10+ Deqode Interview Questions and Answers

Technical interview questions for Associate Staff Engineer position

• To make an object thread-safe, use synchronization or use thread-safe data structures

• Immutable class is a class whose state cannot be modified after creation

• Java uses a mark-and-sweep algorithm for garbage collection

• To print the left view of a binary tree, perform a level order traversal and print the first node at each level

• Circuit breaker design pattern is used to prevent cascading failures in distributed sy...read more

Create a timer with start stop and reset buttons that can work automatically but also be manually controlled.

• Implement a timer function that starts counting when mounted

• Include start, stop, and reset buttons for manual control

• Allow the buttons to interfere with the automatic timer

• Use JavaScript to handle the timer functionality

Create a nested comment section with name, time, and comment for users to reply.

• Create a parent comment section with fields for name, time, and comment

• Allow users to reply to comments, with nested replies

• Display nested replies under the parent comment they are replying to

Flatten nested objects with simplified keys like person.name.firstName

• Iterate through the nested objects using recursion

• Concatenate the keys with a dot to create the simplified key

• Store the value of the nested key in the flattened object

Spark job optimisation techniques include partitioning, caching, and tuning resource allocation.

• Partitioning data to distribute workload evenly

• Caching intermediate results to avoid recomputation

• Tuning resource allocation like memory and CPU cores

• Using broadcast variables for small lookup tables

• Avoiding shuffling operations whenever possible

Isolation level determines how transactions interact with each other.

• Isolation level defines the degree of locking and visibility of data during a transaction.

• It affects the concurrency and consistency of the database.

• Examples of isolation levels are READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ, and SERIALIZABLE.

• Transaction propagation refers to the behavior of transactions when they are nested or called from other transactions.

Lazy loading is a technique used in Angular to load modules on demand instead of loading everything at once.

• Lazy loading helps to improve the performance of the application by reducing the initial load time.

• It allows the application to load only the required modules when they are needed.

• Lazy loading is achieved by using the loadChildren method in the routing configuration.

• Example: loadChildren: () => import('./lazy/lazy.module').then(m => m.LazyModule)

Introduction is the first part of a speech or presentation where the speaker grabs the audience's attention and sets the tone for the rest of the talk.

• Start with a hook to grab the audience's attention

• Introduce yourself and your topic

• Provide some background information or context

• Preview what you will be discussing in the main body of the speech

NoSQL databases are non-relational, flexible, and scalable, while SQL databases are relational and structured.

• NoSQL databases are schema-less, allowing for flexibility in data storage.

• SQL databases use structured query language for data manipulation.

• NoSQL databases are better suited for unstructured or semi-structured data.

• SQL databases are ideal for complex queries and transactions.

• Examples of NoSQL databases include MongoDB, Cassandra, and Redis.

• Examples of SQL databases in...read more