iOS Engineer

Salary: £61,000 - 101,000 per year

Requirements:

• We have experience building iOS applications using Swift and the core iOS frameworks.
• We have experience integrating third-party SDKs into a production iOS app for analytics, experimentation, or similar tools such as Mixpanel or Optimizely, or we have a strong appetite to learn this quickly.
• We understand how mobile events are batched, queued, and flushed, and the trade-offs between data completeness, battery use, and network performance.
• We know common software design patterns and architecture concepts, and we are interested in designing instrumentation that is consistent and easy for other teams to adopt.
• We write clear, maintainable code and improve existing codebases.
• We understand privacy and consent requirements and how they apply to customer tracking on mobile.
• We are comfortable debugging data issues as well as code, inspecting payloads, comparing expected output, and working with analysts to confirm a fix; SQL or Databricks familiarity is a bonus.
• We are familiar with unit testing and willing to contribute to test coverage.
• We have experience with UI automation tools.

Responsibilities:

• We implement and maintain analytics event tracking in our iOS app in line with iOS best practices and platform guidelines.
• We work closely with product managers, analysts, and data engineers to translate event specs into instrumentation and ensure our iOS events conform to agreed schemas, naming conventions, and data contracts.
• We collaborate within an agile, cross-functional team and support other ASOS iOS teams through our inner source model by reviewing pull requests and helping validate events.
• We investigate and resolve data quality issues such as discrepancies between platforms or missing and incorrectly populated properties, and we own fixes through to completion.
• We support experimentation on iOS, including Optimizely SDK integration, experiment exposure and variant events, and the operational monitoring behind them.
• We support code quality, maintainability, and testing so that tracking changes ship safely and behavioral data stays reliable.

Technologies:

• Android
• Databricks
• Support
• Mobile
• Network
• SQL
• Swift
• Web
• iOS
• UX UI Design

More:

We are ASOS, blending fashion with cutting-edge technology to help people feel confident being themselves. You will join our Analytics & Experimentation Product Delivery Team as a Mid-level iOS Engineer, supporting a mature and well-supported app used by over 8 million active users globally. Our iOS app is built with modern technologies including the latest versions of Swift, and you will work across a cross-functional team spanning web, Android, back-end, and analytics engineering. We offer a competitive salary, pension, private medical care, performance-related bonus, flex benefits allowance, 25 days paid annual leave plus your birthday off, employee discount, Tech Develops learning opportunities, chances to represent ASOS at industry events, and the opportunity to help shape our DE&I initiatives in Tech.

last updated 35 week of 2026