Software Development Engineer, Amazon Connect Contact Lens

Amazon

Implement a Stack data structure using one or more Queues. Your stack should support the standard push, pop, top (peek), and empty operations. push(x):** Adds element x to the top of the stack. pop():** Removes the element on the top of the stack and returns it. top():** Returns the element on the top of the stack without removing it. empty():** Returns whether the stack is empty. For example, consider the following sequence of operations: push(1) push(2) top() // returns 2 pop() // returns 2 empty() // returns false Explain your approach clearly, focusing on how you would use queue operations (enqueue and dequeue) to achieve stack-like behavior. Discuss the time complexity of each operation in your implementation. Consider edge cases and potential optimizations.

Amazon

Let's design a turnstile. A turnstile is a type of gate which allows one person to pass at a time. Consider a turnstile at a subway station. There are two panels that rotate to allow a single person passage. The turnstile has two states, Locked and Unlocked, and the customer can either Push the turnstile or Insert a token/card. Here is the state transition table: | Event | Current State | Action | Next State | | :----- | :------------ | :------------- | :--------- | | Push | Locked | | Locked | | Token | Locked | Unlock | Unlocked | | Push | Unlocked | Pass through | Locked | | Token | Unlocked | (discarded) | Unlocked | Requirements: Model the state and behavior of a simple turnstile. Implement two methods: insert_token() push() Consider edge cases and error handling. What happens if someone tries to push without inserting a token? What happens if the system malfunctions? Example: turnstile = Turnstile() print(turnstile.state) # Output: Locked turnstile.push() print(turnstile.state) # Output: Locked turnstile.insert_token() print(turnstile.state) # Output: Unlocked turnstile.push() print(turnstile.state) # Output: Locked How would you approach this design and implementation, keeping in mind scalability, maintainability, and potential future extensions such as different types of tokens or remote unlocking?

Amazon

Why do you want to work at Amazon? To provide a comprehensive answer, consider the following aspects: Amazon's Mission and Values: How do Amazon's core values, such as customer obsession, innovation, bias for action, and ownership, resonate with your personal and professional values? Provide specific examples of how you've demonstrated similar values in your previous experiences. For instance, can you describe a situation where you went above and beyond to satisfy a customer, or when you took initiative to implement a novel solution to a challenging problem? Amazon's Culture of Innovation: Amazon is renowned for its innovative culture and willingness to experiment. How does this environment appeal to you? Are there any specific Amazon products, services, or initiatives that you find particularly inspiring or exciting? Perhaps you're impressed by Amazon Web Services (AWS), Amazon's foray into artificial intelligence with Alexa, or their advancements in logistics and delivery. Explain why these innovations capture your interest and how you believe you could contribute to future innovation at Amazon. Growth and Learning Opportunities: Amazon offers a wide range of opportunities for professional growth and development. What specific roles or career paths within Amazon are you interested in exploring, and why? Have you researched Amazon's internal training programs or mentorship opportunities? Discuss how you envision leveraging these resources to expand your skillset and advance your career within the company. For example, are you interested in moving into a leadership role, specializing in a particular technology, or working on a global scale? Your Skills and Experience: How do your skills and experience align with Amazon's needs and priorities? Identify specific projects or accomplishments from your past that demonstrate your ability to succeed in a fast-paced, demanding environment. Highlight any experience you have with technologies or methodologies that are relevant to Amazon's business, such as cloud computing, data analysis, machine learning, or agile development. Be prepared to discuss how your unique skills and experiences can contribute to Amazon's continued success. Can you quantify your accomplishments with metrics? Company Impact: What excites you about the potential to contribute to Amazon's impact on customers and the world? Consider how Amazon's products and services have transformed industries and improved people's lives. Are you drawn to the scale and scope of Amazon's operations, or the opportunity to work on projects that have a global reach? Express your enthusiasm for being part of a company that is constantly pushing boundaries and shaping the future.