40 questions with answers for candidates with 1 year of experience — 19 easy, 20 medium, 1 hard.
What interviewers expect: 1 year experience
Interviewers check that you can work independently on a module: understanding user stories, designing technique-based tests, running regression, logging and retesting defects, and taking part in Agile ceremonies. Questions mix CTFL concepts with real project examples, so be ready to explain one defect you found and how you reported it.
This set is weighted towards White-Box, Experience and Collaboration-Based Testing (8), Test Tools and Exam Preparation (7), Black-Box Test Techniques (6), Testing Throughout the SDLC (5).
Agile testing activities Regression and confirmation testing Severity and priority Requirement reviews
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01
Ten automated tests fail overnight, but the cause is an expired SSL certificate in the test environment. How should this be reported?
These failures are caused by the environment, not the test object, so they should not be logged as product defects. I would raise one environment issue with the infrastructure team, mark the test results as blocked or environment failure, and re-run after the certificate is renewed. I would also suggest monitoring certificate expiry so the same false positives do not recur.
02
Payment type has 3 partitions (card, UPI, wallet) and customer type has 2 (new, existing). What is the minimum number of tests for Each Choice coverage?
Each Choice coverage needs every partition from each input used at least once, and one test can cover one partition of each input at the same time. So the minimum equals the largest number of partitions: 3. Example tests: card with new, UPI with existing, wallet with new. Covering all combinations would need 3 x 2 = 6 tests, which is not required for Each Choice.
User acceptance testing is done by intended users. Operational acceptance testing is done by operations staff and covers backup, restore, installation and disaster recovery. Contractual and regulatory acceptance testing checks contract criteria or legal rules. Alpha testing is done by potential users at the developer's site, and beta testing by users at their own locations. Acceptance testing mainly builds confidence and validates fitness, not defect finding.
04
What is static testing and how is it different from dynamic testing?
Static testing examines work products without executing them, through manual reviews or static analysis tools. Dynamic testing executes the software. Static testing finds defects directly, such as ambiguous requirements or coding standard violations, while dynamic testing causes failures whose defects are then located by debugging. Static testing works on non-executable products like requirements and test plans, and finds defects dynamic testing cannot, such as unreachable code.
05
Discounts depend on several combined business rules such as membership, coupon and festival offers. Which technique do you choose?
Decision table testing fits best, because the outcome depends on combinations of conditions. I would list the conditions and actions, build the full table, remove infeasible combinations, minimise columns where a condition does not matter, and turn each column into a test case. The table also exposes gaps or contradictions in the rules, which I would raise with the business analyst before testing.
06
What is statement testing and how is statement coverage calculated?
Statement testing designs tests that execute the executable statements in the code. Statement coverage = statements executed by the tests / total executable statements x 100. Reaching 100 percent means every executable statement ran at least once, so a defect in any statement may be triggered. However, it does not guarantee that all decision logic is tested, for example the false outcome of an if without an else.
07
Tell me about an exploratory testing session that found a critical defect.
Situation: a ticket booking app had passed all scripted tests. Task: run a one-hour exploratory session on seat selection. Action: I tried quick double taps, switching networks and booking the same seat from two devices. Result: two users could book the same seat. I logged a detailed report with videos, it was fixed before release, and concurrency tests were added to the regression suite.
08
How do you prioritise your work when several tasks are urgent?
Situation: in my internship I had regression tests, a defect retest and a test case review due the same day. Task: finish what mattered most. Action: I asked my lead which item blocked the release, did the defect retest first since a fix depended on it, then the high-risk regression tests, and moved the review to the next morning with agreement. Result: the release stayed on track.
09
A quantity field accepts 1 to 100. List the 2-value BVA test values.
The valid partition is 1 to 100, with invalid partitions below and above it. For each boundary, take the boundary and its closest neighbour in the adjacent partition. Lower boundary: 0 and 1. Upper boundary: 100 and 101. So 2-value BVA needs four values: 0, 1, 100 and 101, and four test cases give 100 percent 2-value boundary coverage.
