Interview plan template

Use Template
to edit & run interviews

Backend Developer interview questionsSystem Design Interview round

A 60 min interview plan with a time-boxed script, what each question is for, and the signals to score against. Key skills: System Design, Scalability, Microservices, Caching Strategies, Load Balancing.

System Design Challenge

50 min
What this section is for

Purpose

Evaluate technical knowledge and problem-solving skills in real-world scenarios.

•

Design a scalable URL shortening service like TinyURL. Consider aspects like database schema, API design, and handling high traffic.

What this question is for, and what to listen for

Purpose

Assess system design, scalability, microservices, caching strategies, and load balancing skills.

Signals to score

  • Clear understanding of the problem
  • Logical and structured approach
  • Considers scalability and performance
  • Explains thought process
  • Considers edge cases
  • Efficient, clean, well-formatted design
  • Open to feedback and adjusts accordingly

Follow-up questions

  • How would you handle a large number of requests?
  • What database would you choose and why?
  • How would you ensure the system is scalable?
  • Can you explain your thought process on handling data consistency?
•

If you had more time, what would you change in your solution?

What this question is for, and what to listen for

Purpose

Assess the candidate's ability to reflect on their work, identify areas for improvement, and demonstrate critical thinking and problem-solving skills.

Signals to score

  • Recognizes limits in their original answer.
  • Points out clear areas to improve.
  • Suggests specific changes.
  • Talks about how changes could help performance.
  • Shares ideas clearly and logically.
  • Shows a desire to learn and improve.

Follow-up questions

  • What would you do differently if you had more time?
  • Are there any additional features you would consider?
  • How would you improve the system's reliability?
•

Great job on the system design challenge!

What this section is for

Purpose

Provides positive reinforcement to the candidate, helping to build confidence and create a supportive atmosphere before moving into the final part of the interview.

Closing

5 min
What this section is for

Purpose

Thanks the candidate for their time, provides next steps, and leaves a positive final impression.

•

Do you have any questions for me about the team or the company?

What this question is for, and what to listen for

Purpose

Gauge the candidate’s curiosity and interest in the role.

Signals to score

  • Thoughtful questions asked
  • Interest in company culture
  • Curiosity about growth expressed
  • Questions about role raised
  • Inquiries about team challenges
  • Engagement with responses shown
  • Desire to learn next steps
  • Focus on company values expressed

Follow-up questions

  • What interests you most about this team?
  • Are there any areas of the role you’d like to explore further?
Use Template
to edit & run interviews
Interview Template
Position
Backend Developer
Round
System Design Interview for 60 min
Key skills
System Design, Scalability, Microservices, Caching Strategies, Load Balancing

Backend Developer interviews — common questions

Who is this Backend Developer interview plan for?
It is written for the interviewer, not the candidate: the hiring manager, engineer or panel member running the System Design Interview round for a Backend Developer role. It gives you a 60 min script to follow in the conversation — 3 questions with what each one is for and the signals to score against — so you are not writing the round from scratch the night before.
What does the System Design Interview round assess?
This round is focused on: System Design, Scalability, Microservices, Caching Strategies, Load Balancing. It works through System Design Challenge and Closing, scoring against 21 observable signals, with follow-up prompts on all 3 questions for going deeper where an answer is thin.
How is the 60 min split up?
System Design Challenge (50 min), Closing (5 min). The timings are there so the round stays on schedule and every candidate gets the same shape of interview — which is what makes two candidates comparable afterwards.
What other rounds should I run for a Backend Developer?

A single round does not cover a whole role. The other rounds in this library for a Backend Developer: