The Top 20 Tapjoy Interview Questions and How to Ace Your Interview

Tapjoy is one of the leading players in the mobile advertising and app monetization industry. With its innovative approaches to connecting advertisers with target audiences in meaningful ways, Tapjoy has helped countless app developers enhance monetization while improving user experience.

Landing a job at Tapjoy means joining a company at the cutting edge of mobile technology. However, Tapjoy’s reputation for creativity and innovation also means the interview process can be challenging. This article provides tips and example responses to the most common Tapjoy interview questions helping you demonstrate your qualifications and land the job!

Overview of the Tapjoy Hiring Process

The hiring process at Tapjoy often starts with an initial screening call after a recruiter reaches out through LinkedIn or email. This is followed by a technical phone screen focused on coding and problem-solving skills.

Selected candidates are then invited for 3-5 rounds of onsite interviews. These interviews are typically conducted by hiring managers and senior engineers and consist of both technical and behavioral questions. Some candidates also report giving a coding assignment or presentation.

The questions aim to assess your technical acumen, problem-solving abilities, communication skills and cultural fit. While the process can feel rigorous, being prepared with strong responses can help you stand out.

The Top 20 Tapjoy Interview Questions and Answers

Here are some of the most common Tapjoy interview questions candidates report, along with tips and sample responses:

1. Walk me through your approach to writing clean, maintainable code.

Tip: Emphasize writing modular, well-documented code and your use of design patterns/coding standards. Focus on maintainability.

Sample Response: When writing clean, maintainable code, I follow principles like high cohesion and loose coupling to modularize logic into reusable components. I leverage design patterns like MVC that promote separation of concerns. I ensure variables and functions are descriptively named and document code logic thoroughly. I also adhere to style guides and coding standards across the codebase for consistency. For maintainability, I implement comprehensive unit tests and integrate code reviews into development cycles. I refactor periodically to optimize performance and readability as requirements evolve. These practices produce robust, self-documenting code any engineer can quickly understand and update.

2. How would you improve the performance of an app that is slow or crashing?

Tip: Demonstrate your structured approach to diagnosing and optimizing performance issues.

Sample Response: My first step would be to profile the app to pinpoint bottlenecks. I would use tools like systrace and the Android profiler to isolate expensive operations. Next, I would optimize images, network calls, and inefficient code causing UI lag. I would cache data to limit network requests and introduce background threading to shift heavy work off the UI thread. If crashes persist, I would capture stack traces and logs to identify bug triggers. I’d mitigate crashes by adding checks and handling edge cases. Finally, I would test and monitor under simulated loads, iterating to meet performance SLAs. This systematic process focuses on optimizing app responsiveness and stability.

3. How do you balance delivering features fast with writing tested, high-quality code?

Tip: Discuss prioritizing MVP features, iterating quickly, compromising intentionally, adding tech debt backlogs.

Sample Response: Delivering at speed while maintaining quality requires strategic trade-offs. I focus first on developing the minimum viable product by working closely with stakeholders to identify the absolute essential features. With an MVP established, I work in short iterative cycles allowing for incremental enhancements. If technical debt accrues, I log it to address once critical functionality is met. Compromising consciously is key – I determine acceptable shortcuts but never compromise clean code or testing for mission-critical flows. I also allocate buffer time for unknowns and technical debt to avoid sacrificing quality while delivering quickly. This pragmatic approach allows me to balance speed with stability.

4. How would you design the architecture for an ad serving system?

Tip: Focus on scalability, availability and optimizing delivery.

Sample Response: To architect a highly scalable ad serving system, I would design a distributed microservices architecture on the cloud. Key services would include an ad inventory manager, ad selection engine, analytics module, and API layer for clients. The inventory manager would store and optimize frequently accessed ad data in a fast NoSQL database like DynamoDB. The selection engine would leverage algorithms optimized for low latency ad selection and targeted delivery based on context. I would build redundancy into each service and implement techniques like caching, load balancing, and horizontal scaling to handle massive traffic spikes. I would also collect real-time analytics via events and monitoring to optimize performance. This architecture focuses on maximizing ad relevance while ensuring speed, availability and scalability across audiences.

