Okhan Okbay, Developer in Manchester, United Kingdom
Okhan is available for hire
Hire Okhan

Okhan Okbay

Verified Expert  in Engineering

iOS Developer

Manchester, United Kingdom
Toptal Member Since
March 17, 2022

Okhan is a senior iOS developer with over eight years of experience working through all fields of the iOS development ecosystem, from live location tracking on maps to real-time messaging apps. He has worked for various companies, including a $10 billion giant like Getir and an FTSE 100 company like Auto Trader UK. Okhan is keen on developing apps that provide the best user experience, positively impacting users' satisfaction and product growth.


Auto Trader UK
Xcode, Swift, Objective-C, GitHub API, Fastlane
Swift, Objective-C, iOS, Software Architecture, Programming, Modular...
Swift, iOS, Objective-C, Software Architecture, Protocol-Oriented Programming...




Preferred Environment

Xcode, GitHub, Fastlane, Swift

The most amazing...

...app I've worked on was Getir, which was initially launched as a local company in Turkey but then successfully grew into a multinational $10 billion decacorn.

Work Experience

Senior iOS Developer

2021 - PRESENT
Auto Trader UK
  • Contributed daily to the UK's unrivaled automotive advertisement application as a part of a big iOS team—even maintaining its stability is considered a daily success!
  • Integrated Github Actions for daily Firebase build distributions with the help of Fastlane's integral tools.
  • Introduced the VIPER architecture to the app to make it more testable and break the couplings.
Technologies: Xcode, Swift, Objective-C, GitHub API, Fastlane

Senior iOS Developer

2020 - 2021
  • Abstracted the payment layer acting as the central hub for millions of transactions.
  • Worked on the foundational structure of the Getir finance team.
  • Collaborated with the UI/UX designers and prevented faulty designs from coming to life by anticipating implementation issues due to third-party SDK restrictions.
Technologies: Swift, Objective-C, iOS, Software Architecture, Modular, Programming, Continuous Development (CD), Continuous Integration (CI), Protocol-Oriented Programming, APIs, Firebase iOS SDK

Senior iOS Developer

2019 - 2020
  • Integrated in a big agile cross-functional team successfully.
  • Served millions of users in a billion-dollar company and released mission-critical features.
  • Worked on loan, wealth, and trader features and provided support to different teams as an on-demand developer.
Technologies: Swift, iOS, Objective-C, Software Architecture, Protocol-Oriented Programming, APIs

Senior iOS Developer

2018 - 2019
  • Developed a highly performant forum app, which uses all sorts of high-level concurrent programming capabilities.
  • Collaborated with two other iOS developers on the same screens without conflicts following protocol abstractions.
  • Logged non-fatal events to Firebase to get information about the soft errors occurring due to incorrect back-end responses.
Technologies: Swift, Objective-C, iOS, Software Architecture, Modular, Programming, Concurrent Programming, Protocol-Oriented Programming, APIs

Senior iOS Contractor

2017 - 2018
  • Worked as a contractor and a lone iOS Developer of a small agile team and can thrive in that environment as well as I did in massive organizational structures.
  • Developed dependency injection, concurrency, socket servers' client implementations and tricky UI animations.
  • Downsized the socket server costs by nearly more than 30% of what was previously just by utilizing local storage. That kind of a save was crucial for a newly launched startup company.
Technologies: Objective-C, Software Architecture, Concurrent Programming, APIs, Firebase iOS SDK

iOS Developer

2015 - 2017
Wingie Enuygun Group
  • Migrated their Objective-C codebase into Swift and completed the full flight ticket booking app in 1.5 months.
  • Rewrote their hotel room booking app from scratch with RxSwift and MVVM.
  • Worked as the only iOS Developer in the company, managing all the end-to-end processes.
Technologies: iOS, Swift, Objective-C, Xcode

iOS Developer

2015 - 2015
  • Worked on well known brand apps like Coca-Cola, Nestle, and Total.
  • Re-wrote one of their key apps named Earthquake Notifier from scratch with Objective-C.
  • Gained familiarity with the naturally agile environment of digital agencies as part of a three-person iOS development team.
Technologies: iOS, Objective-C, Xcode

iOS Developer

2014 - 2015
Asis Electronics
  • Worked on multiple cities' travel, live location tracking, and payment apps.
  • Had extensive experience with MapKit and Google Maps. Needed to dive deep into the technical limits thereof.
  • Learned the programming language details and developed the apps simultaneously, demonstrating my quick ability to adapt.
Technologies: iOS, Objective-C, Xcode


I collaborated in the design and development of Getir, a super-fast, on-demand delivery service app. It started as a local groceries app and evolved into a massive, multi-billion-dollar, multi-continent company less than five years after its launch. I participated in the process and realized how an organization could grow rapidly.

Auto Trader UK

The UK's number one marketplace to buy a new or used car, with the largest choice of cars for sale. Thousands of retailers and millions of trusted users. A FTSE 100 company is one of the biggest 100 in the UK's market.


I worked on loan, wealth, and trader features and supported cross-functional teams at Akbank, a top-tier banking giant in Turkey that prioritizes agile practices and its tech stack. With millions of daily users and critical features running day and night, even a slight change required too many sanity checks, and I've learned how to deal with it at a massive organization.


Vampr is the number one social platform helping creatives and artists find people with whom to collaborate, create new music, and monetize their work—an essential network that grows with you every step of your journey.

Enuygun - Flight and Hotel

Enuygun is Turkey's leading travel agency with millions of trusted users. It can be thought of as Skyscanner's Turkish version. Users can book flights and make hotel reservations. The user base has been growing rapidly since its first release.

DH | Tech News and Forum

I started to work on a legacy codebase with two iOS developers, parsing different data types (images, videos, gifs, and emojis) and various text fonts and colors and chaining the messages into one another. It was all done natively as if we were creating an HTML parser with Swift, envisioning a complete user forum experience. We've also considered all the concurrency problems and even used dispatch barriers when needed.


Swift, Objective-C


Xcode, GitHub, Fastlane


Protocol-Oriented Programming, Unit Testing, Clean Code, Concurrent Programming, Model View Viewmodel (MVVM), VIPER Architecture, Continuous Development (CD), Continuous Integration (CI), Dependency Injection


iOS, Firebase


Mobile Apps, APIs, Software Architecture, Programming, Modular, GitHub Actions, Firebase Cloud Functions, Typhoon, Reactive Streams, UI Testing


Firebase iOS SDK, GitHub API, Socket.IO, RxSwift

2012 - 2017

Bachelor's Degree in Computer Engineering

Istanbul University - Istanbul, Turkey