Senior Mobile SDK Engineer - Lead Level - (iOS/Android)

ZipRecruiter; Guildford; Hybrid; GBP 50,000 - 80,000; Full time

Job summary

A leading tech company in location intelligence seeks a Senior Mobile SDK Engineer to enhance their cross-platform SDKs. The role includes design and development responsibilities, emphasizing performance and integration for iOS and Android applications. Join a dynamic team that values innovation and supports professional growth.

Benefits

5% employer pension contribution

Share option scheme

Flexible and remote working options

28 days holiday plus bank holidays

Budget for learning and development

Discounted memberships to local facilities

Qualifications

• Strong expertise in Swift and Kotlin/Java for mobile SDK development.
• Experience in C programming for core positioning engine.
• Familiarity with Bluetooth Low Energy and iBeacons.

Responsibilities

• Lead SDK development across Swift and Kotlin/Java.
• Manage SDK lifecycle from design to publishing.
• Support app developers integrating our SDKs.

Skills

iOS Development

Android Development

Performance Optimization

Debugging

Bluetooth Low Energy

Job description

Job Description

At Crowd Connected, we’re building the next of location intelligence. Our technology powers real-time tracking and insight for mobile apps, helping businesses better understand how people move through physical spaces—whether that’s at a global music festival, inside a smart building, or across a university campus.

We combine advanced indoor positioning, IoT, and machine learning to deliver solutions that are used by some of the world’s best-known brands and events. Our mobile SDKs for iOS and Android are core to what we do, enabling location-aware experiences at scale—with over 10,000 new downloads of apps containing our code every day.

As a growing scale-up, we operate with the agility and flexibility of a startup, backed by a strong foundation of proven products and real-world deployments. We value autonomy, deep technical thinking, and smart, motivated people who want to have a tangible impact.

The Role: Senior Mobile SDK Engineer

As we scale our technology and customer base in 2025 and beyond, we’re looking for an experienced Senior Mobile Engineer to join our team and take ownership of our cross-platform mobile SDKs.

In this role, you’ll be instrumental in evolving our iOS and Android SDKs—built around technologies like CoreLocation, CoreBluetooth, and CoreMotion. You’ll work close to the metal, designing and refining performant, reliable SDK components that integrate seamlessly with our customers’ apps.

This is not a UI-heavy role—it’s for engineers who enjoy solving low-level problems, care deeply about performance and developer experience, and want to help shape a product used in thousands of apps worldwide.

You’ll have the autonomy to contribute meaningfully to architecture decisions, product direction, and the long-term roadmap. You’ll also help support our growing developer community, ensuring that integration is smooth and well-documented.

If you're a technically curious, hands-on mobile engineer who thrives in a focused, self-directed environment and is excited by the opportunity to build technology that’s already making an impact globally—let’s talk.

Key Responsibilities:

• Lead our SDK Development: Work across Swift (iOS), Kotlin/Java (Android), and C (core positioning engine) to optimise sensor performance, data handling, and network communication.
• Own iOS Expertise: Be the go-to for all things iOS (and ideally Android) —from early design to delivery. Ensure the SDK is scalable, high-performing, and easy to integrate, always aligned with developer needs and business goals.
• Manage Full SDK Lifecycle: Take responsibility for the entire SDK lifecycle, including design, development, testing, integration, and publishing via Carthage, CocoaPods, Swift Package Manager, and Gradle.
• Ensure Quality & Stability: Apply strong debugging and testing skills to maintain robust, reliable SDKs. Champion testing best practices and take pride in delivering production-ready code.
• Support External Developers: Provide hands-on support to app developers integrating our SDKs, helping resolve issues and ensuring seamless onboarding.
• Maintain Clear Documentation: Write and maintain high-quality developer documentation that makes integration smooth and intuitive.
• Contribute to Roadmap & Strategy: Help shape the future of our SDKs by proposing and prioritising new features and improvements based on developer feedback and technical insight.
• Maintain and Improve Supporting Apps: Update and enhance our suite of demo, admin, and internal test apps as needed—ensuring they reflect the latest SDK capabilities.
• Build New Tools as Needed: Design and develop new mobile apps for testing, demos, or admin use to support SDK development and adoption.

Nice to haves:

- Android Experience: Strong iOS experience is required; openness to learning Android development is a definite plus.

- Kotlin Multiplatform - we’re not using it yet, but we’re watching Kotlin multiplatform closely, and it may become part of our stack.

- Experience with Bluetooth Low Energy and iBeacons

- Experience with C. Our core positioning engine is currently written in C, with the same

code-base used by both iOS and Android SDKs

- Experience with memory management, code profiling, and performance optimisation

- Experience with cross platform technologies like React . We need to ensure our

SDKs easily integrate into these frameworks, which are commonly used by our customers.

Benefits:

● 5% employer pension contribution

● Share option scheme

● Flexible and remote working options - we meet in person around once or twice a week.

● 28 days holiday plus bank holidays

● Budget for learning and development

● Discounted memberships to many local facilities, including Surrey Sports Park

Our core company values - CHILE

● Collaboration - You work efficiently, contribute to a high-performing team, and get things

done with minimal friction. Personal productivity and teamwork go hand in hand.

● Honesty - You value transparency, direct communication, and integrity. No politics, no

unnecessary spin—just the truth.

● Innovation - You challenge the status quo, constantly seeking new and better ways to do

things. “That’s just the way it is” isn’t in your vocabulary.

● Learning -You constantly refine your thinking by questioning assumptions, learning from

experience, and embracing new perspectives. You enjoy mastering new , tools, and methods, but more importantly, you find fulfillment in challenging your own beliefs and getting closer to the truth each day

● Excellence - You set high standards while staying practical. You know what needs to be improved today and what’s good enough for now, always striving for better without losing sight of the bigger picture.