System Design (I)

Las entrevistas de System Design se presentan al candidato como un case study. Este formato de entrevista apunta a evaluar habilidades de comunicación, experiencia práctica en situaciones complejas de sistemas reales, curiosidad técnica y versatilidad, y profundidad de conocimientos en diferentes tecnologías.

Estas entrevistas se hacen casi exclusivamente en inglés y por eso es necesario practicar, hablar y presentar en video, y ejercitar distintos tipos de desafíos.

Aprovechá todos los recursos recomendados, los materiales extendidos y la Guía de System Design.

🔗 Recursos

📑 Materiales extendidos

Ejemplos de blog posts que hablan de arquitectura:

• https://discord.com/blog/how-discord-stores-trillions-of-messages (opens in a new tab)
• https://netflixtechblog.com/tagged/software-architecture (opens in a new tab)
• Libreria de Excalidraw para componentes (opens in a new tab)

👨🏼‍💻 Guía de System Design

✅ Practice Checklist

• The deliverable is a white-board style design. If you don’t deliver this, you fail. Get acquainted with expressing solutions at https://excalidraw.com/ (opens in a new tab).

• Practice presenting designs and technical topics in English. Fluidity, Jargon, and articulation of ideas are key. Record yourself and evaluate it.

• Interview practice and mostly passive studies aren’t substitutes for real-world experience of in-depth study. Courses like the one at Educative (opens in a new tab) are great starting points.

• ❌ Do not hand-wave complexity, pretend to understand things you don’t.

• [Opinionated] Develop your solution organically. Don’t add fluff or start with a complicated preset. Real applications are not designed from scratch but incrementally according to the use case.

• Component Checklist

  This is a fundamental list of components and technologies that should be in your toolkit for a system design interview. You should understand each item and the good scenario for using it.

  • Core Components
    • Databases
      • SQL (Postgres)
      • Mongo
      • Wide-tables(ex. Cassandra, ScyllaDB)
      • Key Value stores
        • Redis
        • Storage Buckets (S3)
    • Queues (Async processing)
      • Amazon SQS
      • RabbitMQ
      • Kafka
    • Search (Indexing for use cases)
      • Elastic Search / Solr
    • Caching (efficient content service)
      • DB layer
      • API/APP caching
      • CDNs
  • Frontend Components
    • Caching
    • Client-Side vs Server Side Strategies
    • Static buckets (S3)
    • CDN
    • Edge
    • Real-time / Liveness
    • Lambda & Cloudflare workers
  • Low-Level
    • Fault Tolerance / required components
    • Availability / uptime
    • Scalability / response to surges and growth
    • Sharding / capacity to respond to growth
  • Advanced Concepts
    • Fault Tolerance / required components
    • Availability / uptime
    • Scalability / response to surges and growth
    • Sharding / capacity to respond to growth

• Study the example Interview: Zonaprop https://www.youtube.com/watch?v=Rxn52ROtdTs (opens in a new tab)

📚 Materials

The educative.io (opens in a new tab) course Grokking the System Design Interview (opens in a new tab) is one of the best materials for prepping for system design interviews. It includes the basic theory and system designs to go through and understand them. The content is paid but tremendously useful.

An alternative source for prepping is https://bytebytego.com/ (opens in a new tab).

⚔️ Challenges

Record yourself presenting and talking about each system design challenge. It is important to use both Excalidraw and be constantly speaking.

15m Challenges

1. Design a Meme Generator website
2. Design an email Queueing Service
3. Design a Web Scraper
4. Design a url shortener

45m Challenges

1. Design Twitter
2. Design Uber
3. Design WhatsApp
4. Design Google Docs
5. Design a Stock Broker application
6. [Hard] Design an airline ticketing system

Design OpenSea

• First Stage

  We are going to build a view-only NFT marketplace. Blockchains will be the source of information for items, item pricing, and transactions. We want to show users different NFT collections through a homepage, browse pages and search. We will focus on a web-only experience first.

  We want the experience for the user to be fresh with the latest information from the blockchain.

• Second Stage

  We noticed users are price-aware and sensitive to know the latest pricing and activity in trading NFTs. We would like to add liveness to pricing information on all items, making it a real-time system across the entire website.

  We also want users to be able to create NFTs on our platform through a web-ui and submit it to the blockchain.

• Third Stage

  We are getting constantly DDOS attacked by bots, taking down our website for our regular users. How can we mitigate or solve this issue?

  The platform has various scenarios where things stop working well. What can we do to improve reliability for the following scenarios?

  • Blockchains having downtime
  • Blockchain event processors going down
  • Databases being overloaded and slowing down or going down.
  • API Servers going down
  • Website having frequent application errors

• Example design: https://excalidraw.com/#json=vXQEDdkPeyz4sMROT3YXR,6ry3jAQa6YU8aBDpsITrjg (opens in a new tab)

Architecture Design

1. Explain OAuth