Data Structures & Algorithms
This data structure uses FIFO (First In, First Out) ordering and is commonly used in BFS traversal.
What is a queue?
This is the main purpose of a load balancer in a distributed system.
What is the distribution of incoming traffic across multiple servers?
This HTTP method is idempotent and typically used to update a resource completely.
What is PUT?
This is a condition where two threads access shared data simultaneously and at least one modifies it.
What is a race condition?
This type of database is optimized for storing structured data with predefined schemas.
What is a relational database?
This is the average time complexity of searching in a balanced binary search tree.
What is O(log n)?
This database scaling strategy involves splitting data across multiple machines based on a key.
What is sharding?
This status code indicates a successful request with no response body.
What is 204 No Content?
This synchronization primitive allows only one thread to access a critical section at a time.
What is a Mutex (or a Lock)?
These words make up the acronym ACID.
What are Atomicity, Consistency, Isolation, Durability?
This algorithm efficiently finds the shortest path in a graph with non-negative edge weights.
What is Dijkstra’s Algorithm?
This consistency model ensures all users see the same data at the same time after a write.
What is a strong consistency model?
This is the key difference between REST and GraphQL in terms of data fetching.
What is REST uses fixed endpoints while GraphQL allows clients to request specific data?
This issue occurs when two or more threads are blocked forever waiting for each other’s resources.
What is a deadlock?
This index type is typically used to speed up range queries in databases.
What is the B-Tree Index?
This data structure allows O(1) average time complexity for insert, delete, and lookup, but may degrade with poor hashing.
What is a hash table?
This architectural pattern uses immutable data and appends changes as a sequence of events.
What is event sourcing?
This pattern helps ensure API reliability by preventing repeated execution of the same request.
What is the idempotency key pattern?
This concept allows multiple readers but only one writer to access a resource concurrently.
What is a read-write lock?
This is the trade-off described by the CAP theorem when a network partition occurs.
What is Consistency vs Availability?
This combination of data structures provides optimal performance in a system requiring frequent median retrieval from a dynamic dataset.
What is Two Heaps (max heap for lower half, min heap for upper half)?
In designing a globally distributed system like a social media feed, this technique helps reduce latency by serving data closer to users.
What is CDN (Content Delivery Network) + edge caching?
This technique prevents cascading failures in high-scale systems by stopping repeated attempts to access a failing service.
What is the circuit breaker pattern?
This concurrency model uses message passing instead of shared memory to avoid locking issues.
What is the actor model?
This technique improves write performance and scalability by sequentially logging writes before applying them to storage, used in systems like LSM trees.
What is Write-Ahead Logging (WAL)?