DevOps Engineer III, Amazon Pay

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 explore a scenario involving data transformation. Imagine you're receiving a stream of customer data from various sources. This data includes customer IDs, names, email addresses, and purchase histories. However, the data is inconsistent: some sources use different formats for dates, some have missing fields, and others use abbreviations for states. Your task is to design a robust and efficient system to clean and transform this data into a consistent format suitable for analysis. Specifically: Data Cleaning: How would you handle missing values, inconsistent date formats (e.g., MM/DD/YYYY vs. YYYY-MM-DD), and variations in state abbreviations (e.g., CA vs. California)? Provide code examples (Python is preferred) demonstrating how you would address these issues. Data Transformation: How would you transform the data to ensure consistency? For example, you might need to convert all dates to a standard format, expand state abbreviations to their full names, and ensure all customer IDs are in a uniform format. Scalability: How would you design the system to handle a large volume of data (e.g., millions of records per day)? Consider the technologies and architectures you would use to ensure scalability and performance. Think about potential bottlenecks and how to address them. Error Handling: Describe how you would implement error handling and logging to identify and address data quality issues. What metrics would you track to monitor the quality of the transformed data? For instance, suppose you receive the following data snippets: Source 1: {customer_id: 123, name: Alice, email: alice@example.com, purchase_date: 01/01/2023, state: CA} Source 2: {CustomerID: 456, Name: Bob, Email: bob@example.com, PurchaseDate: 2023-01-01, State: California} How would your system handle these variations and transform them into a unified format like this: {customer_id: 123, name: Alice, email: alice@example.com, purchase_date: 2023-01-01, state: California}

Amazon

Tell me about yourself. To help me understand your background, please structure your response by including the following: A brief overview of your educational background: Where did you go to school, what did you study, and what were your key areas of focus or specializations? A summary of your professional experience: Walk me through your previous roles, highlighting the companies you worked for, your responsibilities, and the significant projects you contributed to. Be sure to mention any accomplishments or quantifiable results you achieved. Skills and areas of expertise: What are your strongest technical skills and areas of expertise? Provide specific examples of how you've applied these skills in previous projects or roles. For instance, if you're proficient in Python, describe a project where you used Python to solve a complex problem. Your motivations and interests: What are you passionate about in the field of technology, and what motivates you to pursue a career in this area? What specific aspects of software engineering or your chosen field do you find most exciting or rewarding? Your career goals: Where do you see yourself in the next 3-5 years? What are your short-term and long-term career aspirations, and how does this role align with your overall goals? Are you looking to specialize in a particular area, take on leadership responsibilities, or make a significant impact in a specific industry? By providing this structured overview, I hope to gain a better understanding of your background, skills, and aspirations, and how they align with the goals and requirements of this position.