SwiftUI · Backend migration
Modernizing established mobile apps
I’ve worked on moving an app used by millions to backend v3 and SwiftUI. This involved changing the app’s integration with a new backend version as well as its interface implementation.
Product / Users / Evidence
The problems.
The work.
Misleading funnels, confusing experiments, ad integrations, and app migrations. Here’s the work behind what I say I can do.
Engineering / Product / Data
What the work involved.
What happened, what the investigation found, and what changed. These cases omit company names.
CASE · 016CASE · 001CASE · 004CASE · 006CASE · 007CASE · 009CASE · 010CASE · 011CASE · 012CASE · 013CASE · 014CASE · 015
Four hidden bugs. A broken iOS feed. An emergency release avoided.
The home feed went blank and ads turned white. I traced four defects across SwiftUI, an ad SDK, and bidder configuration, contained the immediate ad failure across app versions, and fixed the underlying code.
They had new registration designs ready. I found the problem in the funnel.
The team thought registration was losing 70% of users. I rebuilt the funnel and investigated the different paths. The step they suspected was working; the first page and the route to login needed attention.
I built a tracking map, found what the refactor lost, and fixed it.
I built an AI-assisted tracking map to compare events before and after a major refactor. It exposed two missing interaction events, and I implemented the fix.
Their A/B test winner performed worse after rollout. I investigated why.
An independent article nobody knew about brought a surge of downloads during the test. I separated that cohort and found that the control performed better for the remaining organic traffic.
They planned to rework the subscription flow. I narrowed down what to investigate.
I investigated why mobile subscription conversion looked worse than web. Different user intent made page views misleading, so the team narrowed the work to the purchase steps and add-to-cart-to-payment conversion.
I worked through onboarding, product questions, and measurement for a fitness app.
I improved registration, introduced Jobs to Be Done and regular product-health metrics, ran onboarding experiments, investigated demand for social features, and reviewed tracking.
The prompt worked as a reminder. The effect did not last.
The team wanted to roll out a homepage prompt. I investigated the raw data and found a short-lived effect for specific users, rather than evidence of a lasting improvement.
They wanted more ad revenue. I rebuilt how the app loads ads.
I built consent-based ad loading for GAM and other ad providers on iOS, added more bidding, and fixed request, configuration, and display issues in the existing integration.
They wanted shared code. I defined the architecture and migrated the business logic.
I migrated business logic for iOS and Android to Kotlin Multiplatform, then started moving UI into shared Compose code.
Shared code had to work for iOS, and for the people shipping it.
I helped a large company adapt its shared-code architecture for both mobile platforms, CI, releases, and everyday development, and recommended how to expand it.
Five A/B tests were running. I untangled how they affected each other.
I compared cohorts, test-group splits, and behavior in the raw data to identify which experiments changed behavior and how they influenced one another.
A whole home in one iPhone and iPad app. I led it from MVP to 1.0.
As lead iOS developer at a smart-home startup, I led a team of up to four developers through the MVP and version 1.0: an offline demo mode, a dedicated iPad experience, encrypted remote access, and real-time sync with the home’s hardware.
In every case, the useful move was not to optimize the first symptom. It was to find the mechanism behind it.
Development / Selected work
Difficult engineering work. Done hands-on.
15+ years of hands-on delivery across new products and established systems. My experience spans native iOS and Android, Flutter, architecture, tests, and automation.
Kotlin Multiplatform · iOS · Android · Compose
Two companies. Two paths to shared code.
For one company, I defined the architecture, migrated business logic for both platforms, and started migrating UI to shared Compose code. For another, I helped adapt the architecture to iOS constraints, CI, releases, and everyday development, then recommended the next steps.
GAM · Other ad providers · iOS
Rebuilding how an app loads ads
I built consent-based provider selection and a simple interface for ad slots, added bidders, and fixed GAM request, configuration, and display issues. Released changes reduced unnecessary requests and improved CPM and impressions; the latest fixes are still awaiting release.
Tests · CI · Automation
Building the systems behind delivery
At Nebenan, my work included modular app structure and CI automation for translations, PR checks, and formatting, plus a Slack-to-Confluence tool for capturing decisions.
Let’s talkBring me
Bring me
the problem.
An app that needs building. A migration that needs someone to own it. Numbers that don’t make sense. A product decision your team can’t resolve. Tell me what’s happening. I’ll tell you whether I’m the right person, how I’d approach it, and what the work would cost.
Email Alex ↗alex@x91tech.comYou bring the context. I take the work seriously.
Not sure what you’d get? See sample reports →