Oleksandr – Swift, iOS, SwiftUI

Luminus is a Bible microlearning app with conversational AI companions (John the Apostle, King Solomon) — built entirely solo from concept to App Store. The core technical challenge was a real-time STT/TTS pipeline with pre-rendered 3D Rive animations, requiring aggressive latency optimization to feel natural in conversation. I iterated through dozens of versions to nail latency, reliability, and engagement.

• Built and shipped a full real-time STT/TTS conversational pipeline on iOS — custom persona mechanics, latency optimization, and pre-rendered 3D animation sync
• Implemented full mobile attribution stack: SKAdNetwork (SKAN) + Meta Aggregated Events Management (AEM) for paid acquisition measurement and campaign optimization
• Sole owner of product, engineering, design, and App Store distribution — zero to live product

iOS engineer with a track record of shipping high-quality products at scale. At Headway (55M+ downloads, world's #1 book summary app) I led architecture rewrites and UX overhauls that directly moved retention and revenue. Strong in mobile attribution, growth engineering, and paid acquisition. I thrive in product-driven teams where engineering quality and business impact go hand in hand — and I deliver fast

• Redesigned the audio player architecture in 6 weeks, unblocking the Learning team — enabled audio queue (3.6× listenings per session) and GEMs long-form format (24% of all in-app listenings)
• Led Learning Plans, Headway's largest UX overhaul — drove 1.8 summaries consumed per plan vs. 1, and 2nd-day retention +18% among new users
• Migrated iOS to backend-driven A/B testing infrastructure, accelerating ML recommendation iteration — 2nd summary conversion +88%, 1st-to-3rd +12% across all locales
• Rebuilt CI/CD on GitLab with custom distributed runners — cut pipeline time from 52 to 12 minutes
• Improved mobile attribution pipeline with a client-side AppsFlyer fallback — recovered attribution for ~8% of all installs

Shareup is a Berlin-based startup founded by ex-Microsoft, Dropbox, MacPaw, and GitHub engineers, building new.space — a fully-featured end-to-end encrypted distributed file sharing and collaboration platform. I joined as the first iOS hire and grew the app from MVP to a fully-shipped product with 20K MAU and 1M+ files shared monthly. This was a 3-year deep technical engagement covering architecture, cryptography, real-time networking, and high-performance data layers.

• Designed multi-layer E2EE using symmetric + public/private key pairs across complex nested file structures — security architecture designed from first principles
• Co-authored a custom Phoenix WebSocket client for iOS powering real-time sync across devices
• Engineered a high-throughput SQLite data layer handling tens of thousands of writes per second with distributed merge conflict resolution
• Owned the entire iOS client from MVP to 20K MAU — architecture, implementation, App Store delivery, and iteration

AIR Media-Tech is a Kyiv-based media and technology company. I was the first mobile engineer on their crypto R&D team, tasked with building GIM — a custodial crypto wallet operating across a physical ATM network. I proposed and led the adoption of Kotlin Multiplatform (KMP) for shared business logic, while owning the iOS client end-to-end. The product processes real financial transactions at significant volume across multiple countries.

• Shipped a custodial crypto wallet processing $10M+/month across 54 ATMs in Ukraine, Canada, Poland, and UAE
• Proposed KMP architecture for shared business logic between iOS and Android — co-owned the cross-platform layer while leading the iOS client
• Delivered the full iOS app from zero to production in a regulated fintech environment

Receipt Scanner by Saldo Apps is the app for scanning receipts in business trips using OCR technology with the ability to create a trip report. This app is a part of SaldoApps lineup of apps for small business automation.

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• Was fully responsible for this app
• Worked tightly with product owner and designer
• Was a developer advocate for increase app revenue
• Initiated and led analytic mechanism and A/B testing improvement, which allowed product manager to get more insights on user behavior, which allowed us to increase revenue by 30% after four months.

Saldo Apps Platform is a core shared module for all company`s apps: Invoice Maker 2, Receipt Scanner, Mileage Tracker, Checkpie. This module connected core components of all apps: IAP, Networking, Subscriptions Management, Persistence, Analytics, etc.

• Code reviewed
• Tested code
• Initiated creating this shared platform, majorly contributed to it, which led to a 40-60% codebase decrease for Invoice Maker 2, Receipt Scanner, Checkpie, and Mileage Tracker.

Hyfe Cough Tracker - is AI-based cough tracker that helps to record and identify cough trends. It also analyzes cough and gives predictions on a potential diagnosis. He has the most extensive labeled cough database globally, with more than 2M marked coughs.

• Developed the app from scratch leading a team of 2 iOS developers
• Communicated with AI & backend team to ensure smooth recording and cough analyzing flow
• Ensured with the product owner that we meet deadlines
• Made unique audio recording, analyzing and interruption handling solution for Hyfe Cough Tracker, which allowed to record, process, detect and analyze coughs with AI 24/7 using iPhone based on AVAudioEngine.

JuJu Suite - an innovative platform for real estate professionals. This award-winning iPadOS application lets you create and present digital presentations of your residential and commercial properties, sell them, and evaluate every aspect of the process via comprehensive analytics.

• Refactored existing code
• Communicated with the design department on new features and updates
• Communicated with the client on roadmap and deadlines
• Rewrote 80% of JuJu Suite codebase, suggested customer to adapt it to Mac Catalyst, which led to 15% more sales in next two months after release