The Software Development Life Cycle (SDLC) is the basic process that guides every project from start to finish. It breaks work into steps like planning, designing, building, testing, and delivering, so projects are completed on time, within budget, and with good quality. To do well in interviews, it’s not enough to just know the names of these steps, as you also need to understand how different models, tools, and methods are used in real projects.
In this blog, we’ve collected the Top 35 SDLC interview questions and answers to help you prepare. Whether you’re a beginner learning the basics, a professional wanting to strengthen your knowledge, or someone aiming for senior roles, you’ll find useful questions here. The topics cover models like Waterfall, Spiral, Agile, and RAD, along with concepts such as risk management, scope creep, Scrum, testing types, and CMM. Going through these will help you feel confident and ready for both simple and tricky interview questions.
At its core, SDLC is about creating reliable, high-quality software most effectively. By following its steps, teams can make sure products are tested, efficient, and ready for use, whether in software or hardware projects.
For your convenience, we’ve divided the Top 35 SDLC interview questions into three parts: for freshers, intermediates, and experienced professionals. We have also listed some important questions on Software Development Life Cycle (SDLC) in this blog. So, let’s get started!
SDLC Interview Questions for Freshers
1. What is SDLC?
The Software Development Life Cycle (SDLC) is a structured approach to developing software that ensures high-quality output, cost efficiency, and timely delivery. It defines a step-by-step process to plan, design, develop, test, and deploy software effectively.
Each stage in the SDLC has clear goals, deliverables, and tasks, ensuring that the final software product meets user expectations and industry standards.
2. Explain LLD.
LLD, or Low-Level Design, is the process of creating a detailed design of each module in a software system after the High-Level Design (HLD) phase. It describes the actual logic for each system component, the specifications of every module, and how they interact.
Every program undergoes logic design, which is documented as program specifications, and a unit test plan is prepared for each module. LLD is sometimes referred to as detailed or module-level design, and it serves as a clear guide for developers to implement features accurately and efficiently.
3. Explain HLD.
HLD, or High-Level Design, defines the overall architecture and structure of a software system. It provides a complete overview of the application, including system architecture, database design, services, platforms, and relationships between modules.
HLD outlines the primary modules and all submodules, giving a clear picture of the system’s flow. Architects create the High-Level Design to guide developers and ensure the development process begins with a well-structured blueprint, helping them understand how the entire system works.
4. What are the advantages of the SDLC process?
The advantages of the SDLC process lie in its structured approach to software development, which ensures high-quality results and alignment with business goals. At the end of each phase, formal reviews allow management to monitor progress and maintain control over the project.
SDLC also creates detailed documentation, which links system requirements to business objectives and serves as a reference throughout development. Producing intermediate deliverables at each stage allows teams to verify that the software meets user needs and industry standards, and make improvements if necessary.
This approach reduces errors, improves efficiency, and ensures the final product delivers exactly what the company and its users expect.
5. What are the disadvantages of the SDLC process?
Before you begin, make sure you understand all of the details of the project. During the development phase, there is often a lot of paperwork involved. Moreover, it becomes difficult to make changes during development due to limited flexibility.
If the planning isn’t done properly, the project will take longer and cost more. Also, when there are a lot of flaws in the code, fixing them can take a long time and cause deadlines to be missed. This can directly impact project delivery. While SDLC provides structure and quality control, it may be less adaptable for projects with frequently changing requirements.
6. Explain why do we need SDLC.
Software development involves many tasks that must be completed in a sequential order. Each phase depends on the output of the previous one, and multiple teams work together on the project. SDLC ensures that this process is organized, so every team knows what to do and when. By following SDLC, tasks are coordinated smoothly, goals are clear, and handoffs between teams happen without confusion.
For example, development cannot start until requirements are gathered, and testing cannot begin until development is complete. SDLC ensures that each team can work efficiently, with all necessary inputs and outputs defined, making it an essential part of any software project.
