Arista Networks Interview Questions and Answers

Q1. C++ Pointer, address debugging question
Ans. 
Understanding C++ pointers and address debugging is crucial for effective memory management and error resolution.
• Pointers store memory addresses, allowing direct access to variables.

• Example: int* ptr = &var; // ptr holds the address of var.

• Dereferencing a pointer: *ptr gives the value at the address stored in ptr.

• Pointer arithmetic: ptr++ moves the pointer to the next memory location.

• Null pointers: Always initializ...read more
Answered by AI
Add your answer
Q2. Internal working of Hashmap in c C++ debugging the code
Ans. 
Hashmap in C/C++ stores key-value pairs using a hash function for fast retrieval.
• Hashmap uses a hash function to map keys to indices in an array.

• Collision handling is done using techniques like chaining or open addressing.

• Hashmap allows for fast insertion, deletion, and lookup of key-value pairs.

• Example: std::unordered_map in C++ implements a hashmap.

• Debugging hashmap code involves checking hash function, collision res...read more
Answered by AI
Add your answer

Q1. Trie based question
Add your answer
Q2. Design LRU cache
Ans. 
Design a data structure for LRU cache with get and put operations, evicting least recently used item when capacity is reached.
• Implement a doubly linked list to keep track of the order of keys based on their usage

• Use a hashmap to store key-value pairs for quick access

• Update the order of keys in the linked list when a key is accessed or inserted

• Evict the least recently used item when the cache reaches its capacity
Answered by AI
Add your answer

Q1. Unique ID generator
Ans. 
A unique ID generator creates distinct identifiers for entities, ensuring no duplicates across a system.
• Use UUIDs (Universally Unique Identifiers) for global uniqueness. Example: '550e8400-e29b-41d4-a716-446655440000'.

• Timestamp-based IDs can ensure uniqueness over time. Example: '20231005123000' for a timestamp.

• Combining user-specific data with random elements can create unique IDs. Example: 'user123-abc456'.

• Consider u...read more
Answered by AI
Add your answer
Q2. Project related questions
Add your answer

Q1. Operating systems, DBMS
Add your answer
Q2. Few question on projects from my previous company
Add your answer

Javascript concepts. Polyfill for debounce. Event loop. Questions based on your resume.

Q1. Design a ticket booking platform(Core problem: How would you prevent concurrent ticket booking by multiple users)
Ans. 
Implement session locking to prevent concurrent ticket booking by multiple users.
• Implement session locking mechanism to ensure only one user can book tickets at a time.

• Use a unique session ID for each user to track their booking process.

• Lock the session when a user starts booking tickets and release the lock once the booking is completed.

• Display a message to other users trying to book tickets if the session is already ...read more
Answered by AI
Add your answer
Q2. Questions from resume(The entire interview went on for 2 hours)
Add your answer

Q1. This was the final round(on-site) and was based on Architecture + cultural fit, conducted by one of their Directors / Associate Director. Was asked questions like reasons for switch, expectation in Arista,...read more
Add your answer
Q2. In a todo application a user's data is supposed to be synced in multiple devices. When there is a change made in the todo list in one device, the other device's UI needs to update without refresh. How woul...read more
Ans. 
Real-time synchronization of todo list across multiple devices using short polling and web sockets.
• Implement short polling to regularly check for updates on the server and update the UI accordingly.

• Use web sockets for real-time communication between devices to instantly push updates to all connected clients.

• Maintain a centralized database to store and retrieve the todo list data for all devices.

• Utilize a messaging queu...read more
Answered by AI
Add your answer
Q3. Pick one of your projects from your resume and explain.
Ans. 
Developed a responsive e-commerce website using React and Redux
• Utilized React for building the user interface

• Implemented Redux for managing the application state

• Designed a responsive layout for optimal viewing on different devices
Answered by AI
Add your answer

Q1. Explain the in detail about the project worked in your previous company??
Add your answer
Q2. Explain the packet format of frame, ARP, IP, OSPF, BGP, MPLS
Ans. 
Overview of packet formats for various network protocols including ARP, IP, OSPF, BGP, and MPLS.
• ARP (Address Resolution Protocol): Used to map IP addresses to MAC addresses. Packet includes hardware type, protocol type, hardware size, protocol size, opcode, sender MAC, sender IP, target MAC, target IP.

• IP (Internet Protocol): Responsible for addressing and routing packets. IPv4 header includes version, header length, ty...read more
Answered by AI
Add your answer

Q1. Tell me about your previous company role ?
Add your answer
Q2. Willing to join Arista ?
Ans. 
Yes, I am willing to join Arista as a Software Engineer.
• I am excited about the opportunity to work at Arista and contribute to their innovative projects.

• I have researched the company and believe that my skills align well with their values and goals.

• I am confident that I can make a positive impact on the team and help drive success at Arista.
Answered by AI
Add your answer

One Hr interview with 3-4 coding questions on strings,array and linked list

Q1. A string contains parenthesis, curly brackets and square brackets. Check if the string is valid or not.
Ans. 
Check if a string containing parenthesis, curly brackets, and square brackets is valid.
• Use a stack to keep track of opening brackets

• Pop from stack when encountering a closing bracket, ensuring it matches the corresponding opening bracket

• Return false if stack is not empty at the end
Answered by AI
Add your answer