Senior Mobile Engineer

About the role

AgileEngine is seeking a Senior Mobile Engineer to maintain and enhance native iOS and Android voice and messaging applications. The role focuses on Swift (70%) and Kotlin (30%) development while leading proof‑of‑concept work for a potential migration to React Native. You will also implement real‑time communication features such as WebRTC, SIP, and VoIP push notifications.

Key responsibilities

• Maintain, enhance, and optimize existing native Android (Kotlin) and iOS (Swift) mobile applications.
• Design and build Proofs of Concept (PoCs) to evaluate transitioning native apps to React Native.
• Implement and optimize Real‑Time Communication (RTC) capabilities, including WebRTC, SIP, and in‑app chat features.
• Resolve complex mobile voice issues related to VoIP/voice‑enabled push notifications, socket connections, and network latency.
• Collaborate directly with stakeholders to refine mobile architecture and feature specifications.
• Conduct code reviews, establish best practices for stability, and drive continuous performance improvements.
• Participate in an Agile delivery workflow with regular sprint planning and technical iterations.

Required profile

• 3+ years of professional mobile development experience on both iOS and Android.
• Strong hands‑on experience writing native apps in Swift and Kotlin.
• Exposure to React Native.
• Solid domain experience with RTC technologies such as WebRTC, SIP, or VoIP.
• Proven experience with voice‑enabled push notifications (e.g., PushKit, CXProvider) and handling network latency.
• Senior‑level problem‑solving mindset for app stability and connection reliability.
• Based in LATAM or Ukraine with at least 4 hours EST overlap.
• Excellent written and spoken English for client‑facing collaboration.

Required skills

• Swift
• Kotlin
• React Native
• WebRTC
• SIP
• VoIP push notifications (PushKit, CXProvider)