Senior System Engineer - iOS

About Nuclei Nuclei is an enterprise SaaS company building the Beyond Banking and Beyond Connectivity products for banks and telecom companies across India, the Middle East, and Europe. We work with 25+ leading BFSI and telecom enterprises. Before we started Nuclei, we listed down a few guiding principles. These were essentially the learnings from our previous startups/companies:

• Think big, think global
• Build a sustainable company, from various perspectives
• Build for the long term, take long term decisions.
• Leverage distribution
• Make our team the core product

What are we looking for? We are looking for a Senior System Engineer to join our iOS SDK team. You will work on our core mobile SDK that is integrated into partner banking and telecom applications. This is not a typical app development role. You will build and maintain a modular SDK that runs inside other companies' apps - handling authentication, secure token management, configuration, theming, and native-to-web communication. Your work directly impacts how millions of users experience lifestyle services inside their banking apps. You will be part of a small, focused integration team working closely with Android and backend engineers.

What You Will Do

• Build and maintain the iOS Core SDK that partners integrate into their apps
• Design clean, well-documented public APIs for partner developers
• Handle SDK end-to-end code with enhancements and maintenance, following best practices and secure coding
• Work with WKWebView for communication between web modules and native code
• Integrate and support the SDK across different partner banking apps — host apps can be native iOS, or cross-platform frameworks like Kony, Flutter, React Native, etc.
• Collaborate with the Android team to keep SDK behaviour and APIs consistent across platforms
• Debug integration issues and support partner developers during onboarding
• Write unit and integration tests for SDK components
• Package and distribute the SDK via Swift Package Manager or CocoaPods

What We Are Looking For

• 4 to 5 years of hands-on iOS development experience with Swift
• Strong understanding of how to build and distribute iOS SDKs/frameworks
• Experience with WKWebView, JavaScript-Native bridging, and secure storage (Keychain)
• Good understanding of iOS app architecture patterns (MVVM, Clean Architecture, or similar)
• Experience working with RESTful APIs and handling networking, caching, and error scenarios
• Understanding of memory management, threading, and performance on iOS
• Ability to write clear, readable code with proper documentation
• Ensure SDK compatibility across multiple iOS versions, device types, and host application environments.
• Develop diagnostic, logging, and monitoring capabilities to simplify partner integrations and troubleshooting.
• Maintain SDK documentation, integration guides, and sample applications.
• Knowledge of App Store release processes, SDK certification and provisioning.

Good to Have

• Experience building SDKs that are integrated into third-party apps
• Exposure to working with banking or fintech applications
• Understanding of security practices - encryption, certificate pinning, secure storage
• Experience with CI/CD pipelines for SDK builds and releases
• Familiarity with accessibility standards on iOS (VoiceOver, Dynamic Type)
• Experience leveraging AI-assisted development tools such as GitHub Copilot, Cursor, Claude Code, ChatGPT, or similar tools to improve developer productivity, code quality, testing, and documentation.