7. What are the different Phases of SDLC?
This is one of the most commonly asked questions in SDLC interviews. The Software Development Life Cycle (SDLC) generally consists of six main phases: Requirement Gathering and Analysis, Design, Implementation (Coding), Testing, Deployment, and Maintenance. Let’s understand them in detail:
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- Requirement Gathering and Analysis: In this phase, all the necessary information is collected from the customer, either in person or virtually, to understand their needs. This information is critical for designing a product that meets customer expectations. Any ambiguities should be clarified during this stage to avoid issues later in the development process.
- Design: Once requirements are gathered, they are documented in an SRS (Software Requirement Specification) document. Based on this, the overall architecture and design of the software are created while keeping customer needs in mind.
- Implementation (Coding): During this phase, developers translate the design into functional source code. The application becomes executable and is developed according to the specifications outlined in the SRS document.
- Testing: After development, the software is released to the testing team. Testers verify whether the application meets customer requirements and report any bugs or issues. Developers then fix these issues to ensure the software works as intended.
- Deployment: Once testing is complete, the product is deployed to the production environment or undergoes User Acceptance Testing (UAT), depending on customer requirements. In UAT, a replica of the production environment is created, and the customer tests the software along with the developers. Once the customer approves, the software goes live.
- Maintenance: After deployment, developers handle the maintenance of the software. This includes fixing any issues that arise and implementing any enhancements or updates needed to keep the product functional and aligned with customer expectations.
8. What is the testing phase in the SDLC model?
The testing phase is one of the most critical steps in the Software Development Life Cycle (SDLC). Its main goal is to evaluate the software thoroughly and ensure that the product meets customer expectations. During this phase, the software is tested to identify bugs, errors, or any deviations from the requirements documented in the SRS (Software Requirement Specification). The testing process involves reporting, monitoring, troubleshooting, and retesting software components until they meet the desired quality standards. Common types of testing during this phase include Quality Assurance (QA) testing, System Integration Testing (SIT), and User Acceptance Testing (UAT), all of which help guarantee a reliable and high-quality product. All levels are as shown below:
9. What is a Feasibility Study?
A feasibility study is a process in the SDLC that checks if a software project is practical and useful for the business. It looks at the project from legal, technical, and business perspectives to make sure it can be developed and implemented successfully. This study helps teams identify risks, estimate costs, and make informed decisions before starting the development.
10. What is SRS?
A Software Requirements Specification (SRS) is a document that describes what a software application will do and how it will work. It helps customers and stakeholders understand if the software meets their needs. The SRS outlines all the required features and functionality of the product. It is prepared after gathering and analyzing all requirements and serves as a foundation for the software development process.
SDLC Interview Questions for Intermediate
1. What is the difference between SDLC and STLC?
If you’re preparing for Software Development Life Cycle Interviews, it’s important to know how SDLC and STLC differ:
SDLC, or Software Development Life Cycle, covers everything from understanding requirements to coding, testing, deployment, and maintenance.
STLC, or Software Testing Life Cycle, is just a part of this process that focuses on testing, including planning tests, running them, and reporting any defects.
2. What is the difference between Verification and Validation?
In interviews, you may be asked how Verification and Validation are different from each other, and here’s how they differ:
Verification ensures that the product is built correctly, focusing on reviewing design documents, specifications, and code to catch issues early.
Validation ensures that the final product meets the user’s needs by testing the actual software against requirements.
3. What are Functional vs Non-Functional Requirements?
Before you start building software, it’s important to know what it should do and how it should behave.
Functional requirements define ‘what’ actions the system must perform, like login, generating reports, or processing payments.
Non-functional requirements define how the system should work to ensure the quality and performance of the system, such as speed, security, and ease of use.
4. Differentiate between quality assurance and quality control?
Quality Assurance (QA):
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- QA is process-focused.
- It ensures that the correct methods, standards, and processes are followed during software development to prevent defects.
- Example: Code reviews, process audits, adherence to coding standards.
Quality Control (QC):
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- QC is product-focused.
- It checks whether the final software meets requirements and is free from defects.
- Example: Functional testing, regression testing, bug fixing.
5. What are the different environments related to development while following SDLC?
When working with SDLC, software goes through different environments to ensure everything works smoothly before reaching real users. These environments help developers, testers, and users test and verify the application safely. Let’s discuss them one by one in brief:
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- Development (Dev): This is where developers write and modify code. It’s a safe workspace where changes can be made without affecting the live system.
