Every system design interview is different. Many of them are open-ended and with multiple possible solutions. However, there are certain steps that could be followed in most of these interviews.

• Understanding the problem
  • This phase involves dissecting and comprehending the problem statement.
  • It includes breaking down complex scenarios, identifying key objectives, and deciphering the primary functionalities required.
  • It’s vital to listen carefully to the interviewer without quickly rushing to a solution.
• Clarifying Questions
  • We should ask targeted questions to fill any gaps in understanding, confirm assumptions, and gather essential details that might not be explicitly stated in the problem description.
  • This is a necessary step, which should never be skipped, even if you feel confident that you understand the problem and have a solution for it.
• Listing the requirements
  • It’s crucial to compile a comprehensive list of functional and non-functional requirements.
  • These encompass specific functionalities, performance expectations, scalability, reliability, security and other critical aspects.
• Back-of-the-envelope estimation
  • This step involves performing quick, rough calculations or estimations to gauge the scale and feasibility of the proposed system.
  • It’s a preliminary assessment to ascertain if the solution aligns with expected performance parameters.
• System APIs
  • Delving into the interfaces and endpoints necessary for communication between system components, APIs form a vital part of system design.
  • Designing these interfaces effectively enables seamless interaction between modules.
• System Overview
  • Providing an overarching view of the system architecture, this step outlines the main components, their interactions, and the flow of data or operations within the system.
• High-level design
  • Building upon the system overview, this phase involves creating a broad architectural layout that outlines the structure of various modules, their responsibilities, and potential communication protocols.
• Database
  • Here, we address the storage requirements, data schemas, database types (SQL, NoSQL), partitioning strategies and data consistency models.
  • We also consider aspects like indexing, querying and scalability.
• Deep dive
  • We need to provide an in-depth description of the important components or modules within the system.
  • This involves scrutinising critical parts in finer detail, often focusing on performance, optimisations, or unique challenges associated with these components.
• Bottlenecks
  • Exploring potential points of failure or limitations in the system’s performance.
  • This phase involves recognising areas that might restrict scalability or cause performance degradation and devising strategies to overcome them.
• Error handling
  • This involves discussing the system’s ability to manage and recover from failures or unexpected scenarios.
  • This includes error detection mechanisms, redundancy strategies and recovery procedures.
• Other topics
  • We may need to cover additional pertinent topics that might arise during the interview.
  • These could encompass security considerations, caching strategies, load balancing mechanisms, or any specific concerns related to the proposed system design.