Top 30 Most Common Software Engineering Viva Questions You Should Prepare For
Written by
James Miller, Career Coach
Preparing for a software engineering viva is a critical step in securing your desired role. These interviews, often verbal examinations, delve deep into your theoretical knowledge, practical experience, and problem-solving abilities. Unlike standard coding challenges, software engineering viva questions assess your fundamental understanding of concepts, design choices, and how you articulate complex technical ideas. Mastering these questions demonstrates not just what you know, but how well you grasp the underlying principles of software development, system design, and algorithmic thinking. A strong performance in a viva session signals to interviewers that you have a solid foundation and the potential to grow within the team. This guide provides a comprehensive look at some of the most frequently asked software engineering viva questions, offering insights into why they are asked, how to approach them, and example answers to help you build confidence and ace your next interview. Covering topics from core programming concepts and data structures to software development methodologies and system architecture, this list is designed to give you a significant advantage in your preparation. Get ready to articulate your technical prowess and impress your interviewers with well-thought-out responses to these essential software engineering viva questions.
What Are software engineering viva questions?
Software engineering viva questions are essentially verbal technical interview questions. They differ from coding challenges or system design discussions by focusing more on theoretical understanding, fundamental principles, and the ability to explain concepts clearly. These questions cover a broad spectrum of topics relevant to a software engineer's role, including data structures, algorithms, operating systems, databases, networking basics, programming paradigms, software development lifecycle, design patterns, and object-oriented principles. The format is interactive, often involving a back-and-forth dialogue with the interviewer who might ask follow-up questions to probe deeper into your knowledge. Excelling in software engineering viva questions requires not just knowing the answers but also being able to elaborate, provide context, and discuss trade-offs. They are designed to gauge your foundational knowledge and how you apply abstract concepts to real-world problems, serving as a crucial part of the overall technical evaluation process in many companies. Preparing for these software engineering viva questions is key to demonstrating a robust understanding of the field.
Why Do Interviewers Ask software engineering viva questions?
Interviewers ask software engineering viva questions for several key reasons. Firstly, they want to assess your fundamental understanding of core computer science principles and software engineering concepts. Knowing definitions is one thing, but explaining why something works or when to use a particular approach reveals deeper comprehension. Secondly, these questions evaluate your ability to communicate technical information clearly and concisely. In a team environment, articulating complex ideas to colleagues is vital. Thirdly, viva questions often explore your problem-solving thought process and how you handle ambiguity or challenging theoretical scenarios. They can also reveal your breadth of knowledge across different areas of software engineering, ensuring you have a well-rounded technical background. Finally, follow-up questions allow interviewers to gauge the depth of your expertise and see how you handle pressure or unexpected queries. Preparing for software engineering viva questions helps candidates demonstrate not just memorization but true technical fluency.
What is a baseline in software development?
What is software re-engineering?
What are verification and validation?
What are CASE tools?
What is SRS?
Data structure for tracking 50 integers?
How does a hash table work?
Describe a concurrent hash map.
Difference between a thread and a process?
Explain cache coherency.
What is virtual memory?
What programming languages are you familiar with?
Describe the last project you worked on.
Declarative vs. imperative programming paradigms?
What design patterns do you use?
What is Agile software development?
What are your thoughts on software testing?
Describe a difficult bug you fixed.
Explain technical challenges to non-technical stakeholders?
What aspect of the company interests you most?
How do you determine a project's success?
Implement a HashMap from scratch.
Find the least common ancestor in a tree.
Detect a loop in a linked list.
Determine if a graph is bipartite.
Memory-efficient way to store a vector of integers?
Find pairs summing to a target in an array.
Object inheritance and object composition?
Monolithic vs. microservices architecture?
Handle concurrency in multi-threaded environments?
Preview List
1. What is a baseline in software development?
Why you might get asked this:
Assess understanding of configuration management and project stability milestones. Shows awareness of controlled development processes.
How to answer:
Define baseline and its purpose. Explain it as a reference point for change control and project management.
