IBM Interview Questions

IBM is one of the biggest technology companies in the world, and they are leaders in AI, cloud computing, and enterprise solutions. Their interview process is quite rigorous, and it includes technical skills as well as problem-solving skills. If you are planning to work in a technical position at IBM, then it is important to be well-equipped to face questions on algorithms, programming languages, databases, and system design. Read on to discover some of the most common questions that are made in IBM technical interviews and the concepts and approaches that you need to master to answer them successfully. Read on to find out how to improve your self-esteem and improve your chances of getting the job of your dreams at IBM.

Table of Contents:

• IBM Interview Process
• IBM Interview Questions For Freshers
• IBM Technical Interview Questions
• IBM Manager Round Interview Questions
• Conclusion

IBM Interview Process

IBM’s recruitment process includes 3 rounds, where in each round the candidates get eliminated.

1. 1. Online Written Test
   2. Group Discussion Round
   3. Interview Round (Technical + HR)

Let’s discuss each round.

1. Online Written Test

This is the first round, which has two sections that are coding tests and English language tests. You need to complete this written test in 65 minutes. In the coding section, there will be 2 questions with a time duration of 55 minutes. The English Language Test includes 10 questions with a time duration of 10 minutes.

2. Group Discussion Round

Once you clear the written test, you will receive an email from IBM inviting you to the GD round. In this round, the discussion can be related to abstract topics, social issues, and current affairs. Be confident while giving your opinion.

3. Interview Round

If you pass the GD round, you will be moved to the final round, which is the interview. This interview is also being conducted in two sections.

3.1 Technical Interview

This is the first interview round where the panelist is going to ask you questions related to your resume and your final year project. Here you can expect the questions that are related to the CS fundamental topics like DBMS, data structures, algorithms, operating systems, networking, OOPs, and a programming language that you know better.

3.2 HR Interview

After your technical interview, there will be an HR interview round where the recruiter will ask you about your personality, strengths, and confidence. They will also ask you what you know about IBM and about your job role.

IBM Interview Experience

A lot of candidates have shared their IBM interview experiences. Below are some important points that were common among every other candidate.

1. The technical interview revolves around the resume and the project on which you have worked. It is often focused on the final year project and other sections of the resume.
2. The HR interview mainly targets confidence and the ability to communicate.
3. A few candidates were inquired about their coding problem-solving strategies.
4. In the general discussion round, the candidates who could express their ideas and make relevant contributions were noticed more.

IBM Interview Process For Experienced

People who are considered for technical and experienced positions at IBM are evaluated on their skills and cultural fit within the company’s environment. Below are some pointers:

1. Application and Screening: Fill in your details at the IBM careers portal. Your resume will be scanned for keywords and relevant experience to determine if you qualify for the role.
2. Online Assessments: It is possible that you will be asked to take tests that evaluate your skills, problem-solving abilities, and your command of the English language.
3. Technical Interview: In this round, you will be tested for both theoretical and practical knowledge of your field as well as your coding accuracy. Be ready to present the projects you have worked on and other domains of your technical expertise.
4. Behavioral Interview: In this interview, HR assesses soft skills, work experience, leadership, and all the information collected during the interview to see if the candidate is a culture fit within IBM.
5. Decision: Once the interviews are completed, the panel convenes to deliberate. A successful candidate will be given an offer letter specifying the particulars of the role.

IBM Interview Questions For Freshers

1. What is Object-Oriented Programming (OOP)?

OOP is a programming language paradigm that is based on objects and classes. It facilitates code reuse and modularity through four main principles:

• Encapsulation (Data implementation is hidden).
• Abstraction (Some details are hidden).
• Inheritance (Another class’s properties are derived).
• Polymorphism (the same function name behaves differently).

2. What is SQL, and why is it used?

SQL (Structured Query Language) is used to create, update, delete, and query (retrieve) data from a relational database. All the operations are performed on tables, and they follow a structured format.

Key SQL Operations: 

1. DDL (Data Definition Language): It is used to define the database structure, like create, alter, and drop.
2. DML (Data Manipulation Language): It is used to change the data in the database, like insert, update, and delete.
3. DQL (Data Query Language): It is used to retrieve data from the database like select.
4. DCL (Data Control Language): It is used to control access, like grant and revoke.
5. TCL (Transaction Control Language): It is used to manage transactions like commit and rollback.

