Software Developer 4

Oracle

Simulate a multithreaded producer-consumer problem using Java threads and semaphores. Implement a producer that generates items and adds them to a shared buffer, and a consumer that retrieves and processes items from the same buffer. Synchronize access to the buffer using semaphores to prevent race conditions and ensure that the producer doesn't add items to a full buffer and the consumer doesn't try to retrieve items from an empty buffer. Specifically: Define a shared buffer: This could be an ArrayList or any other suitable data structure with a fixed capacity. Implement the Producer: The producer should generate a series of items (e.g., integers) and attempt to add them to the buffer. Before adding an item, it must acquire a semaphore that represents available space in the buffer. If no space is available, the producer should wait. After adding an item, it should release a semaphore that represents available items in the buffer. Implement the Consumer: The consumer should attempt to retrieve and process items from the buffer. Before retrieving an item, it must acquire a semaphore that represents available items in the buffer. If no items are available, the consumer should wait. After retrieving an item, it should release a semaphore that represents available space in the buffer. Synchronization: Use semaphores to handle synchronization. One semaphore should track the number of empty slots in the buffer, and another should track the number of filled slots. Example Scenario: Create a buffer with a capacity of 5. Have the producer generate 10 items and the consumer consume 10 items. Print messages indicating when the producer adds an item and when the consumer consumes an item. Ensure that the producer and consumer run concurrently and that no items are lost or duplicated. Your solution should demonstrate: Proper use of Java threads. Correct semaphore usage for synchronization. Prevention of race conditions. Handling of full and empty buffer conditions.

Oracle

Let's design a system for deleting all user data in a large-scale application. Consider the following requirements: Compliance: The system must adhere to data privacy regulations (e.g., GDPR, CCPA) regarding the right to be forgotten. This means all personal data must be permanently and irrevocably deleted. Data Scope: User data is distributed across various databases (e.g., relational, NoSQL), object storage, and potentially third-party services. Examples include: User profiles in a relational database (name, email, address). User-generated content (photos, videos) in object storage. User activity logs in a NoSQL database. User data cached in a Redis cluster. User accounts on integrated third-party services (e.g., payment processors, social media platforms). Performance: The deletion process should be efficient and not significantly impact the performance of other system operations. Consider the impact on databases and other services during peak hours. Consistency: The system must ensure data consistency. For example, if a user has dependencies on other data (e.g., a user is an administrator of a group), these dependencies must be handled correctly (e.g., reassigning ownership, deleting dependent data). Auditability: All deletion requests and actions must be logged for auditing and compliance purposes. The logs should record who requested the deletion, when it was requested, what data was deleted, and the outcome of the deletion process. Error Handling: The system should gracefully handle errors and retries. If a deletion fails in one component, it should be retried or rolled back appropriately, and alerts should be generated. Scalability: The system must be able to handle a large number of deletion requests concurrently. Data Minimization: Before initiating the deletion process, verify if data minimization techniques can be applied instead of complete deletion, such as anonymization or pseudonymization, especially for datasets needed for analytical purposes. Given these requirements, how would you design a system to handle user data deletion requests? Discuss the architecture, components, data flow, and any trade-offs you would consider.

Oracle

Okay, let's imagine we're at a career fair, and you have about two minutes to introduce yourself to a recruiter. Keeping that timeframe in mind, could you provide a concise overview of your background, skills, and career aspirations? Think of it as your elevator pitch. For example, you might highlight your key accomplishments from previous roles, discuss your proficiency in specific programming languages or technologies relevant to the target position, and briefly touch upon your career goals and what you're hoping to achieve in your next role. What makes you a great candidate?