Senior Mobile Engineer

About the Role

We are looking for a Senior Mobile Engineer to maintain and optimize native iOS and Android voice and messaging applications, with a strong focus on Swift (70%) and Kotlin (30%), while leading Proof of Concept work to evaluate migration toward React Native. You will implement and optimize Real-Time Communication capabilities including WebRTC, SIP, and VoIP push notifications, solve complex voice, network latency, and socket reliability challenges, and collaborate directly with client stakeholders on mobile architecture and feature decisions.

What you will do

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

Must haves

• 3+ years of hands-on professional mobile development experience across both iOS and Android platforms.
• Strong, direct experience writing native mobile applications in Swift (iOS) and Kotlin (Android). (Role will be 70% oriented in Swift and 30% oriented in Kotlin.)
• Exposure or knowledge of React Native.
• Solid domain experience with Real-Time Communication (RTC), specifically WebRTC, SIP, or VoIP architecture.
• Proven experience implementing voice-enabled push notifications (e.g., PushKit, CXProvider, VoIP background modes) and handling network latency in voice/chat apps.
• Strong technical problem-solving ability with a senior-level mindset for app stability and connection reliability.
• Based in LATAM or Ukraine with at least 4 hours of EST time zone overlap.
• Excellent written and spoken English communication skills for client-facing collaboration.

Nice to haves

• Direct experience migrating native mobile applications (Swift/Kotlin) to React Native.
• Deep understanding of socket connections, audio packet management, and mobile bandwidth optimization.
• Background in developing specialized VoIP or real-time communication consumer applications.
• Experience working in high-growth startup or dedicated remote agency environments.

Perks and Benefits

• Professional growth

Accelerate your professional journey with mentorship, TechTalks, and personalized growth roadmaps

• Competitive compensation

We match your ever-growing skills, talent, and contributions with competitive USD-based compensation and budgets for education, fitness, and team activities

• A selection of exciting projects

Join projects with modern solutions development and top-tier clients that include Fortune 500 enterprises and leading product brands

• Flextime

Tailor your schedule for an optimal work-life balance, by having the options of working from home and going to the office – whatever makes you the happiest and most productive.