SQL is used in relational databases such as MySQL, PostgreSQL, and Microsoft SQL Server to maintain data accuracy and integrity.

3. What is the difference between HTTP and HTTPS?

HTTP is a communication protocol that is used in transferring data between web browsers and servers, but it is not secure. HTTPS is the encrypted version of HTTP, and it uses SSL/TLS encryption to secure the data transfer.

4. What is an IP address?

An Internet Protocol address (IP) is a specific form of identification assigned to any device connected to a network so that it can communicate over the Internet.

Two types:

• IPv4 (IPv4, Internet Protocol Version 4): The use of 32-bit addressing, for example, 168.1.1.
• IPv6 (IPv6, Internet Protocol Version 6): 128 bits for addressing, intended for more devices than IPv4,  2001:db8::ff00:42:8329.

5. What is garbage collection in Java?

Java has an automatic memory management process, Garbage Collection (GC), which identifies and removes unused objects from memory to free up space and avoid memory leaks. The Java Virtual Machine (JVM) handles GC, so there’s no need to manually memory deallocate, as in C or C++.

6. Explain the difference between GET and POST methods in HTTP.

The GET method is used to request data from the server. It carries data in the URL, which is visible and also has a size limit. GET is idempotent; if multiple requests are made, they will return the same response.

The POST request sends data to the server within the body of the request, thus more secure and capable of carrying more data than the GET request. POST is used in form submissions and is a non-idempotent request, which may result in different responses for subsequent requests.

7. What’s the difference between List and Tuple?

8. What is normalization in databases?

Normalization is the process of database organization to reduce redundancy and dependency by dividing large tables into smaller and easier-to-manage tables. The main objective is to check the data consistency.

The process is done in stages called normal forms (NF): In the first normal form (1NF), it is ensured that there are no repeating groups. The second Normal Form (2NF) removes partial dependency. The third Normal Form (3NF) eliminates transitive dependency. Other higher-normal forms, such as BCNF, are used to further enhance the structure of the database. However, since normalization enhances the data integrity, it at the same time may result in a decrease in performance due to the increased number of joins.

9. What are the various types of storage classes in C?

In C, storage classes are used to specify the lifetime, scope, and type of variables. Allocated on the stack is auto, the default for local variables. A register is a suggestion to store variables in CPU registers for quicker access but does not allow taking their address. The static class keeps a variable’s value across function calls and is used for both local and global variables, the memory being in the data segment. External variables are those that are shared between different files; they are declared in one file and defined in another. Every class impacts the visibility, memory usage, and behavior of variables within a program.

10. What is the difference between primary memory and secondary memory?

Primary Memory (RAM): The data storage device that holds data that is currently in use is volatile. It is fast but temporary; when the system is shut down, the data is gone.

Secondary Memory (HDD/SSD): The type of non-volatile memory used for the storage of data in the long term. It is slower than the primary memory but has more capacity.

Primary memory enhances the system’s performance, whereas secondary memory offers permanent storage of files and applications.

11. What is Variable Scope?

Variable scope means the part of the program where a variable is valid or available. It determines the access and duration of a variable across the different parts of the program.

There are several types of variable scope, which are described below:

• Local Scope: The variable is declared within a function or a block, e.g., a loop or if-else statement, and is only visible in that function or block. It comes into existence at the time of the function or block’s start and is released when the function or block is finished.
• Global Scope: A variable that is declared outside of any function is accessible to all parts of the program and can be used by any function in the program. Global variables have a long lifetime, being alive during the entire runtime of the program. Therefore, the use of global variables is generally avoided in favor of local variables for better modularity and readability.

12. What is the Singleton Design Pattern?

The Singleton Design Pattern ensures that a class has one and only one instance and provides a global point of access to that instance. It is commonly used for controlling the use of shared resources such as database connections or application configurations. The pattern prevents the instantiation of more than one object and guarantees that only one object is created during the lifetime of the application.

13. What is the use of the final keyword in Java?

The final keyword in Java is used to restrict modification.

• Final variables cannot be reassigned.
• Final methods cannot be overridden by subclasses.
• Final classes cannot be subclassed. It ensures immutability and security.

14. What is the difference between a compiler and an interpreter?

• Compiler: The program is translated fully into machine code by a compiler before execution, which makes execution very fast after compilation.
• Interpreter: During execution, an interpreter translates code line by line, but with immediate error feedback, which is slower.

