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Viber App Development Outsourcing Based on the BOT Model

Viber App Development Outsourcing Based on the BOT Model

Software products
Android, C/C++, PHP
Project team
40 specialists


The Customer is the creator of Viber, a cross-platform VoIP and instant messaging app that now connects over a billion users across the world.


After a release of the iOS app, Viber needed additional development resources to expand their market’s presence with Android and desktop apps. Recruiting in-house developers wasn’t a feasible option in terms of time required, so they considered a long-term partnership with an external vendor. However, they were looking for a deeper developers’ commitment and more operational control than team augmentation or dedicated team outsourcing options provide. To solve the dilemma, they decided to engage with a partner that can offer the Build-Operate-Transfer (BOT) model of cooperation and prepare the ground for opening Viber’s own development center offshore.


Having a prior positive experience with outsourced developers from Europe, Viber chose it as a destination with a good cost/quality balance for their future development center. ScienceSoft became Viber’s partner after successfully conducting PoC for Android’s version of the app. The partnership was divided into 3 stages typical of the BOT model:

Building stage

To select the right talent for the team, ScienceSoft analyzed the Customer’s business goals, internal processes and technical requirements. In 2 weeks, our HR manager assembled mobile (Android and Windows Phone) and desktop development teams with 10 developers in each, 70% of them were of senior level. All candidates were further interviewed and approved directly by the Customer.

ScienceSoft dedicated office space for the team, established communication environment and infrastructure in compliance with Viber’s requirements on security (VPN, access control, data backup) and flexibility (CI/CD pipeline).

Operating stage

Under the Customer’s management, the developers worked in 1-3-week sprints to develop and evolve the Viber mobile app version for Android, Windows Phone and the desktop version for Windows/Mac/Linux. The teams scaled up within a year and were augmented with web backend developers to attain a fully integrated development team.

Daily communication and reporting to the Customer were a part of the engagement driven by the Scrum methodology. During Scrum meetings, the team members analyzed what they had done the day before, what the goals for today were, and whether there were any roadblocks and how to overcome them. This allowed the Customer to have enhanced control and guidance over the project.

Confluence was used to set up a knowledge base that was regularly updated by the developers and served as the basis for transferring project-related knowledge to Viber later on. The operating stage lasted for 2 years.

Transferring stage

Having reached an 800-million user base during the operating stage of the partnership, Viber was ready to move the team assembled by ScienceSoft to their own legal entity. ScienceSoft helped Viber onboard the team that included 40 members by that time, transferred all the assets (infrastructure, knowledge base, intellectual property), and provided financial and legal consultations on setting up business operations in Europe. Senior specialists from the ScienceSoft’s team took up key engineering and managerial roles at Viber’s new development center to support its sustainable growth.


Partnership with ScienceSoft allowed Viber to establish their own fully operational offshore development center in a risk-free and cost-efficient way. At the same time, the Customer leveraged common benefits of outsourcing development: fast project launch, reduced development costs, tapping into a local talent pool without a recruitment headache.

Technologies and Tools

Project management: Confluence, Jira.

DevOps: Jenkins, GitLab.

Android development: Android SDK, Android Studio, Eclipse, ADT Plugin, jarsigner, SQLite, Volley, Gradle, Logcat, UiAutomator.

Windows Phone 7: Windows Phone Toolkit, NLog.

Desktop development: C++Qt, WebRTC, Microsoft Visual Studio.

Web backend development: PHP, MySQL.

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