Олександр

Oleksandr Chulanov
Senior / Staff iOS Engineer · iOS Tech Lead · Engineering Manager

Kyiv, Ukraine · [open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section)

SUMMARY
Senior iOS Engineer and Engineering Leader with 14+ years of iOS development
experience and 7+ years of engineering management experience. Strong hands-on
background in Swift, Objective-C, UIKit, SwiftUI, concurrency, networking, architecture,
testing, performance and reliability.

Currently working on a large-scale live streaming product with 2M+ DAU and 20M+ MAU,
contributing to both product features and iOS platform/architecture.

Experienced in taking complex mobile systems from architectural problems to measurable
production results. Particularly strong at reducing coupling, improving application reliability,
establishing scalable engineering practices and solving cross-module problems.

I enjoy working close to the code and product, from technical design and architecture
through implementation, release and analysis of production results.

KEY ACHIEVEMENTS
● Improved iOS crash-free rate to 99%+, significantly increasing production stability.
● Designed and implemented ActivityQueue — a centralized coordinator for UI
elements including popups, bottom sheets, keyboards, etc.
● ActivityQueue removed direct dependencies between 100+ modules and
established a mechanism that prevents introducing new unnecessary cross-module
dependencies.
● Applied DORA metrics, contributing to a 30% reduction in production incidents.
● Improved system reliability to 99.93% availability without downtime.
● Worked on a product serving 2M+ daily active users and 20M+ monthly active
users.
● Led development across 4 feature teams, with up to 90 engineers across the wider
engineering organization.
● Helped 7 developers grow into Team Leads, with 1 subsequently progressing to
Engineering Manager.
● Established mobile delivery processes enabling weekly mobile releases.
● Helped transition engineering processes from chaotic delivery to Scrum, TDD/BDD
and measurable engineering practices.
● Introduced and promoted Clean Architecture, Design System and other scalable
engineering practices across mobile development.

TECHNICAL SKILLS
iOS: Swift, Objective-C, UIKit, SwiftUI, Core Animation, Core Graphics, Core Data, AppKit,
XCTest

Concurrency: Swift Concurrency, async/await, Actors, GCD, multithreading

Architecture: Clean Architecture, modular architecture, MVVM, VIPER, TCA, design
patterns, dependency management

Networking: HTTP, REST, WebSockets, socket connections, JSON, networking architecture

Testing: Unit testing, XCTest, TDD, BDD, testable architecture

UI: UIKit, SwiftUI, complex UI flows, custom components, animations, bottom sheets,
popups, Design Systems

Performance & Reliability: crash analysis, crash-free rate, production monitoring,
performance optimization, DORA metrics

Engineering: Git, CI/CD, Scrum, code review, technical leadership, mentoring, architecture
design

PROFESSIONAL EXPERIENCE
Tango Me

https://www.tango.me
On-line (https://apps.apple.com/ua/app/on-line-instant-events/id6749012541?l=ru)

Tango-Live (https://apps.apple.com/ru/app/tango-live-stream-video-chat/id372513032?l=en)

iOS Engineer/ Team Lead / Engineering Manager
September 2021 – Present

Large-scale live streaming platform with approximately 2M+ DAU and 20M+ MAU.

iOS & Technical Contributions

● Develop and architect iOS functionality for a large-scale live streaming application
used by millions of users.

● Work on complex features for both viewers and broadcasters, including the stream
screen, chat, cashier and supporting infrastructure.
● Design solutions for highly interconnected UI and business flows while maintaining
modularity and minimizing dependencies.
● Improved the application’s crash-free rate to 99%+ through reliability improvements,
production analysis and engineering practices.
● Designed and implemented ActivityQueue, a centralized UI interaction manager
responsible for coordinating UI elements such as:
○ popups
○ bottom sheets
○ keyboard presentation
○ etc
● ActivityQueue eliminated direct dependencies between 100+ modules, significantly
reducing architectural coupling and providing a reusable mechanism for introducing
new UI flows without creating additional dependencies.
● Contribute to architecture decisions, technical design, code reviews and
implementation of critical mobile functionality.
● Work with production metrics and DORA metrics to identify bottlenecks and improve
engineering quality and delivery speed.

