Requirements of Twitter’s Design

Define a read-heavy microblogging workload and its consistency boundaries. A successful post, a feed entry, a search result, and a displayed like count can have different freshness requirements.

Requirements

We will outline the system’s functional and non-functional requirements below.

Functional requirements

The system must support the following core features:

• Post tweets: Users can publish messages containing text and media.

• Delete tweets: Users can remove their own content.

• Like or remove a like: Record a user’s current like state for a post. The later sketch calls removal “dislike”; this exercise does not introduce a separate public downvote feature.

• Reply: Users can reply to public tweets.

• Search: Users can search for content using keywords, hashtags, or usernames.

• View timelines: The home timeline contains eligible posts and reposts from followed accounts. A user timeline shows posts by one selected account. Personalized recommendations outside the follow graph are an extension, not part of this following-only baseline.

• Follow or unfollow: Users can follow or unfollow other accounts.

• Retweet: Users can share other users’ public tweets.

Non-functional requirements