5. How would you troubleshoot a sudden spike in app crashes?

Tip: Demonstrate methodical root cause analysis and quick identification of issue

Sample Response: In this scenario I would first reproduce the crash, capturing all relevant data – stack trace, device model, OS version, and recent app changes. I would review logs to identify correlations between the spike and any variable, like a specific OS version or device. I would rollback recent changes incrementally to isolate the root cause. If the issue appears inconsistent, I would develop a minimal repro case capturing only the failure flow to consistently recreate it. Once identified, I would implement a hotfix for the specific issue while also creating unit tests to cover the edge case for future prevention. I would then work to refactor the flawed logic, add safety checks, expand test coverage, and implement canary deployments to prevent regressions in the future. The goal is to methodically yet urgently mitigate the immediate crash while implementing safeguards for the long term.

6. How would you improve the security of a mobile app?

Tip: Discuss common mobile app vulnerabilities and mitigation strategies

Sample Response: There are a few areas I would focus on to strengthen mobile app security. First, I would implement certificate pinning and encryption of cached data to prevent man-in-the-middle attacks. Second, I would integrate input validation and sanitization on all external inputs to prevent code injection. Third, I would adopt mechanisms like jailbreak detection and obfuscation to protect against tampering. Finally, I would leverage services like Firebase for real-time monitoring of crashes and exceptions to identify any exploitation attempts. Adding multi-factor authentication and minimum API versions would also harden security posture. The goal is to apply defense-in-depth using layered controls to safeguard user data and prevent exploitation.

7. You see performance in a critical service degrading. What do you do?

Tip: Demonstrate you can quickly identify and resolve performance issues.

Sample Response: First I would confirm the observation by collecting performance data across environments and time intervals. Once validated, I would profile the application to isolate the costly operations. Reviewing recent code changes would provide additional context. Next, I would hypothesize what factors could contribute to degradation such as increased traffic, inefficient queries, blocking calls etc. I would implement caching, concurrent processing, and code optimizations as quick fixes. Longer term, I would refactor to improve efficiency and add monitoring to alert on thresholds. If the issue proved complex, I would loop in other engineers to brainstorm and leverage their expertise. By combining tactical triage with robust monitoring and alerting, I could rapidly resolve the performance deterioration.

8. How do you estimate the time required to complete a project?

Tip: Discuss your process for estimation and how you track/report progress.

Sample Response: I break projects into granular tasks and subtasks across functions to get accurate bottom-up estimates, factoring in precedents and dependencies. I pad estimates to account for unknowns and risks. I align with cross-functional teams early and continually to gain insights into scope and blockers. I track progress transparently, Reporting on time elapsed vs estimated time and adjusting as needed. I re-estimate periodically as requirements evolve. To estimate projects without established scope, I extrapolate from comparable past projects. I provide a range accounting for variability. I also define milestones to deliver incremental value, allowing for course correction. By continually aligning with stakeholders and tracking progress, I provide realistic, data-driven estimates.

9. How do you explain a complex technical concept to a non-technical person?

Tip: Discuss simplifying concepts, using metaphors/analogies, concrete examples

Sample Response: Explaining complex technical topics to non-technical audiences requires translating jargon into accessible language. I start by understanding their background knowledge to gauge the appropriate level. I focus first on the core concept, often relating it to a metaphor or everyday example they can intuitively grasp. For example, explaining the cloud as a toolbox anyone can access on-demand. I break down the complexities around the core idea into bite-sized explanations using plenty of specific examples. I allow time for two-way dialogue, inviting their questions to clarify and refine my explanations. I also incorporate visual aids like diagrams to reinforce technical concepts experientially. Avoiding siloed thinking is key – I aim to contextualize technology in human experiences, speaking to the problems it solves over the intricacies. The goal is building understanding anchored in what’s relevant.

10. How would you improve engagement on a company’s mobile app?

Tip: Showcase analytical abilities and knowledge of engagement optimization tactics.

Sample Response: I would take a data-driven approach to understand our users – analyzing usage metrics to uncover patterns, sticking