AppFolio Software Engineer II Interview Questions and Answers

Design a system for managing car parking.

• Determine the size and layout of the parking lot.

• Decide on the type of parking system (e.g. self-parking, valet).

• Implement a ticketing system for tracking cars and payments.

• Use sensors or cameras to monitor parking spaces.

• Integrate with a payment gateway for online payments.

• Provide real-time information on available parking spaces.

• Consider implementing a loyalty program for freq

Designing a system for an elevator

• Identify the requirements and constraints

• Determine the number of floors and elevators needed

• Choose the elevator algorithm (e.g. FCFS, SCAN, LOOK)

• Design the elevator controller

• Consider safety features (e.g. emergency stop, overload protection)

• Include user interface (e.g. buttons, displays)

• Consider maintenance and repair

• Test and optimize the system

A photo-sharing app system design

• Use a scalable architecture to handle large amounts of data

• Implement a secure authentication and authorization system

• Utilize a content delivery network (CDN) for fast image loading

• Allow users to tag and categorize photos for easy search and discovery

• Implement a notification system for likes, comments, and new followers

Python has several built-in datatypes including int, float, bool, str, list, tuple, set, and dict.

• int - represents integers

• float - represents floating-point numbers

• bool - represents boolean values True and False

• str - represents strings

• list - represents ordered sequences of values

• tuple - represents ordered, immutable sequences of values

• set - represents unordered collections of unique values

• dict - represents unordered co

Flask is a micro web framework while Django is a full-stack web framework.

• Flask is lightweight and flexible, allowing developers to choose their own libraries and tools.

• Django is a batteries-included framework with built-in ORM, admin interface, and authentication system.

• Flask is ideal for small to medium-sized projects, while Django is better suited for larger, more complex projects.

• Flask has a smaller learning curve ...read more

Flask is lightweight and good for small projects, while Django is more robust and suitable for larger projects.

• Flask is good for small projects with simple requirements

• Django is more suitable for larger projects with complex requirements

• Flask is lightweight and flexible, allowing for more customization

• Django has a lot of built-in features and is more opinionated

• Flask is better for RESTful APIs and microservices

• Django i...read more

Decorators are functions that modify the behavior of other functions or classes without changing their source code.

• Decorators are denoted by the @ symbol in Python.

• They can be used to add functionality to a function or class, such as logging or timing.

• Decorators can also be used to modify the behavior of a function or class, such as adding caching or memoization.

• Decorators can be chained together to apply multiple modi

Generators are functions that can be paused and resumed, allowing for lazy evaluation of data.

• Generators use the yield keyword to pause execution and return a value.

• They can be used to generate an infinite sequence of values.

• Generators are memory efficient as they only generate values when needed.

• They are commonly used in data processing and asynchronous programming.

range and xrange are used to generate a sequence of numbers in Python.

• range returns a list of numbers while xrange returns an iterator object.

• range is memory-intensive while xrange is memory-efficient.

• range is used in Python 3 while xrange is used in Python 2.

• range can take three arguments: start, stop, and step while xrange can take two arguments: start and stop.