White-box testing considers the whole implementation, so it can find defects even when the specification is vague, outdated or incomplete. Coverage gives an objective measure of thoroughness. It can also be used in static testing, for example dry runs of code or pseudocode. Its main weakness is that it cannot detect omissions: if a requirement was never implemented, no white-box test will notice it.
11
A developer says one value per partition is enough. Why might you still add boundary tests?
Equivalence partitioning assumes all values in a partition behave the same, but many defects occur at the edges, where developers write '>' instead of '>=' or use the wrong limit. One middle value like 35 in an 18 to 60 range will never reveal these. Boundary value analysis adds tests at 17, 18, 60 and 61, so the two techniques together give good coverage with few tests.
1) Testing shows the presence, not the absence, of defects. 2) Exhaustive testing is impossible, so use test techniques, prioritisation and risk. 3) Early testing saves time and money. 4) Defects cluster together in a few components. 5) Tests wear out, so update them or write new ones. 6) Testing is context dependent. 7) Absence-of-defects fallacy: a defect-free system can still fail if it does not meet user needs.
13
How many tests are needed for full statement and branch coverage of this nested code?
if a > 0:
if b > 0:
s1
else:
s2
else:
s3
Statement coverage needs 3 tests, because s1, s2 and s3 are on different paths.
Branch coverage also needs 3: (a > 0, b > 0), (a > 0, b <= 0) and (a <= 0).
With full if-else structures, both criteria need the same number of tests.
14
Write a sample defect report for a failed coupon code.
BVA applies to ordered partitions. In 2-value BVA each boundary has two coverage items: the boundary value and its closest neighbour in the adjacent partition. In 3-value BVA there are three: the boundary and both neighbours. For a valid range 18 to 60, 2-value gives 17, 18, 60, 61, and 3-value gives 17, 18, 19, 59, 60, 61. 3-value is stricter and can catch defects like 'x == 18' written instead of 'x >= 18'.
16
A key tester resigns and a vendor will deliver a module late. How do you treat these risks?
Both are project risks. For the resignation, I would mitigate by documenting knowledge, pairing another tester for a handover and adjusting assignments; a contingency plan could be a short-term contractor. For the vendor delay, I would monitor delivery dates, prepare stubs to test our side, reorder testing to start other modules first and agree a contingency with management.
17
A review is led by the author, and its goals are to educate the team and reach consensus. Which review type is it?
It is a walkthrough. Walkthroughs are led by the author, and their objectives include educating reviewers, building consensus, generating new ideas, motivating authors and detecting anomalies. Individual preparation is optional. If a trained moderator led it with technical experts to make technical decisions, it would be a technical review; if it followed a fully formal process with metrics, it would be an inspection.
18
What changed in CTFL v4.0 compared with the 2018 syllabus?
v4.0 added Agile and DevOps content: the whole team approach, test-first approaches like TDD, ATDD and BDD, shift-left, retrospectives, collaboration-based test approaches, the test pyramid and testing quadrants. It renamed the pesticide paradox to 'tests wear out', removed use case testing and decision coverage, focused white-box testing on statement and branch coverage, and described test roles instead of job titles.
19
Match these tasks to test activities: identifying test conditions, creating test data and suites, comparing actual and expected results, archiving testware.
Identifying and prioritising test conditions is test analysis. Creating test data, arranging test procedures and assembling test suites is test implementation. Running tests and comparing actual with expected results is test execution. Archiving testware, handing it over and recording lessons learned is test completion. Exams often mix design and implementation: designing test cases is test design, while preparing them to run is implementation.
20
Suggest a four-week study plan for a fresher preparing for CTFL v4.0.
Week 1: chapters 1 and 2, the seven principles, test activities, test levels and test types; make notes of key terms. Week 2: chapter 3 and black-box techniques, solving at least 30 EP, BVA, decision table and state transition problems. Week 3: white-box and experience-based techniques, chapters 5 and 6, with estimation and risk exercises. Week 4: three or more timed sample exams and revision of mistakes.