Example: C++ is compiled, and Python is interpreted.

15. What is Dependency Injection?

Dependency Injection (DI) is a pattern where dependencies of an object are injected at runtime, as opposed to being hardcoded. It also makes testability better, reduces dependencies, and increases flexibility. They are used to automatically manage runtime object creation and injection without the use of frameworks, such as the Spring Framework. Unit testing is easier with DI and it enhances the coupling of loose components in applications.

IBM Technical Interview Questions

16. What is virtual memory in an operating system?

Virtual memory is an OS memory management strategy that uses disk space (swap space) to enlarge the size of RAM. Temporary data is moved from RAM to disk in order to run large programs or multiple processes. Paging (a method of dividing memory into fixed-size pages) and swapping (moving inactive data to disk) are used by virtual memory to space-bucket.  Without a paging table, the processor does not know the physical address of a virtual address, so it must first send a paging request to memory management units (MMUs).

17. What is the difference between a process and a thread?

A process is a self-contained execution entity that has its own memory and system resources and runs independently from other processes. Because they don’t share memory, processes can communicate only by using inter-process communication (IPC) mechanisms. The creation and context-switching of processes are more costly than those of lightweight processes because of the overhead incurred in allocating memory and managing resources. In contrast, a thread is a lighter-weight execution thread that runs within a process, and it shares the memory and resources of the process. It is fast to create and switch to threads, but it also means that communication is direct, boosting performance but also increasing the risk of data corruption through shared memory. While processes are very useful for running different apps, threads are more suitable for managing different tasks that are to be executed concurrently as part of the same program.

18. What is Process Scheduling?

Process scheduling is the process of managing the different processes by the operating system to be efficient. It determines what process should get the CPU and how long it should get it, to name fair resource allocation and optimal system performance. The queue of processes is managed by the scheduler, which selects processes and prioritizes them according to factors such as priority, execution time, and resource requirements.

19. What is a Deadlock in an Operating System?

An operating system deadlock is a situation where two or more processes are stuck in a circular wait, where they require a resource from the other process to continue execution. Since no process can continue, the system is said to have reached a state where it is unable to proceed and execution is halted indefinitely.

20. What is the difference between SQL and NoSQL databases?

SQL: Databases based on SQL are relational; they employ strictly structured tables, which are used for data storage in a predetermined schema. Each table is composed of rows and columns; key fields are primary keys for distinguishing each row and foreign keys for relating one or many tables. They guarantee the ACID properties (atomicity, consistency, isolation, durability) of data. SQL databases are well suited to any application that entails sophisticated queries, transactions, and strict data integrity requirements, including banking systems. Some of the popular examples of SQL databases are MySQL, PostgreSQL, and Oracle.

NoSQL: NoSQL databases are designed to handle unstructured or semistructured data and are not relational. They store data in flexible formats like key-value pairs, documents, graphs, or wide-column stores without having to define a schema for the data. NoSQL databases are scalable horizontally and are perfect for large applications with a mix of data types and high traffic because of this. Example: MongoDB, Cassandra

21. What is Docker?

Docker is an open-source product that implements the concepts of containers to automate the deployment of applications. A container is a package of an application with its dependencies that can be run in any environment. Docker provides portability, scalability, and efficiency in deployment and is thus a valuable tool for DevOps teams.

22. What are WebSockets?

WebSockets are a technology that allows for a single full-duplex connection between the client and the server to be established and kept alive for a long time. It helps in creating real-time, interactive applications like chat apps and data streaming. Web sockets are a two-way communication and may be more effective than HTTP polling for real-time applications. It begins with an HTTP handshake, but it speaks a different language after that.

23. Write a program to print all the anagrams together.

A simple way to approach this problem is using a hash table. The idea is to calculate a hash value for each word such that all anagrams will hash to the same value. A simple way of calculating the hash value could be to take the modulo sum of all the characters in the word.  However, there is a possibility that two non-anagram words may have the same hash value. To this end, we can compare the characters of each word directly, so that only words with the same characters are placed in the same group. Once the hash values are found, a hash table is populated such that each key is a unique hash value and its associated value is a list of words that hash to that key. The program can then iterate through the hash table and print the anagrams that are grouped together by their hash values.

