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≈ $52k – $96k per year (Estimated)
Location
Hybrid (Warsaw, Poland)

Confirmed on the employer's own hiring board on Oct 14, 2026. First seen by Alion on Oct 9, 2026.

Overview
Company
Impact
Profile match
Viber is a messaging and voice-over-IP application owned by Japan's Rakuten that offers free encrypted chats, voice and video calls, group communities, channels and paid Viber Out calls to regular phone numbers. Founded in 2010, the app has hundreds of millions of users, especially in Eastern Europe, the Middle East and Southeast Asia, and runs development centres in Minsk and other cities. The company is headquartered in Luxembourg City, Luxembourg.

Description

Rakuten Viber is one of the most popular and downloaded apps in the world. Working with us provides a unique opportunity to influence hundreds of millions of our users and to be part of the journey that makes us a super-app. Our mission is to make people’s lives easier by enabling meaningful connections, from precious moments with family and friends, through managing business relationships to pursuing their passions.

We invite the iOS developer to the RTC team. Our cross-platform team develops, analyzes and optimizes Viber calls.

Responsibilities

We invite a competent and proactive specialist who knows Swift, Objective-C, C++ that is interested in how the code is executed at the low level. While working with us, he will be engaged in research and development of various aspects of Viber calls on iOS platform:

  • WebRTC library integration and fine-tuning
  • Signaling protocol development
  • Media capturing and processing optimization
  • CPU/traffic/battery consumption optimization
  • Calls statistics gathering and analysis.

We expect that our candidate knows how to work in a team, carefully thinks out technical solutions, knows how to plan his time, correctly prioritize and needs minimal control.

Requirements

  • Deep knowledge of Swift and Objective-C: OOP, data structures, multithreading, interoperability.
  • Experience with WebRTC, iOS CallKit and AVAudioSession.
  • Understanding how a TCP/IP stack works.
  • Intermediate+ level of English.

Advantages

  • Proficiency in C/C++, Java, Kotlin, JS/TypeScript, Bash, Python.
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