Component testing checks individual units in isolation. Component integration testing checks interfaces and interactions between components. System testing checks overall behaviour, both functional and non-functional. System integration testing checks interfaces with other systems and external services. Acceptance testing focuses on validation and readiness for deployment. Each level has its own objectives, test basis, test objects, typical defects and responsibilities.
22
Find the minimum tests for 100 percent statement and branch coverage of this code.
read(x)
if x > 10:
print('big')
print('done')
Statement coverage: one test with x = 15 executes every statement, so 1 test.
Branch coverage: the if has a true and a false outcome, so tests with x = 15 and x = 5 are needed, 2 tests.
23
Why do you want to start your career in software testing?
Model answer: I enjoy finding how things break and thinking from the user's side. During my degree I tested our team project and found issues others missed, which built my interest. I studied the ISTQB Foundation syllabus to learn standard terms and techniques. I want to grow from manual testing into automation and domain expertise, and testing lets me understand the whole product and the full SDLC.
24
Why is traceability between the test basis and testware important?
Traceability links test basis items such as requirements, risks and user stories to test conditions, test cases, results and defects. It lets teams measure coverage, assess the impact of changes, support audits in regulated domains and report progress in business terms, for example 'requirement R12 has three passed tests and one open defect'. When a requirement changes, traceability shows exactly which tests must be updated or re-run.
25
An exam question asks for the 'best' answer and two options seem correct. How do you decide?
Re-read the stem for keywords such as 'most likely', 'best', 'first' or 'not'. Compare both options strictly against the syllabus wording, not your company's practice. Often one option is partly true or too absolute, using words like 'always' or 'guarantees'. Choose the option that fully matches the syllabus definition. Practising official sample exams builds this habit.
26
What is checklist-based testing and what are its risks?
In checklist-based testing, the tester designs and runs tests to cover the conditions on a checklist built from experience, user needs or knowledge of why software fails. Items should be specific and testable, not vague or automatable by tools. Checklists give some consistency and guidance when detailed test cases are missing, but they become less effective over time as developers learn to avoid those mistakes, so they must be updated regularly.
27
The product owner writes vague acceptance criteria such as 'search should work well'. What do you do?
I would suggest a short three-amigos session with the product owner and a developer. Together we would turn the vague criterion into testable ones, for example 'searching by product name returns matching items sorted by relevance', 'no results shows a helpful message' and 'results load in under 2 seconds'. Writing them as Given/When/Then scenarios makes them clear and ready for ATDD.
Register through the ISTQB member board for India or an ISTQB-accredited exam provider. Create an account, choose CTFL v4.0, and pick either an online proctored exam or a test centre. For online exams, check your webcam, microphone and internet in advance, and keep a valid government photo ID ready. Results are usually shared soon after the exam, followed by the certificate.
29
You have three years of testing experience and three weeks to prepare for CTFL. How do you plan?
Experience helps, but the exam follows syllabus wording, not company practice. Week 1: read chapters 1 to 3 and the glossary terms in each learning objective. Week 2: study chapters 4 to 6, practise BVA, decision tables, state transitions, coverage and estimation calculations. Week 3: take timed official sample exams, analyse every wrong answer against the syllabus, and revise weak chapters.
30
Which good testing practices apply regardless of the SDLC model?
CTFL v4.0 lists these: for every software development activity there is a corresponding test activity; each test level has its own specific objectives; test analysis and design for a level begin during the corresponding development phase; and testers are involved in reviewing work products as soon as drafts are available. Together these practices support early testing and quality control in waterfall, V-model and Agile projects alike.
31
A developer says your defect cannot be reproduced. What do you do?
I would re-check that I can reproduce it, then add missing details: exact build version, environment, browser or device, user role, test data, timestamps, logs and a screen recording. I would check whether it is intermittent and note the frequency. If needed, I would reproduce it live with the developer. If it truly cannot be reproduced, we can keep it open with monitoring rather than close it.
