Research Engineer, SysML - FAIR

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Write code to parse regular expressions including * (0 or more characters), + (1 or more characters), and . (1 exact character). For example: parse(a., ab) should return true. parse(a*, aaa) should return true. parse(a+, a) should return true. parse(a+, ) should return false. parse(a.*b, axyzb) should return true. parse(a.*b, axyz) should return false. parse(abc, abc) should return true. parse(abc, abd) should return false. Your function should take two strings as input: the regular expression and the string to match against. It should return a boolean indicating whether the string matches the regular expression. Focus on handling the special characters ., *, and +. Assume that other characters in the regular expression must match literally. Explain your approach and provide a clear, well-documented code implementation. Consider edge cases such as empty strings and null inputs. Also think about the time and space complexity of your solution, and try to optimize it for performance. Can you provide a solution using dynamic programming?

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Let's design a new feature for the Facebook app: Ephemeral Groups. These groups function like regular Facebook groups but with a key difference: all content (posts, comments, media) within the group is automatically deleted after 24 hours. The group itself remains, but the content vanishes. Imagine users creating groups for flash events, temporary project collaborations, or just sharing memes that are only funny for a day. Here are some considerations to guide our design: Use Cases: What are the primary use cases for Ephemeral Groups? Consider examples beyond those mentioned above. User Interface: How would users create and identify Ephemeral Groups within the existing Facebook app? How is it visually distinct? Data Storage: How would you efficiently store and automatically delete content to minimize storage costs and ensure compliance with the 24-hour expiration? Abuse Prevention: How do you prevent the misuse of Ephemeral Groups for sharing harmful or illegal content, given the disappearing nature of the data? Notifications: How would notifications work for Ephemeral Groups? Should users receive notifications for content that will disappear soon? Privacy: How would we make users aware of the ephemeral nature of the group and its content to manage their privacy expectations effectively? Scalability: How would this feature scale to handle potentially millions of Ephemeral Groups without impacting the performance of the overall Facebook platform? Walk me through your design proposal, addressing these considerations and any other relevant aspects you believe are important.

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Tell me about a time you had a conflict with a colleague. What was the nature of the conflict, and how did you approach resolving it? What was the outcome, and what did you learn from the experience? For example, perhaps you disagreed on the best approach to a technical problem, or maybe there was a misunderstanding about responsibilities. How did you communicate your perspective, and how did you listen to theirs? What steps did you take to find a mutually agreeable solution? Did you involve a mediator or supervisor, or were you able to resolve it yourselves? What were the key takeaways from that situation, and how have you applied those lessons to future collaborations? It is important to show that you can handle conflict well.