iOS Developer, Mobile Ticketing Platform

DataArt is supporting the modernization and development of the IT system for an independent online railway ticket retailer. We hire for the company, not just the project, ensuring ongoing opportunities or paid idle time between assignments.

In this role, you will enhance digital products through data-driven experimentation and analytics. Responsibilities include running large-scale A/B and multivariate tests using tools like Statsig, applying advanced statistical methods such as CUPED and Bayesian Autotune, automating traffic allocation to optimize feature performance, managing feature flagging with gradual rollouts, kill switches, and targeting, and linking feature flags directly to product metrics.

The client engages users through a mobile app, responsive web application, and call center. The system is complex and must comply with numerous regulations.

The system is built on a microservice architecture with continuous integration. Hundreds of components run independently on AWS, increasing modularity and optimizing service usage.

• Refactor and expand the ticket-selling system
• Develop, enhance, and maintain high-quality, scalable code
• Collaborate with cross-functional teams to implement new features and support experimentation initiatives

• 6+ years of iOS development experience using Swift
• Experience in experimentation and R&D
• Hands-on experience with Statsig or similar platforms
• Strong Clean Code and OOP skills
• Knowledge of SwiftUI and UIKit
• Experience with unit testing and working without dedicated QA engineers
• Understanding of SOLID principles
• Familiarity with Agile development methodology
• Good spoken English