An informal review has no defined process or formal output and aims to detect anomalies. A walkthrough is led by the author and aims to educate, build consensus, generate ideas and detect anomalies. A technical review is done by technically qualified reviewers led by a moderator, aiming at consensus and technical decisions. An inspection is the most formal, follows the full process, collects metrics and aims to find the maximum number of anomalies.
33
What is branch testing and how is branch coverage measured?
A branch is a transfer of control between two nodes in the control flow graph. Branches can be unconditional, like straight-line code, or conditional, like the true and false outcomes of an if or the cases of a switch. Branch coverage = branches exercised / total branches x 100. Branch testing designs tests so that every branch, including the hidden false path of an if without else, is exercised.
34
Your automated regression suite fails randomly, and the team no longer trusts it. What do you do?
Flaky tests are a known automation risk. I would quarantine flaky tests so they do not block the pipeline, then find the causes: hard-coded waits, shared test data, test order dependency or unstable environments. Fixes include explicit waits, independent test data, isolated environments and retries only for known infrastructure issues. I would track the flaky rate and return fixed tests to the main suite.
35
What is risk, and how do project risks differ from product risks?
A risk is a potential event or condition whose occurrence causes an adverse effect. Risk level is determined by likelihood and impact. Project risks affect the management and control of the project, such as staff shortages, delays, budget cuts, vendor problems or tool issues. Product risks relate to quality characteristics of the product, such as missing functionality, wrong calculations, slow response, poor security or bad usability.
36
Why is early and frequent stakeholder feedback important?
Early and frequent feedback catches misunderstandings about requirements before they become expensive. Without it, the product may not match what stakeholders want, leading to costly rework, missed deadlines, blame games and even project failure. Regular feedback through reviews, demos and backlog refinement keeps the team focused on the most valuable features and builds a shared understanding of what is being built.
37
How does component integration testing differ from system integration testing?
Component integration testing focuses on interfaces between components of the same system and is usually done by developers or testers who know the architecture, often with stubs and drivers. System integration testing focuses on interfaces with other systems and external services, such as payment gateways or government APIs, and needs production-like environments. Incremental integration, top-down or bottom-up, is preferred over big-bang because it localises defects.
38
Are there prerequisites for CTFL, and does the certificate expire?
There are no formal prerequisites for the Foundation Level exam; students, freshers and experienced professionals can all take it, although some practical testing exposure makes the syllabus easier. The CTFL certificate has lifetime validity and does not need renewal. It is the prerequisite for ISTQB Advanced Level and most Specialist certifications, so it is the starting point of the ISTQB path.
39
An age field accepts 18 to 60. Apply equivalence partitioning. How many tests give 100 percent EP coverage?
There are three partitions: below 18 (invalid), 18 to 60 (valid) and above 60 (invalid). Pick one value from each, for example 10, 35 and 70. So three test cases give 100 percent EP coverage. Test invalid partitions one at a time so that one invalid value does not hide another, and confirm with the specification whether non-numeric input forms another invalid partition.
40
Tell me about a time you missed a defect. What did you learn?
Situation: a defect in date formatting reached production after my testing. Task: understand why and prevent it. Action: I owned the miss, found my test data used only one locale, and added test cases for other date formats and locales. I also shared a checklist for locale testing. Result: no similar defect appeared in later releases, and I learned to review my test data as carefully as my test steps.
Frequently asked questions
What is asked in ISTQB interviews for 1 year of experience?
Interviewers check that you can work independently on a module: understanding user stories, designing technique-based tests, running regression, logging and retesting defects, and taking part in Agile ceremonies. Questions mix CTFL concepts with real project examples, so be ready to explain one defect you found and how you reported it.
How many questions should I practise before a ISTQB interview?
Work through all 40 questions here, then the company-wise sets for the employers you are targeting. Quality matters more than count: be able to explain why each answer is right.
Which topics matter most for 1 year of experience?
Focus first on Agile testing activities, Regression and confirmation testing, Severity and priority, Requirement reviews.