- System Integration Testing / Quality Assurance (SIT/QA): In this environment, the software is tested against data, hardware, and software that closely resemble the production system. Testers check if everything works correctly, and any issues are reported for fixing.
- User Acceptance Testing (UAT): Also called the staging environment, this is where end users test the application before it goes live. It ensures the software meets business requirements and behaves as expected.
- Production (PROD): This is the live environment where the software is used by real customers. All previous testing ensures the product is stable and reliable here.
6. List Top SDLC tools.
Here are some of the top SDLC tools used in software development:
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- Jira: A tool used to track tasks, bugs, and manage project workflows. It helps teams plan, monitor progress, and ensure that work is completed on time.
- Git: An open-source version control system that tracks code changes. It allows developers to collaborate, review code, and manage different versions of a project efficiently.
- Confluence: A tool for creating, storing, and sharing project documents, design plans, and research notes. It keeps all team members on the same page.
- Asana: Helps teams organize work and track tasks across different projects. It allows setting deadlines, assigning tasks, and monitoring progress to ensure smooth project execution.
7. What do a Software Project Manager’s responsibilities entail?
A Software Project Manager manages the software project from start to finish. They make sure the entire team follows a clear process, plan the project, track the progress of the project, manage resources, and risks.
8. What are Capability Maturity Model(CMM) levels?
The following are the five Capability Maturity Model Levels:
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- Initial: Processes are unpredictable and chaotic; success depends on individual effort.
- Repeatable: Basic project management practices are in place; work can be repeated and tracked.
- Defined: Processes are documented and standardized for consistent performance.
- Managed: Data on processes and products is collected and monitored.
- Optimized: Processes are continuously improved for better efficiency and quality.
SDLC Interview Questions for Experienced
1. Which of the following is not a life cycle model?
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- Spiral model
- Capability maturity model
- Waterfall model
- Prototyping model
Solution: The correct Answer is (B).
2. What is the appropriate pairing of items in the two columns listing various activities encountered in a software life cycle?
| P. Requirements Capture
Q. Design
R. Implementation
S. Maintenance |
2. Domain Analysis
3. Structural and Behavioral Modeling
1. Module Development and Integration
4. Performance Tuning |
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- P-3, Q-2, R-4, S-1
- P-2, Q-3, R-4, S-1
- P-3, Q-2, R-1, S-4
- P-2, Q-3, R-1, S-4
Solution: The correct Answer is (D).
3. What is the importance of SDLC?
When building software, things can get messy if there’s no plan. SDLC helps teams work step by step, making sure everyone knows what to do at each stage. It keeps the process organized, reduces mistakes, and helps deliver software that actually meets user expectations.
4. Which SDLC model is best and why?
Agile is one of the most popular SDLC approaches, widely adopted due to its flexibility. Unlike other models, Agile allows changes during each sprint, making it suitable for projects where customer requirements change or need frequent feedback. This approach helps teams deliver better software faster while keeping the process flexible.
5. What are the SDLC Models?
There are several models used in SDLC. Some of them are:-
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- Prototype Model
- Waterfall model
- V model
- Incremental model
- Agile model
- Iterative model
- Spiral model
- Rapid Application Development(RAD) model
- Big-bang Model
6. What is the difference between Waterfall and Agile methodologies?
The Waterfall model follows a linear sequence where each phase is completed before moving to the next. It works well for projects with clear and fixed requirements.
However, Agile is iterative and flexible, with teams working in short cycles called sprints. In this, requirements can be reviewed and adjusted as and when required, making it suitable for projects where requirements may change over time.
7. What role does Continuous Integration (CI) play in SDLC?
Continuous Integration, or CI, helps teams catch problems early and keep the code stable. Developers merge their code into a shared repository often, and automated tests are run on it to find issues well in advance. This way, integration problems are minimized, and the software can be delivered faster.
8. How do you handle performance requirements in SDLC?
Performance is part of the software design and testing process.
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- Load testing checks how the system handles normal user activity,
- Stress testing looks at extreme conditions, and
- Scalability analysis ensures the system can handle growth.
- After deployment, monitoring tools track response times and overall performance.