Leadership

● Manage 4 feature teams
● Work with engineering, product, marketing, sales, support and revenue teams to
translate business requirements into production features.
● Built a development process covering the complete lifecycle from business request
→ technical design → implementation → release → production analysis.
● Helped establish a result-oriented engineering culture focused on measurable
product and engineering outcomes.
● Mentored engineers and team leads, helping 7 developers become Team Leads
and one Team Lead progress to Engineering Manager.

Engineering Impact

● Applied DORA metrics, contributing to a 30% reduction in production incidents.
● Achieved 99.93% availability without downtime.
● Established processes supporting weekly mobile releases.
● Introduced Scrum and helped transition teams from ad-hoc development to
predictable delivery.
● Promoted TDD/BDD, Clean Architecture, Design Systems and other engineering
best practices.

XCDS
(https://apps.apple.com/ua/app/%D0%BC%D0%BE%D0%B9%D0%BE%D1%84%D0%B8%D1%81-%D0%B
4%D0%BE%D0%BA%D1%83%D0%BC%D0%B5%D0%BD%D1%82%D1%8B/id994489415?l=ru)

Engineering Manager / iOS Engineering Manager
April 2015 – September 2021

Project: Collabio / Мой Офис

Cross-platform productivity application for working with documents, spreadsheets,
presentations and PDFs.

● Managed the iOS engineering department.
● Led development of the iOS application using Swift and Objective-C.
● Worked on architecture, technical strategy, development processes and engineering
quality.
● Mentored iOS engineers and supported technical growth of the department.
● Participated in development of complex document-editing functionality and
application infrastructure.
● Introduced and promoted scalable architectural and testing practices.

Technologies: Swift, Objective-C, UIKit, Core Data, Core Graphics, Core Animation,
XCTest, Networking, JSON, Multithreading, Git

Luxoft

Senior iOS Engineer
November 2014 – April 2015

https://itunes.apple.com/ru/app/tin-koff/id455652438?mt=8

https://itunes.apple.com/us/app/citi-private-bank-in-view/id400258878?mt=8

Project: Tinkoff iOS Application

● Developed and maintained the iOS banking application using Objective-C.
● Implemented new product features and fixed production issues.
● Participated in sprint planning, estimation and application architecture discussions.
● Worked on networking, multithreading and complex UI functionality.

Technologies: Objective-C, UIKit, Core Graphics, Core Animation, Core Plot, Git, JSON,
HTTP, socket connections, Multithreading

Project: iLuxAdviser / iStockTrack

● Participated in defining the application concept and technical solution.
● Designed and implemented iOS functionality.

Technologies: UIKit, Core Graphics, Core Animation, Core Plot, SVN, JSON, Networking,
Multithreading

SoftServe
http://softserve.ua/en/

https://itunes.apple.com/us/app/good-for-enterprise/id333202351?mt=8

Senior iOS Engineer / iOS Team Lead

Good for Enterprise / GD SDK iOS

● Maintained and refactored an existing iOS codebase.
● Implemented functional and unit tests.
● Led the iOS part of the team.
● Mentored other developers.
● Improved code quality and maintainability.

Technologies: Objective-C, UIKit, Core Data, Core Graphics, Core Animation, XCTest,
Perforce, JSON, Networking, Multithreading

D-Studio
iOS / OS X Engineer
November 2011 – December 2013

https://itunes.apple.com/us/app/join-it-jigsaw-puzzle/id400711305?mt=8
https://itunes.apple.com/app/letters-app/id474214138?ls=1&mt=8

Join It — Jigsaw Puzzle

● Developed a jigsaw puzzle game with a custom game engine based on OpenGL.
● Implemented iOS functionality and custom rendering.
● Mentored junior developers.
● Supported 9 localizations.

Technologies: Objective-C, UIKit, Core Graphics, Core Animation, Core Data, OpenGL,
Facebook SDK, Twitter SDK, Flurry SDK, JSON, XML, Networking, Multithreading

Letters

● Developed and maintained an iOS application.
● Mentored 2 junior developers.
● Fixed production issues and improved application stability.

OS X Projects

Worked on 2 NDA OS X applications, including application architecture, networking, UI and
multithreading.

Technologies: AppKit, Core Graphics, SVN, JSON, Networking, Multithreading

EDUCATION
Kyiv Polytechnic Institute — Physics and Technical Institute
M.S. in Informatics · 2004–2010

Kyiv Polytechnic Institute
Postgraduate Studies — Information Security · 2010–2013

LANGUAGES
Ukrainian: Native
Russian: Native
English: Advanced