Expect to encounter a variety of questions that reflect the technical and interpersonal skills necessary for a Mobile Engineer role at Viber. The following questions are representative of what candidates have faced in past interviews, drawn from 1point3acres.com. They are grouped into key topic categories to help you prepare effectively:

Technical / Domain Questions

This category tests your foundational knowledge and practical skills in mobile development.

• Explain the concept of multithreading and its importance in mobile applications.
• What are some common UI design patterns you have used in your projects?
• Describe how memory management works in Swift.
• How do you handle exceptions in Java?
• What are generics, and why are they useful in Kotlin?

System Design / Architecture

Here you will be assessed on your ability to design scalable and efficient systems.

• How would you design a messaging feature for a mobile application?
• Discuss the considerations you would take into account when building a real-time communication system.
• What architecture would you choose for a mobile app requiring offline capabilities, and why?

Behavioral / Leadership

Expect questions that assess your soft skills and workplace fit.

• Describe a time you faced a significant technical challenge.
• How do you prioritize tasks when working on multiple features?
• Can you provide an example of how you contributed to a team project?

Problem-Solving / Case Studies

These questions evaluate your analytical thinking and problem-solving approach.

• Given a scenario where users report crashes in the app, how would you approach troubleshooting?
• How would you optimize an existing feature that is consuming too much battery on mobile devices?

Coding / Algorithms

Prepare for coding challenges that test your algorithmic skills.

• Write a function in Swift/Kotlin that reverses a string.
• Demonstrate how to implement a simple sorting algorithm.
• Explain the differences in using a linked list versus an array.

This visual timeline illustrates the stages you may encounter throughout the interview process. Use it to effectively plan your preparation and manage your energy levels during interviews. Keep in mind that variations may occur depending on the team and role level.

Deep Dive into Evaluation Areas

In this section, we will explore major evaluation areas relevant to the Mobile Engineer role at Viber. Each area highlights key aspects that interviewers will assess and provides insight into how you can demonstrate your strengths.

Technical Proficiency

Technical proficiency is paramount for a Mobile Engineer. You will be evaluated on your understanding of mobile development languages, frameworks, and tools.

• Swift and Kotlin – Strong knowledge of these programming languages is crucial for mobile development.
• Multithreading – Understanding how to implement and manage multithreading in mobile apps is key.
• UI/UX Principles – Knowledge of user interface design principles will be necessary for creating user-friendly applications.

Example questions or scenarios:

• Explain how you would handle multithreading in a mobile application.
• Describe a challenging UI problem you solved and the approach you took.

Problem-Solving Skills

Your ability to tackle complex problems will be scrutinized. Interviewers will look for structured thinking and creativity in your solutions.

• Debugging – Be prepared to discuss how you identify and fix issues in code.
• Optimization – Understand how to optimize app performance, especially related to battery and memory usage.

Example questions or scenarios:

• Describe your approach to diagnosing a performance issue in a mobile app.
• How would you optimize an API call to reduce latency?

Collaboration and Communication

Since mobile development often involves working in teams, your collaborative skills are vital.

• Teamwork – Be prepared to discuss how you contribute to team goals and support colleagues.
• Stakeholder Communication – You should be able to articulate technical concepts to non-technical stakeholders.

Example questions or scenarios:

• Provide an example of how you resolved a conflict within a team.
• How do you ensure effective communication with product managers and designers?

Key Responsibilities

As a Mobile Engineer at Viber, your day-to-day responsibilities will include developing and maintaining mobile applications, collaborating with cross-functional teams, and ensuring high performance and responsiveness. You will work on projects that involve:

• Implementing new features based on user feedback and business goals.
• Troubleshooting and resolving technical issues that arise in production.
• Conducting code reviews and ensuring best practices are followed.

Your role will require close collaboration with product managers, designers, and other engineers to align on project requirements and deliver high-quality software. You will also participate in discussions about architecture and design decisions that affect the mobile application ecosystem.

Role Requirements & Qualifications

A strong candidate for the Mobile Engineer position at Viber will possess a mix of technical expertise and soft skills.

• Must-have skills:

  • Proficiency in Swift and/or Kotlin.
  • Strong understanding of mobile architecture, UI frameworks, and multithreading.
  • Experience with debugging, optimization, and performance tuning.

• Nice-to-have skills:

  • Familiarity with React Native or other cross-platform frameworks.
  • Knowledge of cloud services and backend integration.
  • Experience in leading small teams or mentoring junior engineers.

Frequently Asked Questions

Q: How difficult is the interview process for a Mobile Engineer at Viber? The interview process can be challenging, particularly in the technical assessments. Candidates should expect to demonstrate both their coding skills and their problem-solving abilities.

Q: What differentiates successful candidates? Successful candidates are those who can clearly communicate their technical knowledge while demonstrating a collaborative spirit and alignment with Viber's mission.

Q: What is the typical timeline from initial screen to offer? The process generally takes 2-4 weeks, depending on scheduling and the number of interview rounds.

Q: How does Viber support remote work? Viber embraces flexible working arrangements, and candidates can discuss their preferences during the interview process.

Other General Tips

• Prepare Thoroughly: Make sure you understand the fundamentals of mobile development. Review relevant technologies and frameworks.
• Practice Coding: Regularly practice coding problems and algorithms to sharpen your skills.
• Align with Company Values: Familiarize yourself with Viber's mission and values to express your alignment during interviews.
• Engage with Interviewers: Use the opportunity to ask questions that demonstrate your interest in the role and company.