Example answer:
A baseline is a formally reviewed and agreed-upon specification for a software product component at a specific point in its life cycle. It serves as the basis for further development and can only be changed through formal change control procedures.
2. What is software re-engineering?
Why you might get asked this:
Tests knowledge of software maintenance, evolution, and modernization techniques beyond initial development.
How to answer:
Define re-engineering as restructuring/updating existing software for improvement, not just bug fixing or adding features.
Example answer:
Software re-engineering is the process of examining and altering a software system to reconstitute it in a new form, including adding new functionalities or improving performance and maintainability without changing its core purpose.
3. What are verification and validation?
Why you might get asked this:
Crucial concepts in software quality assurance. Tests understanding of ensuring product correctness and meeting user needs.
How to answer:
Distinguish between them clearly: Verification asks "Are we building the product right?" Validation asks "Are we building the right product?".
Example answer:
Verification ensures the software conforms to specifications (checking against the plan). Validation ensures the software meets customer requirements (checking if it solves the problem). Both are essential for quality.
4. What are CASE tools?
Why you might get asked this:
Evaluates familiarity with tools that support and automate software development processes.
How to answer:
Explain that CASE stands for Computer-Aided Software Engineering tools and provide examples of tasks they assist with in the SDLC.
Example answer:
CASE tools are software applications used to support and automate activities throughout the software development lifecycle, such as requirements analysis, design modeling, code generation, testing, and project management.
5. What is SRS?
Why you might get asked this:
Assesses understanding of foundational project documentation and communication between stakeholders and developers.
How to answer:
State what SRS stands for and describe its purpose as a comprehensive document outlining software requirements.
Example answer:
SRS stands for Software Requirements Specification. It's a document that completely describes the behavior and functionality of a software system, serving as an agreement between customers and developers regarding what the software will do.
6. Data structure for tracking 50 integers and checking presence/removing oldest if full?
Why you might get asked this:
Tests practical application of data structures under specific constraints (fixed size, FIFO-like removal).
How to answer:
Propose a suitable data structure (like a circular buffer or queue) and explain why it fits the requirements.
Example answer:
A circular buffer or a queue implemented with a fixed-size array would work well. When full, enqueueing a new element automatically overwrites/removes the oldest element at the head, while maintaining O(1) lookup if using an auxiliary hash set.
7. How does a hash table work?
Why you might get asked this:
Fundamental data structure question. Assesses understanding of key-value storage and underlying mechanisms.
How to answer:
Explain the core concept: using a hash function to map keys to indices in an array, and briefly mention collision handling.
Example answer:
A hash table stores key-value pairs. It uses a hash function to compute an index (or bucket) in an array where the value is stored. When different keys hash to the same index (collision), techniques like chaining or open addressing are used.
8. Describe a concurrent hash map and its operation.
Why you might get asked this:
Tests knowledge of concurrent data structures and thread safety, critical in multi-threaded programming.
How to answer:
Explain its purpose (thread-safe map) and how it allows concurrent reads/writes, often mentioning segment locking or similar techniques.
Example answer:
A concurrent hash map is a thread-safe hash map implementation. Unlike a synchronized map that locks the whole structure, concurrent maps typically use finer-grained locking (like segment locks) allowing multiple threads to access different parts simultaneously for better performance.
9. Difference between a thread and a process?
Why you might get asked this:
Basic operating systems concept. Essential for understanding concurrency and resource management.
How to answer:
Clearly define both. Highlight that processes have independent memory spaces while threads within a process share memory and resources.
Example answer:
A process is an instance of a program running with its own memory space and resources. A thread is a smaller unit of execution within a process, sharing the process's memory and resources. Processes require more overhead to create and switch.
10. Explain cache coherency in single-core and multi-core systems.
Why you might get asked this:
Relevant for performance optimization and understanding hardware-software interaction, especially in modern multi-core CPUs.
How to answer:
Define cache coherency (data consistency across caches). Explain the difference: simpler in single-core (only one cache), complex in multi-core requiring protocols (like MESI).
