BT Business Security Engineer Interview Questions and Answers

Program to reverse an integer

• Convert the integer to a string

• Reverse the string

• Convert the reversed string back to an integer

I have worked on various projects including a web application for inventory management and a mobile app for task tracking.

• Developed a web application using React for inventory management, allowing users to track stock levels and generate reports.

• Created a mobile app using Flutter for task tracking, enabling users to create, assign, and track tasks in real-time.

• Collaborated with a team of developers to integrate APIs an...read more

Data structures are fundamental concepts in software engineering that organize and store data efficiently.

• Arrays: Simple and efficient for storing and accessing elements.

• Linked Lists: Dynamic and flexible, efficient for insertion and deletion.

• Stacks: LIFO structure, useful for managing function calls and undo operations.

• Queues: FIFO structure, ideal for managing tasks and scheduling.

• Trees: Hierarchical structure, used ...read more

The difference is that 'int arr[5]' creates an array on the stack, while 'malloc(5*sizeof(int))' allocates memory on the heap.

• int arr[5] creates an array of 5 integers on the stack, which is a fixed-size memory allocation.

• malloc(5*sizeof(int)) dynamically allocates memory on the heap, allowing for variable-size memory allocation.

• The memory allocated with malloc must be explicitly freed with free() to avoid memory leaks...read more

Entering a URL in the browser triggers a series of events to retrieve and display the requested webpage.

• The browser checks the cache for a previously stored copy of the webpage

• If not found, the browser sends a request to the DNS server to resolve the domain name to an IP address

• The browser then sends a request to the web server at the IP address for the webpage

• The web server responds with the requested webpage

• The brows...read more

MAC addresses are required for identifying devices on a local network, while IP addresses are used for identifying devices on a global network.

• MAC addresses are used for communication within a local network

• IP addresses are used for communication across different networks

• MAC addresses are assigned by the manufacturer and cannot be changed

• IP addresses can be assigned dynamically or statically

• MAC addresses are used in the...read more

An ArrayList is a dynamic array in Java that can grow or shrink in size during runtime.

• ArrayList is a class in Java's Collection framework.

• It implements the List interface and allows duplicate elements.

• Elements can be added or removed using methods like add(), remove(), etc.

• It can also be sorted using the sort() method.

• Example: ArrayList names = new ArrayList<>();

• names.add("John"); names.add("Mary"); names.remove(0);

Java is not a pure OO language due to primitive types not being objects.

• Primitive types like int, boolean, etc. are not objects in Java

• They do not have methods or inheritance like objects do

• This violates the principle of everything being an object in pure OO languages

• Wrapper classes like Integer, Boolean, etc. were introduced to provide object-like behavior for primitives

Inheritance is a way to create new classes based on existing ones. Abstraction is a way to hide implementation details.

• Inheritance allows a subclass to inherit properties and methods from a superclass.

• Abstraction allows a class to provide a simplified interface to its users while hiding its implementation details.

• For example, a Car class can inherit properties and methods from a Vehicle class, while also implementing i...read more

I bring innovative problem-solving skills, a collaborative mindset, and a passion for cutting-edge technology to Cisco.

• Proven experience in developing scalable software solutions, such as a cloud-based application that improved user engagement by 30%.

• Strong collaboration skills demonstrated through successful cross-functional projects, leading to a 20% reduction in development time.

• Passion for continuous learning, evid...read more

No, as a software engineer, you may not have the necessary experience or skills to work as an IT manager.

• Software engineers typically focus on coding and technical aspects, while IT managers are responsible for overseeing projects, teams, and budgets.

• IT managers need strong leadership, communication, and decision-making skills, which may not be the primary focus of a software engineer.

• Consider gaining experience in pro...read more

A router is needed to connect two computers in different networks or to share internet connection.

• When two computers are in different networks, a router is needed to connect them.

• A router can also be used to share internet connection between multiple devices.

• Routers can provide additional security features like firewall and VPN.

• Examples of routers include Cisco, Netgear, and TP-Link.

IPv4 has 32 bits and IPv6 has 128 bits.

• IPv4 addresses are in the format of xxx.xxx.xxx.xxx where each xxx is an 8-bit number.

• IPv6 addresses are in the format of xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx where each xxxx is a 16-bit number.

• IPv6 addresses allow for a much larger number of unique addresses than IPv4.

IPv6 is needed due to the exhaustion of IPv4 addresses and the need for more unique IP addresses.

• IPv6 provides a significantly larger address space compared to IPv4.

• It allows for the allocation of unique IP addresses to every device connected to the internet.

• IPv6 supports improved security features and better network performance.

• It enables the growth of Internet of Things (IoT) devices and services.

• Transitioning to IPv...read more

A /24 address can have 256 clients. Network address is the first IP and broadcast address is the last IP.

• A /24 address has 256 IP addresses

• The network address is the first IP in the range

• The broadcast address is the last IP in the range

Anycast, unicast, and multicast are different ways of routing network traffic.

• Unicast is one-to-one communication between a sender and a receiver.

• Anycast is one-to-nearest communication where the sender sends a message to the nearest receiver.

• Multicast is one-to-many communication where the sender sends a message to a group of receivers.

• Anycast is used for load balancing and finding the nearest server.

• Unicast is used f...read more

Virtual memory is a memory management technique that allows a computer to use more memory than physically available.

• Virtual memory is created by using hard disk space as an extension of RAM.

• It allows running more programs than the physical memory can handle.

• The size of virtual memory is typically larger than the size of main memory.

• Virtual memory is divided into pages, which are swapped in and out of main memory as nee...read more

I rate myself 8 in C and 7 in web technologies.

• I have extensive experience in C programming and have worked on multiple projects using it.

• In web technologies, I have a good understanding of HTML, CSS, and JavaScript, but there is always room for improvement.

• I am constantly learning and improving my skills in both areas.