CTA:Want to ace your tech interviews? Start with these SDLC interview questions, and don’t forget to check out our detailed guide on STLC interview questions for complete preparation!
9. How does SDLC support compliance in regulated industries?
In industries like healthcare or aviation, following rules and regulations is crucial.
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- SDLC helps by including compliance checks right from the requirements stage.
- It also keeps clear documentation for audits and makes sure testing covers standards like HIPAA, GDPR, or PCI-DSS.
- Even after deployment, the system is monitored to make sure it stays compliant over time.
Additional Interview Preparation Resources
Important Questions on Software Development Life Cycle (SDLC)
Sometimes we may miss out on some Important SDLC Life Cycle Interview Questions that are most likely asked in the interview. Hence, here’s the list of questions that you may need!
1. Explain prototyping in SDLC process.
Prototyping is creating a simple version of a software application to show how it will work. It may not have the full logic or features of the final product, but it helps developers and customers see the concept in action. The prototype is built, tested, and updated until it meets expectations. This approach is useful when requirements are not fully clear, as it gives an early understanding of what the customer wants and serves as a base for the final system.
2. Briefly describe the RAD model.
The Rapid Application Development (RAD) model is all about building software fast using prototypes instead of detailed designs upfront. It works well when the project can be broken into smaller modules and completed in a couple of months. RAD is useful when you have enough designers for prototyping and the budget covers both their work and tools for automated code generation.
3. How do you apply SDLC in microservices-based architecture?
In microservices, the system is divided into independent services, so the SDLC process adapts accordingly:
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- Each microservice follows its own SDLC pipeline.
- APIs and service contracts are clearly defined for proper interaction.
- Continuous deployment pipelines manage frequent updates efficiently.
- Services are tested individually first, followed by integration testing across all services.
4. How is security embedded in the SDLC process?
Security is most effective when it is integrated into every stage of the Software Development Life Cycle. This practice is known as the Security Development Life Cycle (SecSDLC).
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- During the design stage, teams carry out threat modeling to spot potential risks early.
- In development, secure coding standards, code reviews, and static analysis tools are used to catch vulnerabilities.
- Before deployment, applications go through penetration tests and vulnerability assessments to strengthen defenses.
- After release, continuous monitoring, timely patches, and updates help maintain system security.
5. How do Agile and SDLC align in large-scale enterprise projects?
Agile works with the SDLC by following iterative cycles, but applying it across multiple teams in large enterprises can be complex. To address this, frameworks such as SAFe (Scaled Agile Framework) and LeSS (Large-Scale Scrum) are commonly used.
Requirements are divided into epics, features, and user stories for better management. Integration points are coordinated across teams to prevent conflicts, while regular reviews ensure that development stays aligned with overall business objectives.
6. What are the common challenges in SDLC?
Software projects often face hurdles during the Software Development Life Cycle. Some of the most common challenges include:
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- Changing requirements (scope creep) which disrupt project flow.
- Poor communication between teams leading to misalignment.
- Insufficient testing that results in defects after release.
- Budget or schedule overruns caused by unrealistic planning.
- Lack of documentation making future maintenance difficult.
7. How do you choose the right SDLC model for a project?
Selecting an SDLC model depends on several factors that shape the success of a project:
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- Project size and complexity: Smaller projects may fit Waterfall, while large or complex ones are better suited for Agile or Spiral.
- Customer involvement: Agile works best when clients are highly engaged throughout the process.
- Flexibility of requirements: Rapid Application Development (RAD) is effective when requirements are evolving.
- Time-to-market: Agile or Incremental models are preferred when faster delivery is a priority.
8. How does DevOps fit into SDLC?
DevOps enhances the traditional Software Development Life Cycle by introducing automation, continuous integration (CI), and continuous delivery (CD). It bridges the gap between development and operations teams, enabling faster deployments, improved collaboration, and more reliable software releases.
9. How do you measure success in SDLC?
Success in the Software Development Life Cycle is evaluated using clear metrics such as:
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- On-time delivery to meet planned schedules.
- Staying within budget without overspending resources.
- Meeting requirements to ensure customer satisfaction.
- Low defect density indicates higher software quality.
- High system performance and stability for a reliable user experience.