Example answer:
Cache coherency ensures that multiple copies of the same data residing in different caches are kept consistent. In single-core, it's simple. In multi-core, it's complex; protocols like MESI (Modified, Exclusive, Shared, Invalid) manage cache lines across cores to maintain consistency.
11. What is virtual memory?
Why you might get asked this:
Core operating system concept. Assesses understanding of memory management and how programs use more memory than physically available.
How to answer:
Define virtual memory as a memory management technique. Explain how it uses disk space to extend RAM and provides memory isolation.
Example answer:
Virtual memory is an OS technique that allows programs to use more memory than physically installed RAM. It maps virtual addresses used by programs to physical addresses in RAM or disk, creating the illusion of a large, contiguous memory space and providing memory protection.
12. What programming languages are you familiar with?
Why you might get asked this:
Standard introductory question. Gauges your technical stack and breadth of experience.
How to answer:
List languages you are proficient in. Briefly mention experience level or context if relevant.
Example answer:
I am proficient in Java, Python, and JavaScript. I have professional experience using Java for backend development and Python for scripting and data analysis, and I'm comfortable with JavaScript for frontend work.
13. Describe the last project you worked on.
Why you might get asked this:
Provides insight into your practical experience, role, technical contributions, and problem-solving skills.
How to answer:
Briefly explain the project's goal, your role, the technologies used, and a key contribution or challenge you faced.
Example answer:
My last project involved developing a microservice for processing user data using Spring Boot and Kafka. I was responsible for designing the data processing pipeline and implementing the REST API endpoints, focusing on ensuring high throughput and data integrity.
14. What are your thoughts on declarative vs. imperative programming paradigms?
Why you might get asked this:
Tests understanding of different programming styles and their trade-offs. Shows ability to think abstractly about code.
How to answer:
Define each paradigm. Explain the difference (what vs. how). Mention contexts where each might be preferred.
Example answer:
Imperative programming focuses on how to achieve a result by specifying control flow (like C++). Declarative programming focuses on what the result should be, without detailing the steps (like SQL or React). Declarative code is often more concise and easier to reason about.
15. What design patterns do you use and in what context?
Why you might get asked this:
Assesses familiarity with established solutions to common design problems. Shows ability to write maintainable and scalable code.
How to answer:
Name a few patterns you've used and explain a specific scenario where applying the pattern was beneficial.
Example answer:
I frequently use the Factory pattern for object creation when the exact type isn't known until runtime. The Observer pattern is useful for implementing distributed event handling, allowing objects to subscribe to changes in others without tight coupling.
16. What is Agile software development?
Why you might get asked this:
Tests knowledge of modern software development methodologies and collaborative practices.
How to answer:
Define Agile as an iterative, flexible approach. Mention core principles like collaboration, responding to change, and delivering working software.
Example answer:
Agile is an iterative methodology emphasizing flexible planning, evolutionary development, early delivery, and continuous improvement. It values individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration, and responding to change.
17. What are your thoughts on software testing?
Why you might get asked this:
Highlights your commitment to quality and understanding of different testing phases and strategies.
How to answer:
State that testing is crucial for quality. Mention different types of testing you value (unit, integration, etc.) and why.
Example answer:
Software testing is fundamental to building reliable systems. I believe in a shift-left approach, focusing on thorough unit and integration testing early in development. Test automation is also key for maintaining velocity and catching regressions quickly.
18. Describe a difficult bug you fixed.
Why you might get asked this:
Assesses your debugging process, problem-solving skills under pressure, and ability to learn from challenges.
How to answer:
Describe the bug, the symptoms, your process for diagnosing it, the fix, and maybe a lesson learned.
Example answer:
I once tracked down a memory leak in a long-running background process. It wasn't immediately obvious as it manifested only after days. I used heap profiling tools to identify an object graph that wasn't being garbage collected correctly and refactored the object lifecycle management to fix it.
19. How do you explain technical challenges to non-technical stakeholders?
Why you might get asked this:
Evaluates your communication skills and ability to bridge the gap between technical details and business impact.
