Netflix — Backend Engineer ❌ Failed
Level: Unknown Level
Round: Onsite · Type: Multiple Types · Difficulty: 7/10 · Duration: 300 min · Interviewer: Unfriendly
Topics: Behavioral Questions, Data Modeling, System Design, Bucket Sort
Location: Los Gatos, CA
Interview date: 2025-08-15
Got offer: False
Summary
Round 1: Behavioral (BQ)
Question: Proud project with impact.
Round 2: Behavioral (BQ)
Question: Conflict with manager, constructive feedback you give/get, and a challenge you found and resolved.
Round 3: Data Modeling
Question: Designing a DB schema for Netflix employees posting promotions on various platforms like Facebook, YouTube, and TikTok, considering region, i18n, and promotion costs.
Round 4: System Design
Question: Designing a billing system to support 300 million subscriptions, focusing on handling recursive billing. DB scan with cron job and delay queue were considered.
Round 5: Coding
Question: A frequently asked interview question, followed by O(1) bucket sort.
Details
Preparation Tips & Key Takeaways
What I Learned
- Behavioral questions can be a deciding factor, so it's crucial to prepare strong answers.
- Understanding database schema design and system design principles is essential for backend roles.
- Being able to discuss trade-offs and different approaches for system design is important.
Recommended Preparation
Behavioral Questions
- Prepare STAR stories for impact, conflict resolution, feedback, and overcoming challenges.
- Practice articulating your contributions and the impact of your work.
Data Modeling
- Review database schema design principles.
- Study considerations for internationalization (i18n) and regional variations.
System Design
- Study common billing system architectures and recursive billing solutions.
- Understand the trade-offs between DB scan with cron jobs and delay queues.
Coding Practice
- Practice bucket sort and related sorting algorithms.
- Be prepared to discuss the time and space complexity of different algorithms.
Resources I Recommend
- System design resources focusing on billing systems and large-scale subscription management.
- Database design tutorials and best practices.