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About the Role

We are seeking a highly specialiSed iOS Systems Engineer to join our engineering team as a key Individual Contributor (IC). This role is focused on developing, optimising, and maintaining system-level services, daemons, and low-level platform logic that run reliably and efficiently on a user base of hundreds of millions of devices.

This position demands a deep, genuine curiosity about the internal workings of platforms and a passion for solving complex, low-level technical challenges. Your work is paramount to the user experience, as your primary success metrics will be system stability and battery efficiency. You'll operate with a high degree of autonomy within a structured environment, owning the full lifecycle of complex features.

Key Responsibilities

• System-Level Development: Design, implement, and maintain system services, daemons, and low-level frameworks.
• Architectural Contribution: Serve as a key technical contributor who influences the overall system design and architecture for new features.
• Concurrency & Performance: Write robust, fault-tolerant, and highly efficient code, demonstrating deep expertise in concurrency, specifically for long-running, background components.
• Quality & Testing: Ensure system stability by writing comprehensive unit, system-level, and user acceptance tests (UAT) for core platform logic.
• Automation: Partner with SRE/DevOps to manage deployment automation by contributing to CI/CD pipelines using tools like Jenkins, and using Shell Scripting for other automation tasks.
• Security and Low-Level Comms: Implement robust system logic involving security, privacy, encryption, communication protocols, and Bluetooth.

Must-Have Expertise

• Experience Level: 14+ years of professional software development experience, with proven success building and supporting applications at a massive, global scale.
• Core Languages: Expert proficiency in Swift and experience maintaining an existing Objective-C codebase.
• Concurrency: Deep, practical experience with all aspects of iOS concurrency, including GCD, modern Swift concurrency (Actors, async/await), and thread safety.
• DevOps Focus: Hands-on experience with CI/CD tools and Shell Scripting for development and automation.
• Testing & Quality: Demonstrated commitment to comprehensive testing (Unit, System, UAT).
• System Knowledge: Demonstrated expertise in low-level communication layers, security, and protocols (e.g., Bluetooth, encryption).
• Work Style: A highly autonomous and proactive problem-solver who excels at identifying root causes and building solutions.

Nice-to-Have Skills

• Experience with Containerisation (Docker/Kubernetes) for testing or staging environments.
• Familiarity with other system/platform monitoring tools (Splunk/Prometheus/Grafana).
• Prior experience contributing to the design and architecture documentation for new features.
• Experience working effectively on distributed teams across multiple time zones.

At .Monks, we believe in fostering an environment where a diversity of perspectives can thrive. We proactively work to design hiring processes that promote equity and inclusion while mitigating bias. We celebrate diversity and are committed to building a team that reflects the communities we serve. We welcome and encourage qualified applicants, from all backgrounds, who are excited to contribute to our mission.  

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About Monks 

Monks is the global, digital-first, data-driven, unitary operating brand of S4 Capital plc. With a legacy of innovation and specialized expertise, Monks combines an extraordinary range of global Marketing and Technology Services to redefine how brands interact with the world. Through Monks.Flow, its flagship AI ecosystem for marketing orchestration, Monks transforms marketing into a growth engine, collapsing timelines and connecting brands to culture in real time. By deploying bespoke intelligent agents across disciplines and delivering culturally relevant, high-impact creative and digital solutions, Monks solves key critical business challenges across the entire brand enterprise to help brands sustain long-term impact.

Monks was named a Contender in The Forrester Wave™: Global Marketing Services, ranks among Cannes Lions' Top 10 Creative Companies (2022-25) and remains the only partner featured in AdExchanger’s Programmatic Power Players list every year (2020-24). Named Adweek’s first AI Agency of the Year (2023) and The One Show’s inaugural AI Pioneer Organization, Monks was also awarded Business Intelligence Group’s 2025 Excellence in Artificial Intelligence Award in both the Organizational and AI Product categories. As a trusted partner to cutting-edge innovators in tech, Monks earned titles such as Optimizely Experimentation Partner of the Year (2025), runner-up for the Adobe Firefly Partner Award (2024), and Workato’s AI Visionary Customer Impact Award (2024). Additionally, Monks achieved a record-breaking number of FWAs and continues to hold the most of any partner.

We are an equal-opportunity employer committed to building a respectful and empowering work environment for all people to freely express themselves amongst colleagues who embrace diversity in all respects. Including fresh voices and unique points of view in all aspects of our business not only creates an environment where we can all grow and thrive but also increases our potential to produce work that better represents—and resonates with—the world around us.