iOS Engineer

ASOS; Greater London; On-site; GBP 60,000 - 85,000; Full time

Benefits offered by this job

Employee discount

Private medical care

Job summary

ASOS is seeking a Mid-level iOS Engineer to own analytics and experimentation instrumentation in the iPhone and iPad apps. You will build reliable tracking, collaborate with product and engineering, and ensure data is trustworthy across ASOS’s global app used by millions.

Join a cross‑functional agile team, contribute to Optimizely integrations, and help shape data quality while delivering high‑quality user experiences on iOS.

Qualifications

• Experience building iOS apps with Swift and core frameworks.
• Experience integrating third‑party analytics SDKs into production iOS apps.
• Understanding of how mobile events are batched, queued and flushed, and trade‑offs between data completeness, battery and network usage.
• Knowledge of design patterns and architecture for instrumentation that is easy to adopt by other teams.
• Interest in writing clear, maintainable code and improving existing codebases.
• Awareness of privacy and consent requirements for customer tracking on mobile.
• Comfort debugging data problems and validating payloads with analysts (SQL/Databricks a bonus).
• Familiarity with unit testing and a willingness to contribute to test coverage.
• Experience with UI automation tools.

Responsibilities

• Implement and maintain analytics event tracking in the iOS app following iOS best practices and platform guidelines.
• Translate event specs into instrumentation and ensure events conform to schemas and data contracts.
• Collaborate within an agile, cross‑functional team and review PRs to validate events.
• Investigate and resolve data quality issues and own fixes through to permanent solutions.
• Support experimentation on iOS, including Optimizely integration and experiment exposure.
• Ensure code quality, maintainability, and testing to ship tracking changes safely and reliably.

Skills

Swift

iOS frameworks

Analytics instrumentation

SDK integration

Data privacy

Unit testing

UI automation

Agile teamwork

Data debugging

Maintainable code

Tools

Mixpanel

Optimizely

Databricks

SQL

Job description

Company Description

We're ASOS. We blend our flair for fashion with our love of cutting- edge technology, but more importantly were interested in how we can bring the best out of you.

We exist to give people the confidence to be whoever they want to be, and that goes for our people too. At ASOS, you're free to be your true self without judgment, and channel your creativity into a platform used by millions.

Job Description

We're looking for a Mid-level iOS Engineer to join our Analytics & Experimentation Product Delivery Team and own how customer behavior is captured in our iPhone and iPad apps. This role is about building reliable, well‑governed analytics and experimentation instrumentation at scale, and working collaboratively with product and engineering teams across ASOS to make the data they depend on trustworthy. Our app is used by over 8 million active users globally, maintains an excellent App Store rating, and is built using modern iOS technologies including the latest versions of Swift. You'll be contributing to a mature, well‑supported platform where quality, reliability and user experience matter — and you'll be the iOS voice in a team that spans web, Android, back-end and analytics engineering. What you'll be doing:

• Implementing and maintaining analytics event tracking in the iOS app following iOS best practices and platform guidelines
• Working closely with product managers, analysts and data engineers to translate event specs into instrumentation, and making sure iOS events conform to the agreed schemas, naming conventions and data contracts
• Collaborating within an agile, cross‑functional team, and supporting other ASOS iOS teams who contribute tracking through our inner source model — reviewing pull requests and helping them validate their events
• Investigating and resolving data quality issues, such as discrepancies between platforms or missing and incorrectly populated properties, and taking ownership through to a permanent fix
• Supporting experimentation on iOS, including Optimizely SDK integration, experiment exposure and variant events, and the operational monitoring behind them
• Supporting code quality, maintainability and testing so that tracking changes ship safely and behavioral data stays reliable

Qualifications

About you

• Experience building iOS applications using Swift and the core iOS frameworks
• Experience integrating third‑party SDKs into a production iOS app analytics, experimentation or similar (e.g. Mixpanel, Optimizely) or a strong appetite to pick this up
• An understanding of how mobile events are batched, queued and flushed, and the trade‑offs between data completeness, battery and network performance
• Knowledge of common software design patterns and architecture concepts, and an interest in designing instrumentation that's consistent and easy for other teams to adopt
• An interest in writing clear, maintainable code and improving existing codebases
• Awareness of privacy and consent requirements and how they apply to customer tracking on mobile
• Comfortable debugging data problems as well as codeinspecting payloads, comparing against expected output, and working with analysts to confirm a fix (SQL or Databricks familiarity is a bonus, not a must)
• Familiarity with unit testing and a willingness to contribute to test coverage
• Experience with UI automation tools

Additional Information

What's in it for you?

• Competitive salary, pension, and private medical care scheme
• Performance related bonus
• Flex benefits allowance - which you can chose to take as extra cash, or use towards other benefits
• 25 days paid annual leave + an extra day for your birthday
• Employee discount (hello ASOS discount!)
• Tech Develops - our internal tech focussed skills development programme to focus on your personal growth as a technologist
• Opportunity to represent ASOS at industry leading events
• Opportunity to help shape and drive our DE&I initiatives in Tech (like our WIT movement and Diversity mentoring in Tech)
• Opportunity to make an impact from day one and work with the latest in cutting edge of technology