How to answer:
Focus on simplifying technical jargon. Use analogies and relate issues directly to business outcomes (cost, time, user impact).
Example answer:
I focus on the 'what' and 'why' rather than the 'how'. I explain the impact on project goals, timeline, or budget using clear, simple language and analogies, avoiding technical terms where possible, to ensure they understand the implications.
20. What aspect of the company interests you most?
Why you might get asked this:
Gauges your genuine interest in the company and role. Shows you've done your research.
How to answer:
Reference something specific about the company's mission, technology, culture, or recent projects that genuinely excites you.
Example answer:
I'm particularly interested in your work on [specific technology/product/mission]. The challenges involved in [specific problem area] align perfectly with my skills and passion for [related field], and I admire your company's innovative approach.
21. How do you determine a project's success?
Why you might get asked this:
Tests understanding of project management concepts and aligning technical work with business objectives.
How to answer:
Go beyond just 'completing it'. Include factors like meeting requirements, budget/timeline, user satisfaction, and business value delivered.
Example answer:
Success goes beyond on-time/on-budget delivery. It's about whether the project met its original goals, delivered tangible value to users or the business, was maintainable, and if the team felt successful and learned valuable lessons.
22. Implement a HashMap from scratch.
Why you might get asked this:
Deep test of data structure implementation knowledge, including hashing and collision resolution.
How to answer:
Outline the core components: an array (buckets), a hash function, and a collision handling strategy (chaining or open addressing).
Example answer:
You'd need an array to serve as buckets. A hash function maps keys to array indices. For collisions, you could use chaining (linked lists at each index) or open addressing (probing for the next available slot). Get/put operations involve hashing the key to find the bucket.
23. Find the least common ancestor of two nodes in a tree.
Why you might get asked this:
Classic tree algorithm question. Assesses understanding of tree traversal and relationships.
How to answer:
Explain the concept of LCA. Describe an approach, such as tracking paths from root or using a recursive method for binary trees.
Example answer:
For a binary search tree, you can traverse from the root; if both nodes are on the same side of the current node, move to that child; otherwise, the current node is the LCA. For a general tree, find paths from the root to both nodes and find the last common node in the paths.
24. Detect a loop in a linked list.
Why you might get asked this:
Classic linked list problem. Tests algorithm knowledge and ability to use pointers effectively.
How to answer:
Describe Floyd's cycle-finding algorithm (tortoise and hare) as the most common and efficient method.
Example answer:
The most common method is Floyd's cycle-finding algorithm. Use two pointers, one slow (moves one step at a time) and one fast (moves two steps). If there's a loop, the fast pointer will eventually catch up to the slow pointer. If the fast pointer reaches null, there's no loop.
25. Determine if a graph is bipartite.
Why you might get asked this:
Tests graph theory knowledge and ability to apply graph traversal algorithms (like BFS or DFS) for specific properties.
How to answer:
Explain the definition of a bipartite graph. Describe how to use graph traversal (like BFS) and coloring to check the property.
Example answer:
A graph is bipartite if its vertices can be divided into two disjoint sets such that every edge connects a vertex in one set to one in the other. You can check this using BFS or DFS by trying to color the graph with two colors; if you encounter an edge connecting two vertices of the same color, it's not bipartite.
26. What is a memory-efficient way to store a vector of integers?
Why you might get asked this:
Tests understanding of memory layout and overhead for common data structures.
How to answer:
Mention contiguous memory allocation as key for efficiency. Suggest std::vector (C++) or an array in other languages.
Example answer:
Storing integers in a contiguous block of memory, like a std::vector in C++ or a simple array, is typically memory-efficient because it minimizes overhead associated with separate memory allocations or pointers needed for linked structures.
27. Write a program to find pairs of elements summing to a target in an array.
Why you might get asked this:
Common algorithm problem. Tests ability to optimize solutions for time complexity.
How to answer:
Suggest using a hash set (or map) for O(n) time complexity by storing seen numbers and checking for the complement (target - current).
