Citicorp Senior Engineer Interview Questions and Answers

Use two threads to print odd and even numbers in sync

• Create two threads, one for printing odd numbers and one for printing even numbers

• Use synchronization mechanisms like mutex or semaphore to ensure output is in sync

• Example: Thread 1 prints odd numbers (1, 3, 5, ...) and Thread 2 prints even numbers (2, 4, 6, ...)

Find the largest common prefix among an array of strings.

• Iterate through the characters of the first string and compare with the corresponding characters of other strings.

• Stop when a mismatch is found or when reaching the end of any string.

• Return the prefix found so far.

Saga pattern is a design pattern used in microservices architecture to manage distributed transactions.

• Saga pattern breaks down a transaction into a series of smaller, independent steps.

• Each step in the saga is a separate transaction that can be rolled back if needed.

• If one step fails, compensating transactions can be executed to undo the changes made by previous steps.

• Saga pattern helps maintain data consistency in a ...read more

Hash map and hash set are data structures that use hashing to store key-value pairs and unique values respectively.

• Hash map uses key-value pairs where keys are hashed to find the corresponding value

• Hash set stores unique values using hashing to quickly check for duplicates

• Example: HashMap<String, Integer> map = new HashMap<>(); HashSet<Integer> set = new HashSet<>();

Singleton pattern ensures a class has only one instance and provides a global point of access to it.

• Singleton pattern involves a private constructor, a static method to access the instance, and a static variable to hold the instance.

• To break the singleton pattern, one can use reflection to access the private constructor and create multiple instances.

• Another way to break the singleton pattern is by using serialization a...read more

Negotiating a package involves discussing salary, benefits, and other perks to reach a mutually beneficial agreement.

• Research industry standards for salary and benefits to set realistic expectations.

• Prepare to articulate your value, citing specific achievements and skills that justify your request.

• Consider the entire compensation package, including bonuses, stock options, and work-life balance.

• Be open to negotiation; i...read more

I am excited about the innovative projects and collaborative team environment at this company.

• Opportunity to work on cutting-edge projects

• Collaborative team environment

• Strong company culture and values

• Room for growth and advancement

• Positive reputation in the industry

Bigdata systems architecture involves distributed storage, processing, and analysis of large volumes of data.

• Utilize distributed file systems like HDFS for storage

• Use parallel processing frameworks like Apache Spark or Hadoop for data processing

• Implement data pipelines for ETL processes

• Leverage NoSQL databases like Cassandra or MongoDB for real-time data querying

• Consider data partitioning and replication for fault tole...read more

Big data system distribution for storage and compute involves partitioning data across multiple nodes for efficient processing.

• Data is partitioned across multiple nodes to distribute storage and processing load.

• Hadoop Distributed File System (HDFS) is commonly used for storage distribution.

• Apache Spark utilizes a cluster computing framework for distributed computing.

• Data locality is important to minimize data transfer ...read more

Design a system similar to YouTube for video sharing and streaming

• Implement user authentication and authorization for uploading and viewing videos

• Create a database to store video metadata, user information, and comments

• Develop a recommendation algorithm based on user preferences and viewing history

• Utilize a content delivery network (CDN) for efficient video streaming

• Include features like video monetization, live stream...read more

Discussing a project involves outlining objectives, challenges, and outcomes to showcase engineering skills and teamwork.

• Define project goals: For example, improving system efficiency by 20%.

• Identify challenges faced: Such as tight deadlines or resource limitations.

• Describe your role: Explain your contributions, like leading a team or developing a key feature.

• Highlight outcomes: Share metrics, like increased user satis...read more

Kafka is a distributed streaming platform used for building real-time data pipelines and streaming applications.

• Kafka uses a publish-subscribe model for messaging, allowing multiple producers and consumers.

• Topics in Kafka are partitioned for scalability; for example, a topic with 3 partitions can handle 3 consumers simultaneously.

• Kafka ensures message durability through replication; if one broker fails, others can stil...read more