Senior IOS Engineer

Remote from: Europe
Annual salary: Undisclosed
Salary information is not provided for this position. Check our Salary Directory to estimate the average compensation for similar roles.
Department: Software Engineering
Employment type: Full Time,
Job posted: 7 Jul 2026
Apply before: 7 Aug 2026
Experience level: Senior
Views / Applies: 92 / 2

Crafting Consumer Products of Tomorrow

Actively Hiring

AI Summary

Ruby Labs is seeking a Senior iOS Engineer to develop and maintain high-performance mobile applications. The role involves taking ownership of development processes, collaborating with cross-functional teams, and implementing CI/CD pipelines. Candidates must have 5+ years of iOS experience, expert proficiency in Swift, and deep understanding of UIKit and SwiftUI. The position is remote within CET ±4 hours and offers unlimited PTO and a company-provided MacBook.

Role DNA

Job Complexity

Easy Hard

Pace & Pressure

Relaxed Fast-paced

Autonomy Level

Guided Full Ownership

Communication Load

Independent Highly Collaborative

AI Insight This role requires extensive experience and expertise in advanced iOS technologies, architecture patterns, and CI/CD, making it highly challenging.

Salary Analysis

AI Insight The salary is not specified, but for a Senior iOS Engineer in the US market, the typical range is $120k-$200k, with a median of $150k. This role likely offers competitive compensation.

Core Skills Required

Swift UIKit SwiftUI CI/CD StoreKit 2 Combine MVVM Clean Architecture XCTest Git

Cover Letter Sample

I am writing to express my interest in the Senior iOS Engineer position at Ruby Labs. With over 5 years of professional iOS development experience and a deep expertise in Swift, UIKit, and SwiftUI, I am confident in my ability to contribute to your team.

In my previous roles, I have taken ownership of large-scale B2C mobile applications, implementing clean architectures and CI/CD pipelines that improved deployment efficiency. I am particularly skilled in StoreKit 2 and subscription management, having integrated RevenueCat in past projects.

I thrive in collaborative environments and enjoy working cross-functionally to deliver high-quality features. My experience with automated testing and performance profiling ensures that the apps I build are reliable and optimized.

I am excited about the opportunity to work remotely with Ruby Labs and contribute to innovative consumer products. Thank you for considering my application.

Sample Interview Questions

Can you describe a complex iOS feature you implemented and how you ensured its performance and scalability?

I implemented a real-time collaboration feature using Swift Concurrency and WebSockets. To ensure performance, I used Instruments to profile memory and CPU usage, and implemented lazy loading and efficient data structures. I also designed the architecture with modularization using SPM to allow easy scaling.

How do you handle subscription management and store transactions in a B2C app?

I use StoreKit 2 with RevenueCat for subscription management. I handle purchase flows, receipt validation, and entitlement management. I also monitor server-to-server notifications to handle renewals and cancellations. For testing, I use StoreKit Configuration files and sandbox accounts.

Describe your experience with CI/CD pipelines for iOS apps. What tools have you used?

I have set up CI/CD pipelines using Fastlane and GitHub Actions. I automate code signing, build, test, and distribution to TestFlight and App Store. I also integrate linting and code coverage reports to maintain code quality.

How do you approach code reviews to maintain high standards?

I focus on architecture, readability, and testability. I ensure that new code adheres to our coding standards and patterns. I also look for potential performance issues and edge cases. I provide constructive feedback and encourage discussions to improve the overall design.

Can you give an example of how you optimized app performance using Instruments?

In a recent project, I used Time Profiler to identify a bottleneck in a table view rendering. I found that cell reuse was inefficient due to excessive layout calculations. I optimized by caching cell heights and using prefetching, which reduced scrolling lag by 40%. I also used Allocations to fix a memory leak from a retained closure.

About us

Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we’re always looking for passionate individuals to join us. Learn more about our story at: https://rubylabs.com/about-us/

About the role

As a Senior iOS Engineer, you will play a key role in developing and maintaining our mobile app, ensuring high performance, scalability, and a seamless user experience. You will collaborate closely with the product manager and fellow developers to bring new features to life and continuously optimize our app. Your expertise in Swift and iOS development best practices will be instrumental in driving innovation and maintaining our position as a leader in the App Store.

Key Responsibilities

Develop and maintain a high-quality iOS application with a focus on performance, UI, and UX.
Take ownership of development processes, ensuring clean, maintainable, and scalable code.
Work with cross-functional teams to design, develop, and launch new features.
Implement CI/CD pipelines and deployment best practices.
Conduct code reviews and enforce coding standards.
Profile and optimize app performance (memory, launch time, rendering, battery).
Stay up to date with the latest iOS development trends and integrate relevant advancements.

Qualifications

5+ years of professional iOS development experience.
Experience with B2C mobile apps built on subscription business models.
Expert proficiency in Swift (protocol-oriented design, generics, value semantics, async/await, structured concurrency, actors).
Strong command of StoreKit 2 and subscription lifecycle: purchase flows, receipt/transaction validation, entitlement management, offer codes, and server-to-server notifications (with RevenueCat or a custom equivalent).
Deep understanding of UIKit and SwiftUI, including interoperability, when to use each, and SwiftUI state management (@State, @Observable, @Environment).
Solid grasp of architecture patterns (MVVM, Clean Architecture, Composable Architecture) and modularization for large codebases (SPM modules, feature isolation).
Experience with Combine and/or Swift Concurrency for reactive and async data flows.
Proficiency with CI/CD (Xcode Cloud, Fastlane, Bitrise, or GitHub Actions), Gitflow, code signing/provisioning automation, and TestFlight distribution.
Automated testing experience: XCTest, XCUITest, snapshot testing, and dependency injection for testability.
Strong debugging and profiling skills with Instruments (Time Profiler, Allocations, Leaks, Hangs).
Experience integrating AI-driven features and/or AI-assisted development workflows.
Familiarity with analytics, crash reporting, and A/B testing / feature-flag tooling

Location

Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

Benefits

Discover the perks of being part of our vibrant team! We offer:

Remote Work Environment: Embrace the freedom to work from anywhere, anytime, promoting a healthy work-life balance.
Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize your well-being, without counting days.
Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and recharge.
Company-provided MacBook: Experience seamless productivity with top-notch Apple MacBooks provided to all employees who need them.
Flexible Independent Contractor Agreement: Unlock the benefits of flexibility, autonomy, and entrepreneurial opportunities. Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: https://docs.google.com/document/d/1nkrN76JlZkbKj9WSOhlT1_mni_CZeDkHdwfIjPXVwvk/preview?tab=t.0#heading=h.ndsdl4wapxtt

Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth!

Interview Process

After submitting your application, we conduct a thorough review which typically takes 3 to 5 days, but may occasionally take longer due to the volume of applications received. If we see a potential fit, we proceed with the following steps:

Recruiter Screening (40 minutes)
Technical Interview (60 minutes)
Final Interview (30 minutes)

Life at Ruby Labs

At Ruby Labs, we move fast, aim high, and expect the same from our team. We’re not here to play small—we’re here to build, grow, and win. That means we look for people who are ambitious, driven, and ready to give their best every single day.

This is a place for individuals who thrive under pressure, embrace challenges, and see opportunity in every obstacle. If you’re hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen.

Here, effort is matched with reward. We recognize those who go all in and deliver results, and we create space for people who want more—more responsibility, more growth, and more success.

#LI-Remote

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