Top 29 Server Developer Interview Questions and Answers [Updated 2025]

In my last project, I worked on a web application where I collaborated closely with a front-end developer to integrate REST APIs with the UI. We held daily stand-up meetings to discuss progress and challenges. One major challenge was aligning on data formatting, so we created a shared document for API specifications. This clear communication helped us meet our deadlines and deliver a seamless user experience.

I encountered a memory leak in a Node.js server that caused it to crash after several hours of running. I used profiling tools to identify the leak, which turned out to be due to an unclosed database connection. I refactored the code to ensure connections were properly managed, added logging to monitor resource usage, and the server has been stable since. This experience taught me the importance of resource management in server applications.

In my last role, we faced outdated Java-based application servers. The task was to migrate to a microservices architecture on AWS. Key challenges included managing data migration and ensuring minimal downtime. I coordinated with the team, implemented containerization with Docker, and we achieved a 40% increase in system performance post-migration.

In my last project, I had to switch from Node.js to Django for a web application. I enrolled in a Django online course and built a small personal project to practice. This helped me successfully implement a RESTful API within two weeks, improving our application's performance significantly. I learned how crucial it is to embrace new tools to stay effective.

I recently learned Docker to containerize my applications. It allows me to deploy apps consistently across different environments, reducing 'it works on my machine' issues. Now, I can set up local development environments quickly, which has improved my team's productivity significantly.

In a previous role, I had to deploy updates to three different servers within 24 hours. I prioritized based on which server impacted the most users first and then communicated this to my team. I used a task management tool to track progress and completed the tasks on time, leading to a successful update deployment.

In my previous role, I worked on an e-commerce server where the checkout process had many bugs. I implemented unit tests using JUnit for our payment processing module. This helped us catch edge cases early and reduced bugs in production by 30%. We also established a testing guideline for future developers.

I mentored a junior developer in learning Node.js for backend development. We set goals to build a REST API together. I guided them through the project using Git for version control and held weekly check-ins to discuss progress. When they struggled with async programming, I provided additional resources and pair programming sessions. By the end, they successfully deployed their first app.

In a previous job, we faced frequent downtimes due to server overload. I proposed implementing a load balancer to distribute traffic more evenly across our servers. After setting it up, the downtime was reduced by 75%, which significantly improved user satisfaction and kept our service running smoothly.

At my previous job, the server was consistently going down. I used monitoring tools to check logs and identified a memory leak. I then reviewed the application code for inefficient processes, found the culprit, optimized the code, and applied the fix. The server stability improved significantly after that.

I ensure efficient scaling by implementing load balancing, which spreads incoming requests across multiple servers, thus preventing any single server from becoming a bottleneck.

I typically use profiling tools like New Relic to track down performance bottlenecks. For example, I identified a slow database query that was affecting response time and optimized it with indexing.

Common vulnerabilities include SQL injection, XSS, and CSRF. To mitigate SQL injection, I use prepared statements and parameterized queries. For XSS, I ensure proper input escaping and use Content Security Policy. CSRF can be mitigated by implementing anti-CSRF tokens.

When designing a database schema, I first gather the application's requirements to understand the data and its relationships. I ensure data types are correctly selected for efficiency. Normalization is crucial, but I also consider denormalization if it benefits performance. Scalability is key, so I design the schema to accommodate future growth, and I implement indexing for faster queries.

To design RESTful APIs effectively, I ensure that endpoint names are intuitive and reflect the resources they represent. For instance, using /users for user-related actions. I adhere to REST conventions by using GET for retrieving data and POST for creation, and I provide clear documentation so developers understand how to interact with the API.

Load balancing is a technique that distributes incoming network traffic across multiple servers. It ensures that no single server bears too much load, which helps maintain performance. You would use load balancing for web applications to handle high traffic, ensuring availability and reliability.

I prefer Python for server-side automation because of its extensive libraries like Flask for web applications and its readability. I also like Bash for quick scripting tasks in Linux environments due to its speed and simplicity.

I have deployed server applications primarily on AWS using services like EC2 and Elastic Beanstalk. One significant benefit is the scalability; we can easily adjust resources based on traffic. For example, I deployed a microservices architecture using Docker, which allowed seamless updates and rollback strategies.

I manage server code using Git by creating feature branches for each task I work on. I commit often with descriptive messages, and when ready, I open a pull request to get feedback from my peers before merging into the main branch. This process helps maintain code quality and encourages collaboration.

HTTP/2 introduces multiplexing, allowing multiple requests and responses to be sent over a single connection without blocking. This improves server responsiveness compared to the sequential nature of HTTP/1.1. Additionally, HTTP/2 uses header compression to reduce the overhead from repetitive header data, enhancing performance, particularly on mobile and slow connections.

First, I would quickly assess the situation to confirm that the deployment caused the downtime. If it did, I would initiate a rollback to minimize the impact. Meanwhile, I would keep stakeholders informed and update them on our progress. After restoring service, I'd analyze the logs to identify the cause of the issue, ensuring we can avoid it in the future.

I would first acknowledge the client's request and emphasize its importance. Then, I would explain how the feature could impact server performance, using clear metrics. I would suggest alternative options that achieve a similar result without degrading performance significantly. Finally, I would engage the client in a discussion to understand their priorities and document our decisions together.

I would first listen to my colleague's architectural ideas, acknowledging their views. Then I would present my perspective with supporting data. I would suggest we brainstorm together to find common ground or test both designs with a prototype.

First, I would review performance metrics to pinpoint where delays occur. I would analyze database queries and add indexing where necessary. Additionally, I would implement caching layers to minimize repeated data fetching.

First, I would thoroughly review the new regulation to understand what changes are needed. Then, I would assess our current data handling practices to see how they align with the new requirements. Based on that assessment, I would create a detailed plan for making the necessary updates to our server architecture and code. I would implement these changes incrementally, testing the system after each update to ensure everything works as expected. Finally, I would document all changes made and set up compliance checks to ensure we remain aligned with regulations moving forward.

First, I would use top to see which processes are consuming the most CPU. Then, I would check their logs for errors. If they’re part of my application, I’ll analyze and optimize the code or queries causing the high CPU usage.

I would start by outlining the specific requirements of the project like expected load and scaling. Then, I would consider what frameworks my team is already familiar with, such as Express.js for Node or Django for Python, to speed up development. Additionally, I'd check if the framework has a strong community and good documentation since that can save time later on. Finally, if we need to integrate with certain databases or APIs, I'd ensure compatibility with those technologies.

First, I would evaluate the current application's performance and dependencies. Then, I would create a phased migration plan, testing each step on the new infrastructure. Monitoring tools would be set up to detect any issues early. I would also prepare a rollback plan, ensuring we can revert if needed, and keep all stakeholders informed throughout the process.

First, I would identify critical data and systems that need to be protected, then ensure we have automatic backups being stored securely off-site. Additionally, I'd set up failover servers to minimize downtime and define our RTO and RPO to guide our backup frequency and procedures. Finally, I would conduct regular tests of the disaster recovery plan to catch any issues before a real disaster occurs.