Example answer:
You can iterate through the array and for each element, check if target - current_element exists in a hash set (or dictionary) containing elements seen so far. If it exists, you've found a pair. Otherwise, add the current element to the set. This is O(n).
28. What are object inheritance and object composition?
Why you might get asked this:
Fundamental object-oriented programming concepts. Tests understanding of code reuse and relationships between objects.
How to answer:
Define both concepts. Explain the "is-a" relationship for inheritance and the "has-a" relationship for composition. Discuss pros/cons briefly.
Example answer:
Inheritance is an "is-a" relationship where a new class (subclass) derives properties and behavior from an existing class (superclass). Composition is a "has-a" relationship where a class contains instances of other classes. Composition is often preferred for flexibility and avoiding issues with inheritance hierarchies.
29. Explain the difference between monolithic and microservices architecture.
Why you might get asked this:
Important system design concept. Tests understanding of architectural styles and their implications.
How to answer:
Define both. Contrast them based on structure, deployment, scalability, and complexity.
Example answer:
A monolithic architecture is a single, tightly coupled application. Microservices architecture is a collection of small, independent services communicating over a network. Monoliths are simpler to deploy initially but harder to scale specific parts; microservices offer better scalability and flexibility but add complexity in management and communication.
30. How do you handle concurrency in a multi-threaded environment?
Why you might get asked this:
Assesses understanding of potential issues (race conditions, deadlocks) and solutions in concurrent programming.
How to answer:
Discuss the challenges (race conditions, deadlocks) and common techniques used to manage access to shared resources (locks, semaphores, mutexes, concurrent data structures).
Example answer:
Handling concurrency requires managing access to shared resources to prevent issues like race conditions and deadlocks. I use synchronization primitives like mutexes or locks to protect critical sections. Utilizing concurrent-friendly data structures and designing thread-safe code patterns are also key strategies.
Other Tips to Prepare for a software engineering viva questions
Beyond mastering the technical content, effective preparation for software engineering viva questions involves several key strategies. Practice articulating your thoughts clearly and concisely. Verbalize your answers, perhaps even recording yourself, to identify areas where your explanations are unclear or rambling. "Confidence comes from preparation," as they say, and being able to explain complex ideas aloud builds that confidence. Don't just memorize answers; understand the why behind each concept. Interviewers often ask follow-up questions to probe deeper, and a solid understanding is crucial for handling these. Mock interviews, especially those simulating a viva format, are invaluable. They help you get comfortable with the pressure and structure of the interview. Utilize resources like online coding platforms, textbooks, and reputable tech blogs to reinforce your foundational knowledge. Consider using AI-powered tools designed for interview practice, such as the Verve AI Interview Copilot, which can provide realistic simulations and feedback on your responses to various software engineering viva questions. Verve AI Interview Copilot, available at https://vervecopilot.com, offers tailored practice sessions, helping you refine your explanations and build confidence. Preparing thoroughly and practicing articulation will significantly improve your performance in software engineering viva questions. As another quote suggests, "The only way to do great work is to love what you do," but the only way to get to do great work is often to ace the interview.
Frequently Asked Questions
Q1: How technical are software engineering viva questions?
A1: They are highly technical, focusing on core computer science fundamentals, algorithms, data structures, and software engineering principles.
Q2: Should I memorize answers for software engineering viva questions?
A2: No, focus on understanding concepts and being able to explain them clearly; memorization alone won't help with follow-ups.
Q3: How long is a typical software engineering viva session?
A3: It can vary, but often ranges from 30 minutes to an hour, depending on the company and the role.
Q4: Are there behavioral software engineering viva questions?
A4: Sometimes, interviewers mix in questions about teamwork, problem-solving approach, or handling difficult situations alongside technical ones.
Q5: How should I handle a question I don't know the answer to?
A5: Be honest, state you don't know, but offer to discuss related concepts or how you would approach finding the answer.
Q6: Is it okay to ask clarifying questions during a viva?
A6: Absolutely, it shows engagement and ensures you understand the question correctly before attempting to answer.
