Updated May 17, 2023
Introduction to System Design
System design defines a system’s elements, such as the architecture, components, and modules, the various interfaces of those components, and the statistics that go through that system. The engineering of a logical and effective system is intended to satisfy a business or organization’s specific requirements and needs. It entails an organized approach to the design of a system. A Bottom-Up or Top-Down approach is needed to consider all the related variables of the system. A designer uses modeling languages to convey the data and knowledge in a system defined by a compatible set of rules and definitions. You can describe the designs using either textual or graphical modeling languages.
Some examples of graphical modeling languages are:
- Unified Modeling Language (UML): It describes the software behaviorally and structurally with graphic notation.
- Business Process Modeling Notation (BPMN): It is used for Process Modeling
- Systems Modeling Language (SysML): It is used for systems engineering.
- Flowchart: A symbolic or stepwise depiction of an algorithm.
What should one anticipate in a system design interview?
Such an interview typically starts with a very open-ended problem, such as designing your social network (like Facebook or Twitter). As the discussion progresses, the interviewer will add additional restrictions or assumptions to reduce the scope of the problem.
To tackle these questions, things that help you are practicing and having a structured approach.
If you are looking for a job related to System design, you must prepare for the 2023 System Design Interview Questions. Every interview is indeed different as per the various job profiles. Here, we have prepared the critical System Design Interview Questions and Answers, which will help you get success in your interview.
This 2023 System Design Interview Questions article will present the ten most important and frequently asked System Design Interview questions. These questions are divided into two parts as follows:
Part 1 –System Design Interview Questions (Basic)
This first part covers basic System Design Interview Questions and Answers
Q1) Design TinyURL or bit.ly (a URL shortening service)?
Answer:
Come up with features that the system should support first. Secondly, come up with the estimated numbers of the system’s scalability.
While designing a service, there are three things to consider:
- API(REST API)- The service’s front end is the client’s communication approach with the service and a load balancer.
- Application Layer – worker threads or hosts that take the URL, generate the tiny URL for it and store both in the persistence layer.
- Persistence Layer – Database
Things to analyze:
- Generate a unique ID for each URL and generate IDs at scale since 1000’s URL shortening requests come every second.
- Service handle redirects.
- Support custom URLs.
- Track click stats
- Delete expired URLs
2) Design YouTube/Netflix (a global video streaming service)?
Answer:
Things to analyze:
- In videos, the service will store and transmit a vast amount of data that many users can watch and share simultaneously.
- Record statistics about videos, for example, the overall number of views, up-votes/down-votes, etc.
- Adding comments on videos in real-time.
Components:
- OC – Clouds like AWS and OpenConnect act as content delivery networks.
- Backend – Database
- Client – Any device(Desktop, Android, iPhone) from which you play the video on YouTube/Netflix.
Let us move to the next System Design Interview Questions.
3) Designing Quora/Reddit/HackerNews (a social network + message board service)?
Answer:
Things to analyze:
The people who use the services can share links or post questions. Other users can answer questions or comment on the shared links. So the service should do the following:
- Records stats for each answer, e.g., the overall number of views, up-votes/down-votes, etc.
- Users should be in a position to follow other users or topics
- List top questions on the timeline from all the users and the topics they follow (similar to newsfeed generation).
4) Design Facebook Messenger or WhatsApp (a global chat service)?
Answer:
These are the basic System Design interview questions asked in an interview. Things to analyze:
- Design one on one conversations between users.
- Extending your design to support group chats.
- What can be done when the user is not connected to the internet?
- When to send push notifications?
- How to provide end-to-end encryption?
Structure:
Client > Load balancer > Nodes > Cache(Redis) > Database(Casandra)
5) Design Search Typeahead(Autocomplete)?
Answer:
Things to analyze:
- Type-ahead suggestions to be provided.
- Criteria for choosing the suggestions.
- Does the system need to be real-time?
- Support personalization with suggestions.
- The system handles queries per second.
- Amount of data to be stored.
Part 2 – System Design Interview Questions (Advanced)
Let us now have a look at the advanced System Design Interview Questions.
6) Design Dropbox/Google Drive/Google Photos?
Answer:
Things to analyze:
- How do you upload/view/search/share files or photos?
- Track permissions for file sharing.
- Allowing multiple users to edit the same document.
7) Design Facebook, Twitter, or Instagram?
Answer:
Features to be considered:
- We will support some of the features on Twitter, Facebook, and Instagram.
- Need to keep replies to tweets/grouping tweets by conversations.
- Privacy controls around each tweet.
- Supporting trending tweets
- Direct messaging
- Mentions/Tagging
Things to analyze:
- The system must be capable of handling the number of users and traffic it receives.
- Amount of followers the user has.
- The number of times the tweet has been favored.
Components required to be designed:
- Newsfeed generation
- Social graph
- Systematic search and storage for posts/tweets.
Let us move to the next System Design Interview Questions.
8) Design a Web Crawler?
Answer:
To crawl the entire web and collect hundreds of millions of web documents, a scalable service is essential.
Things to analyze:
- Finding new web pages.
- Prioritizing web pages that change dynamically.
- We must ensure that the web crawler does not stay attached to a single domain indefinitely.
9) Design Uber:
Answer:
These are the frequently asked System Design interview questions in an interview. Architecture: Monolithic/Microservices(Real-time service, Front-end(Application) and database)
- The backend services the mobile phone traffic, and clients connect to the backend over mobile data.
- Clients link to the dispatch system, which matches drivers and riders.
- Dispatch is written almost entirely in node.js.
- Maps/ETA: For dispatch to make an intelligent choice, it is essential to get maps and route data.
- Services: Business logic services use Python as the main programming language.
- Databases: Postgres, Redis, MySQL.
Things to analyze:
- Customers are requesting a ride and how to match them with nearby drivers economically.
- Storing tons of geographical locations for drivers and riders who are always on the move.
- Handling updates to driver locations.
10) Design an API Rate Limiter(Github)?
Answer:
Things to analyze:
- Limiting the number of requests an entity can send to an API within a time window, for example, ten requests per second.
- Rate limiting should work for a scattered setup, as the APIs are reachable through a group of servers.
Recommended Articles
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