before that, I built the platforms other teams ship on: a shared Kotlin platform used every day by Charter Communications’ field technicians, 15-minute builds for a 40+ developer org, and the app factory behind about 25 grocery apps. From 2014 I led mobile teams, up to VP of Engineering.

Alongside Kvinta, I take on a few consulting engagements: remote, US time zones.

How I work with teams

By the numbers

Each figure links to the story behind it.

3monthsZero to production for the shared Kotlin platform that replaced Charter Communications’ legacy Android app, the work of 70+ engineers. The web app followed 2 months later.Ascendion · Charter Communications15minCI builds for a 40+ developer org: fully parallel, never queuing. They used to stack into half-day waits.Swiftly6engineersof capacity handed back: roughly 50 engineer-hours of build waiting gone each day, plus $50K a year off CI spend.Swiftly2monthsto ship a stalled, safety-critical United Airlines release with a 20-person team. Build times cut by 75% along the way.Luxoft · United Airlines~50engineers across US and India time zones, on one architecture standard I defined.Ascendion · Charter Communications10M+installs at 99% crash-free, before ARC, when one memory slip crashed the app for millions.Mamba

Selected work

Most recent first

Ascendion

Zero to production in 3 months for Charter Communications’ Kotlin platform.

Principal KMP Architect · Oct 2025 – Apr 2026

A legacy Android app, built by more than 70 engineers, had to be replaced by one Kotlin codebase that delivers Android and a web companion, for field technicians across the country to use every day. The web target ran on a toolchain so new that some of its problems had no public answers.

First production release in 3 months; the web app 2 months later.

  • Kotlin Multiplatform
  • Compose Multiplatform
  • Kotlin/Wasm
  • SQLDelight
  • Gradle convention plugins
  • Helm
  • Kubernetes
  • Datadog
The full story

Every role, in full

How I work

Make the right way the cheap way. Reference implementations, ADRs and a one-plugin module setup put ~50 engineers on one standard, without me in every review.

A mistake you can make twice is a tooling gap. Checksum gates, generated code and coverage ratchets remove whole classes of bugs instead of catching them one at a time.

Adopt early when the downside is contained. Swift in 2014, SwiftUI in 2019, Kotlin Multiplatform in 2021, Kotlin/Wasm in 2025, each in production while it was new. A bet the business can’t absorb waits.

Run the numbers, then build. At Swiftly the cost analysis came first, then the contract, then the migration. Burn, runway and licensing are engineering inputs.

Consulting

  1. Kotlin Multiplatform, from first module to productionIf your KMP roadmap has sharp edges, I’ve probably already hit them.
  2. Mobile platform architecture and rescuesOne standard a whole org can build on, and the migrations to reach it without stopping releases.
  3. Build, CI and release engineeringI make large mobile codebases build fast and ship themselves.
  4. AI features that hold up with real usersI know the difference between an AI demo and an AI product.

Write to vivienne@kvinta.ai.

Writing

The first posts are being written. Notes from the work: what holds up when Kotlin Multiplatform ships at scale, and what it takes to build an AI product that checks itself.

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