Cheatsheet for Front End System Design Interviews

RADIO framework

1. Requirements exploration: Understand the problem thoroughly and determine the scope by asking a number of clarifying questions.
2. Architecture / High-level design: Identify the key components of the product and how they are related to each other.
3. Data model: Describe the various data entities, the fields they contain and which component(s) they belong to.
4. Interface definition (API): Define the interface (API) between components in the product, functionality of each APIs, their parameters and responses.
5. Optimizations and deep dive: Discuss about possible optimization opportunities and specific areas of interest when building the product.

Evaluation axes

1. Problem exploration: Demonstrated understanding of the problem, asked clarifying questions to reduce ambiguities and gathered sufficient requirements.
2. Architecture: Broke down the problem into smaller independent parts, defined their responsibilities and how these components can work together.
3. Technical proficiency: Demonstrated technical knowledge and proficiency of front end domain fundamentals (e.g. performance, networking, accessibility, i18n, security, etc), relevant technologies and APIs.
4. Exploration and tradeoffs: Suggested various possible approaches on how to achieve certain functionality, explained the pros and cons and made recommendations.
5. Product and UX sense: Showed consideration for user experience and decisions to make the product a great one.
6. Communication and collaboration: Conveyed thoughts and ideas clearly and concisely, receptive to feedback and collaborated with the interviewer.

Common mistakes

• Jumping into answering the question immediately without first asking questions and gathering requirements.
• Approaching the question in an unstructured manner, going all over the place and missing out on important areas.
• Insisting on only one solution or the best solution without realizing that each solution has tradeoffs.
• Remaining silent the entire time and only thinking in their head.
• Going down a rabbit hole and spending too much time on unimportant areas.
• Using buzzwords without being able to explain them.