Perfios Software Solutions Technical Lead Interview Questions and Answers

Hoisting is a behavior in JavaScript where variable and function declarations are moved to the top of their containing scope during compilation.

• Variable declarations are hoisted to the top of their scope, but not their assignments.

• Function declarations are fully hoisted, meaning they can be called before they are declared.

• Hoisting can lead to unexpected behavior if not understood properly.

Function currying is a technique in functional programming where a function with multiple arguments is transformed into a sequence of nested functions, each taking a single argument.

• Currying allows partial application of a function, where some of the arguments are fixed and the rest are left to be supplied later.

• It helps in creating reusable functions and improving code readability.

• Example: const add = (a) => (b) => a ...read more

Load balancers distribute incoming network traffic across multiple servers to ensure no single server is overwhelmed.

• Load balancers monitor the health of servers and distribute traffic based on predefined algorithms.

• They can be hardware-based or software-based.

• Common algorithms used by load balancers include round-robin, least connections, and IP hash.

• Load balancers can improve reliability and scalability of a website ...read more

The Two Sum problem involves finding two numbers in an array that add up to a target value.

• Iterate through the array and store the difference between the target and current element in a hashmap.

• Check if the current element exists in the hashmap, if yes, return the indices of the current element and the stored difference.

• Time complexity of O(n) can be achieved by using a hashmap to store elements and their indices.

Generate the first 50 prime numbers

• Start with the first prime number, 2

• Use a loop to check for prime numbers by dividing each number by all numbers less than it

• Keep track of the prime numbers found until you have 50