24. What is Cloud Computing?

Cloud computing is the use of technology that makes it possible for users to access resources and other computing resources, such as servers, storage, databases, networking, and software, over the Internet rather than from their own local systems. It offers on-demand computing capacity, leading to scalability, flexibility, and cost efficiency.

25. What is load balancing?

Load balancing is the technique that is used to evenly distribute the network traffic across different servers to avoid overloading a single server. It enhances the performance, scalability, and dependability of web applications. Round-robin, least connections, and IP hash are algorithms that hardware or software load balancers can use to determine where to forward traffic.

26. What is Blockchain?

Blockchain is a kind of decentralized, distributed ledger technology that has the capacity to document transactions and share them across a network securely. Cryptographic hashing is used to guarantee the data integrity and near immutability of the data. Every transaction is packaged into a block, which is then connected to the preceding block, thereby forming a chain. Blockchain is the technology on which cryptocurrencies such as Bitcoin are based, and it has applications in safe smart contracts, the supply chain, and many other areas.

27. What is an API?

An API (Application Programming Interface) is a set of program interactions and procedures that allow the programming of different applications to communicate with each other. It defines the request and response methods of an application to interact with another external system.

Types of APIs:

• REST API: It uses HTTP methods and JSON for communication.
• SOAP API: It uses XML to exchange data, and it is common in enterprise environments.
• GraphQL: It is a query language that enables you to fetch specific data from the endpoints. The mentioned APIs are used for third-party service integration, database access, or cloud platform communication.

28. What is a circuit breaker pattern?

The circuit breaker design pattern is a failure-cascading control mechanism in a system. It is a watchdog that sits on top of an interface to an external service or a function, and if failures occur beyond a certain threshold, it trips, blocking any further attempts to call the function to give the system a chance to recover. It enhances the resilience and fault tolerance of the system by enabling the services to continue to work in a diminished capacity.

29. Explain OAuth.

OAuth is an open standard for authorization that provides a secure way to allow third parties to access resources without the use of credentials. Authorization is done using tokens and not passwords. OAuth enables users to allow an application to act on their behalf at another service (Google or Facebook, for example) without having to share their credentials. The token can be scoped to have limited rights (read-only) and can also expire.

30. What is the difference between Monolithic and Microservices architecture?

Monolithic architecture is building a single, unified application. It is relatively easy to build in the beginning and very difficult to scale and manage as it grows. The microservices architecture is an approach that divides an application into several small services. Each of the services is responsible for a particular business function, which increases the system’s scalability, autonomy, and robustness. CI/CD is easier, and fault isolation is better with microservices.

IBM Manager Round Interview Questions

31. How do you handle conflicts within your team?

I try to listen to both sides, understand their issues, and reach a possible compromise. When necessary, I interfere to clear up confusion and remind everyone about the team’s focus. Most importantly, I try to resolve the problem as fast as possible while ensuring that each side is able to work cordially.

32. Have you ever missed a deadline? What happened, and how did you fix it?

Yes, I can say that a project was delayed because some of the technical challenges were unexpected. In this situation, I contacted the stakeholders, informed them of the scenarios, and altered their expectations while helping my team fix the problem. We also updated our planning processes in case similar delays occur in the future.

33. How do you prioritize tasks when handling multiple projects?

I first determine which tasks need to be done first and those that are critical. After that, I create a plan by breaking these tasks into smaller chunks and assigning deadlines for each of them. I also try to increase efficiency by empowering work to other employees whenever I can. If there is a change in priorities, I shift my plans as needed.

34. If your team strongly disagrees with your decision, how do you handle it?

I listen to their arguments and appreciate their point of view. If the argument they put up makes sense, I try to tell them that I will review my decision. In case I still feel that I am correct, I make my decision sensible and try to convince them to agree with me.

35. How do you align with IBM’s core values?

IBM is known for innovation, trust, and teamwork, which is what I attempt to achieve in my work. I actively seek better choices, try to be as transparent as possible in my decisions, and have faith that collaboration is the key to success.

Conclusion

When Interviewing with IBM, make sure you polish topics such as Operating Systems, SQL, OOP, and Cloud Computing. As a fresh graduate or an applicant for a technical support or management position, Always make sure you practice coding challenges, revise important topics, and maintain a positive attitude during the interview. With effective communication and problem-solving abilities, you will be able to clarify your case.