Олег

OLEH KOVAL
Senior iOS / Swift Developer · 9 years experience
Kropyvnytskyi, Ukraine · [відкрити контакти](див. вище в блоці «контактна інформація») · [відкрити контакти](див. вище в блоці «контактна інформація») · English: Upper-Intermediate (B2)

SUMMARY
Senior iOS Developer with 9 years of experience designing and shipping scalable mobile applications in
Swift, UIKit, and SwiftUI. Specialized in clean app architecture (MVVM + Coordinators), Swift Concurrency,
and performance optimization, with deep work in real-time media, video analysis, and HealthKit/wearable
integrations. Proven technical leader — code reviews, mentoring, and driving development standards across
cross-functional teams. Early, effective adopter of AI-assisted development (Claude Code), delivering some
features up to 5× faster without sacrificing code quality.

TECHNICAL SKILLS
Languages & Core: Swift, Swift Concurrency (async/await), Objective-C basics
UI: UIKit, SwiftUI, Combine, Core Graphics, Auto Layout
Architecture: MVVM, MVVM + Coordinators, modular & scalable design, refactoring
Media & Real-time: AVFoundation, AVKit, custom video players, WebSocket / SocketIO, Agora SDK
Apple Frameworks: HealthKit, WatchKit, Watch Connectivity, MapKit, PencilKit, PaperKit, In-App
Purchase
Integrations: RESTful APIs, Firebase, third-party SDKs (PolarSDK, FlightScope, MoPub)
AI-Assisted Dev: Claude Code, ChatGPT — AI-driven refactoring, code review, boilerplate generation
Tooling: Xcode (Instruments, memory profiling), Git / GitLab, SwiftLint, CI/CD

SELECTED PROJECTS
Golf Coaching Platform — Sports / Video Analytics Oct 2023 – May 2026
Coaching app letting instructors run online and in-person lessons, record swings on video, and analyze
performance with video-based feedback tools.
• Built a custom video player from scratch with frame-by-frame navigation via a reel control, zoom,
variable playback speed, and automatic screen rotation — the core surface for swing analysis.
• Engineered an offline-first in-person lesson flow: voice notes and swing videos are captured locally and
queued for sequential upload once connectivity is restored.
• Integrated FlightScope launch-monitor radar and Agora SDK for live video calls and streaming between
coach and student.
• Led the design of a chunked upload system for large media files, cutting user complaints related to
uploads by 80%.
• Implemented real-time app updates and chat using SocketIO.
Tech: Swift, UIKit, MVVM + Coordinators, AVFoundation, AVKit, SocketIO, Agora SDK, FlightScope
PHLEX Swimming — Health / Wearables Analytics Jan 2022 – Feb 2026
Swimming analytics platform using Polar Verity Sense and Apple Watch to track workouts and surface technique
and training insights for swimmers and coaches.
• Designed and built the Apple Watch ↔ iOS workout-sync flow, including the watchOS app in SwiftUI.
• Integrated HealthKit and Polar Verity Sense (PolarSDK) to capture and track real-time workout and
sensor data.
• Built a range of performance charts that turn raw sensor data into actionable insights for athletes and
coaches.
Tech: Swift, UIKit, SwiftUI, Combine, HealthKit, WatchKit, Watch Connectivity, Core Graphics, Charts
Social & Dating Application — Social Networking Jul 2017 – May 2020
Social networking and dating app focused on real-time messaging, nearby-match discovery, and profile
interaction.
• Built the application from scratch, owning the architecture (MVVM + Coordinators) and end-to-end
feature delivery.
• Integrated advertising SDKs (MoPub) to support the product's monetization model.
• Ensured feature implementation met App Store Guidelines for a sensitive-content product while keeping
the experience smooth and user-friendly.
Tech: Swift, UIKit, MVVM + Coordinators, MoPub SDK

EXPERIENCE
Onix-Systems — Senior iOS Developer Mar 2022 – Present
• Acted as technical lead on two concurrent projects (development teams of one and two engineers) —
owning architecture decisions, code reviews, and release coordination.
• Mentored 2 developers and helped establish development best practices, improving code consistency
and onboarding across teams.
• Migrated legacy asynchronous code to Swift Concurrency (async/await) and used Instruments for
memory profiling — cutting memory usage by ~30% and reducing retain cycles, leaks, and technical
debt.
• Adopted AI tools (Claude Code, ChatGPT) for refactoring and boilerplate generation, accelerating
delivery of some features by up to 5× while maintaining code quality.
Onix-Systems — iOS Developer Mar 2017 – Mar 2022
• Designed and developed iOS applications in Swift, UIKit, and SwiftUI, delivering scalable and
maintainable mobile solutions.
• Worked with REST APIs, third-party SDK integrations, real-time communication, and multimedia
features including custom video processing and playback.
• Collaborated across backend, Android, QA, design, and clients throughout the full development lifecycle,
focused on code quality, performance, and UX.
Onix-Systems — QA Automation Engineer Jan 2015 – Mar 2017
• Built and maintained automated UI tests (Java, Selenium) executed on each release, with failure
screenshots and detailed reports; performed manual functional, usability, and regression testing of a
retail CRM.

EDUCATION
Master’s degree in Computer Science — Kirovohrad National Technical University2016 – 2018
Bachelor’s degree in Computer Science — Kirovohrad National Technical University2014 – 2016