Interview Questions
Practice the exact questions companies are asking right now.
Implement an in-memory database with TTL and backup
In-Memory Database (Levels 1–4: TTL and Backup/Restore) Implement an in-memory database that stores records identified by a string key. Each record co...
Explain KV cache in Transformer inference
Question In Transformer-based language model inference, what is a key-value (KV) cache? Explain: - What gets cached (tensors, shapes at a high level) ...
Implement an in-memory file system
Implement an in-memory file system supporting basic directory and file operations. You must support the following methods (names are illustrative; any...
Explain container image flow in CI/CD
Scenario Walk through what happens in a typical CI/CD pipeline that builds and deploys a containerized service. Questions 1. During CI, how is a conta...
Retrieve First Active and Last Inactive Dates per User
Given a table activity that tracks user activities, write a SQL query to retrieve the first active date and last inactive date for each user. Table Sc...
Handle value conflicts and disagreeing with leadership
Behavioral / Values prompts Answer the following with specific examples (use the STAR method): 1. Have you ever made a decision that was “politically ...
Explain virtual machines and concurrency basics
Topics Answer at a senior-engineer depth. Use diagrams or step-by-step reasoning as needed. 1) Virtual machines (VMs) - What is a VM and what problem ...
Design a RAG system with evaluation
Scenario You are asked to design a Retrieval-Augmented Generation (RAG) system that answers user questions using a private corpus (e.g., internal docs...
Validate a JSON-like string
Problem You are given a string s that is intended to be a JSON text. Implement a function isValidJsonStructure(s) -> bool that checks structural valid...
Find path in implicit Fibonacci tree
You are given a special family of binary trees called Fibonacci trees. The k‑th order Fibonacci tree T(k) is defined recursively: - T(1) is a single n...
Implement an in-memory SQL-like table
Problem Implement a simple in-memory database for one table. All values are strings. Each row is identified by a rowKey (string). Each row contains co...
Maximize non-adjacent sum on an N-ary tree
You are given an N-ary tree (each node may have 0..k children). Each node contains an integer value (can be 0 or positive). You want to select a set o...
Design a compliant multi-tenant analytics platform
Prompt Design a multi-tenant data analysis platform for government and enterprise customers. The interviewer emphasizes that the key challenge is not ...
Compute courier pay and implement load balancing
Problem 1: Compute courier (delivery driver) pay You are given a sequence of delivery-related events for a courier during a day. Your task is to compu...
Implement toy-language types and generic substitution
Problem: Toy Language Type System (Printing + Generic Resolution) You are implementing a small type system for a custom “Toy Language”. Types can be: ...
Implement credit ledger with out-of-order timestamps
Problem You are implementing a GPU credit ledger that supports adding credits, charging credits, and querying balances. Requests can arrive in any tim...
Design a payment processing system
Scenario Design a backend payment system for an online product that supports: - One-time charges and refunds. - Idempotent payment APIs (clients may r...
Calculate transaction fees from CSV records
You are given a CSV-like multi-line string representing transactions with columns: id,reference,amount,currency,date,merchant_id,buyer_country,transac...
Determine order of alien alphabet
You are given a list of words sorted in lexicographic order according to an unknown ("alien") alphabet. Task Return one valid ordering of the unique c...
Compute minimum passes over permutation
Question You are given an array shelf representing a permutation of the integers 1..n. Starting with target = 1, you repeatedly scan the array left-to...