adsquare Backend Engineer interview questions & guide 2026

The following questions reflect the patterns observed in recent adsquare interviews. These are intended to help you understand the focus areas of their technical assessments rather than providing a rigid list for rote memorization.

Technical Foundations & Coding

These questions test your core programming ability and your grasp of fundamental data structures.

• Find the second largest element in an array.
• Explain the core differences between Java and Kotlin in a production environment.

Success at adsquare requires a blend of technical precision and architectural foresight. Prepare to discuss your previous projects with an emphasis on the "why" behind your technical decisions, especially regarding performance bottlenecks.

Technical Proficiency – You must be comfortable with Java and Kotlin. Interviewers will look for your ability to write clean, maintainable code and your understanding of the JVM ecosystem.

System Architecture – Given the nature of adsquare’s platform, you need to demonstrate how you design systems for scale. Be prepared to talk about distributed systems, latency reduction, and cloud-native patterns.

Professional Communication – You will interact with leads and VPs throughout the process. Articulate your thought process clearly, explain your design trade-offs, and maintain a professional demeanor even when navigating complex or abstract technical problems.

The interview process at adsquare is designed to evaluate both your technical depth and your ability to contribute to a collaborative engineering team. You should anticipate a multi-stage process that typically spans several rounds, moving from high-level leadership discussions to hands-on technical validation.

The process often begins with a conversation with leadership to align on vision and role fit, followed by a practical assessment of your coding abilities, and culminating in deep-dive technical sessions with engineering leads. The rigor is focused on ensuring that candidates can handle the high-throughput demands of the platform while aligning with the team's technical standards.

This timeline provides a high-level view of the progression from initial screening to final technical evaluation. Use this to pace your study, ensuring you are prepared for both the high-level strategic conversations and the granular technical challenges that occur in the later stages.

Technical Depth and JVM Expertise

This area is non-negotiable. You are expected to be an expert in JVM languages. Strong performance involves demonstrating a deep understanding of standard libraries, garbage collection, and language-specific optimizations that improve service performance.

Be ready to go over:

• Concurrency models in Java and Kotlin.
• Profiling and debugging production applications.

As a Backend Engineer, your primary objective is to build and maintain the services that power adsquare’s advertising technology. You will spend your day writing high-performance code, participating in code reviews, and collaborating with your team to optimize data pipelines.

You will work closely with other engineers to ensure that the systems you build can handle massive traffic surges without degrading performance. This involves not only writing features but also proactively identifying bottlenecks in the existing architecture and proposing robust solutions that align with the company’s long-term technical roadmap.

A successful candidate for this role will have significant experience in a high-scale backend environment.

• Must-have skills: Deep expertise in Java or Kotlin, strong grasp of AWS cloud services, and experience designing distributed, high-throughput systems.
• Nice-to-have skills: Prior experience in the AdTech space, familiarity with real-time data processing frameworks, and a solid understanding of CI/CD pipelines.

Q: How long does the entire interview process take? A: While it varies by candidate and team, you should expect a process that spans several weeks, including time for a take-home assignment and multiple rounds of interviews.

Q: What is the most important thing to focus on for preparation? A: Focus heavily on your JVM knowledge and your ability to explain complex system design trade-offs in an AWS environment.

Q: How can I stand out to the interviewers? A: Show that you understand the business impact of your code. Explain not just how you solved a technical issue, but why that solution was the most efficient choice for the business.

• Structure your answers: When explaining your technical experience, use the STAR method (Situation, Task, Action, Result) to keep your responses focused and impactful.
• Be ready for the take-home: Treat the take-home code exercise as production-grade work; clarity and maintainability are just as important as the logic itself.
• Ask questions: Prepare thoughtful questions about the team's current technical challenges to show your engagement and interest in the specific problems they are solving.
• Maintain professionalism: Regardless of the interview format, remain professional and collaborative, as this reflects your ability to work within a team environment.

The Backend Engineer role at adsquare is an opportunity to work at the intersection of massive scale and real-time data. By focusing your preparation on JVM performance, AWS architectural patterns, and clear communication of your technical decisions, you will position yourself as a top-tier candidate.

Remember that you can explore additional interview insights, practice questions, and preparation resources on Dataford to sharpen your skills before your first meeting. Stay focused, be precise, and approach each round as an opportunity to demonstrate your engineering expertise.

The compensation data provided above reflects the current market range for this position in Berlin. Use this information to benchmark your expectations and ensure you are prepared to discuss your requirements confidently during the offer stage.