Skip to content

ISTQB Interview Questions in Kolkata

36 practice questions with answers for ISTQB interviews in Kolkata.

ISTQB jobs in Kolkata

Kolkata has a steady IT-services and BFSI technology job market around Salt Lake Sector V and New Town. Many openings are with service companies and their delivery centres, with a focus on strong fundamentals.

Below are 36 questions that match the mix of service, product and domain employers hiring manual test engineers in Kolkata.

Solved for KolkataStart practicing
3 QUESTIONS FREESign up to unlock the full question bank and track your progress.Unlock every question and answer, then continue practising company-wise and package-wise.
3 questions free Unlock the rest in seconds
01

Why is traceability between the test basis and testware important?

Save to ▾
Show answer
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.
02

What is the value of white-box testing?

Save to ▾
Show answer
White-box testing considers the whole implementation, so it can find defects even when the specification is vague, outdated or incomplete.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.
03

What do the K-levels K1, K2 and K3 mean in the CTFL syllabus?

Save to ▾
Show answer
K-levels describe the cognitive level of each learning objective. K1 is remember: recall a term or fact, such as listing test levels. K2 is understand: explain, compare, classify or give examples, such as distinguishing project and product risks. K3 is apply: use a procedure in a given situation, such as deriving boundary values or calculating a three-point estimate. Most exam questions are K2.
04

Walk through the steps of running a technical review of a design document.

Save to ▾
Show answer
Plan: define scope, objective and exit criteria and choose reviewers with the right expertise. Initiate: share the document, checklist and timeline. Individual review: each reviewer logs anomalies in a shared tool. Communication and analysis: the moderator runs the meeting, the team discusses anomalies and agrees actions. Fixing and reporting: the author updates the document, defects are tracked, and results are checked against exit criteria.
05

How do retrospectives help testing?

Save to ▾
Show answer
A retrospective is held at the end of an iteration, release or project to discuss what went well, what did not and how to improve. For testing, the benefits include more effective and efficient testing, better testware, team bonding, better quality of the test basis and stronger cooperation between developers and testers. Results should be recorded and the improvement actions tracked so that they are actually carried out.
06

Tell me about a time a review you did prevented a serious problem.

Save to ▾
Show answer
Situation: reviewing a refund user story, I noticed it did not say how partial refunds work on discounted orders. Task: clarify it before development started. Action: I logged the gap, set up a 15-minute call with the product owner and developer, and we added three acceptance criteria with worked examples. Result: the feature shipped without the refund calculation errors that had hurt an earlier release.
07

Why does CTFL v4.0 recommend starting non-functional testing early?

Save to ▾
Show answer
Non-functional tests are often left to the end, but late discovery of performance or security problems can threaten the whole project. v4.0 recommends starting early, even at component level, for example measuring response time of a key service. Some tests need special environments such as a usability lab. Many non-functional tests reuse functional tests but measure a different quality, like checking login speed under 500 concurrent users.
08

Order these tests for execution: A (priority 1, depends on C), B (priority 2), C (priority 3), D (priority 2, depends on B). 1 is highest.

Save to ▾
Show answer
A has the highest priority but depends on C, so C must run first, followed by A. Next come the priority 2 tests: B, then D, because D depends on B. The execution order is C, A, B, D. ISTQB exams often include such questions; always satisfy dependencies first, then follow priority, and run the highest priority test as early as its dependencies allow.
09

Write a sample defect report for a failed coupon code.

Save to ▾
Show answer
ID: DEF-1042. Title: Checkout - valid coupon SAVE10 rejected as expired. Build: 3.4.1, staging, Chrome 130 on Windows. Preconditions: logged-in user, cart value 1,500 rupees. Steps: open checkout, enter SAVE10, click Apply. Expected: 10 percent discount applied. Actual: error 'Coupon expired' although valid until 31 December. Attachments: screenshot, console log. Severity: major. Priority: high. Reference: TC-CHK-018.
10

What is branch testing and how is branch coverage measured?

Save to ▾
Show answer
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.
11

How does testing relate to quality assurance and quality control?

Save to ▾
Show answer
Testing is a form of quality control (QC): a product-oriented, corrective approach that checks work products. Quality assurance (QA) is process-oriented and preventive: it improves processes on the idea that a good process produces a good product. Test results are used by both. QC uses them to fix defects, and QA uses them as feedback on how well the development and test processes are performing.
12

What does the principle 'tests wear out' mean, and what was it called earlier?

Save to ▾
Show answer
In v4.0 the old 'pesticide paradox' was renamed 'tests wear out'. If the same tests are repeated many times, they become less effective at finding new defects because the code they exercise has already been fixed. Testers should modify existing tests and test data and write new tests. The exception is automated regression testing, where repeating the same tests is valuable because the goal is to confirm nothing has broken.
13

How does a tester contribute to release and iteration planning?

Save to ▾
Show answer
In release planning, testers help write testable user stories and acceptance criteria, take part in product and quality risk analyses, estimate test effort for stories, define the test approach and plan release testing. In iteration planning, they join detailed risk analysis of stories, check testability, break stories into testing tasks, estimate testing effort and identify the functional and non-functional aspects to test.
14

A module of 15,000 lines of code has 45 defects. Calculate its defect density and explain how you would use it.

Save to ▾
Show answer
Defect density = defects / size = 45 / 15 KLOC = 3 defects per KLOC. If other modules average 1 defect per KLOC, this module is a defect cluster, so I would increase test depth there, ask for a code review or refactoring, and add more regression tests. Compare density only across similar code, because language and complexity affect the numbers.
15

How did you give feedback on a senior colleague's document that had many issues?

Save to ▾
Show answer
Situation: a senior architect's design missed several error-handling flows. Task: give feedback respectfully. Action: I grouped comments by theme, framed them as questions with concrete examples, noted the strong sections, and offered to discuss in person rather than only posting comments. Result: he accepted most points, appreciated the clear feedback, and later invited me to review his designs earlier.
16

Compare TDD, ATDD and BDD.

Save to ▾
Show answer
All three are test-first approaches. In TDD, developers write a failing unit test, write code to pass it, then refactor. In ATDD, acceptance tests are derived from acceptance criteria with the team and business before development starts. In BDD, desired behaviour is written as Given/When/Then scenarios in natural language that stakeholders understand and that can be turned into executable tests. All three support shift-left.
17

How does component integration testing differ from system integration testing?

Save to ▾
Show answer
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.
18

Why does 100 percent branch coverage guarantee 100 percent statement coverage, but not the other way round?

Save to ▾
Show answer
Every statement lies on at least one branch, so exercising all branches executes all statements. The reverse fails when a decision has an empty outcome. Example: 'if x > 10: print(big)' followed by 'print(done)'. One test with x = 15 runs every statement, giving 100 percent statement coverage, but the false branch is never taken, so branch coverage is only 50 percent. This is called subsumption.
19

Which good testing practices apply regardless of the SDLC model?

Save to ▾
Show answer
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.
20

Show the TDD red-green-refactor cycle with a small example.

Save to ▾
Show answer
# Red: write a failing test first def test_discount(): assert discount(1000) == 100 # Green: simplest code that passes def discount(amount): return amount * 0.10 # Refactor: improve design, test stays green RATE = 0.10 def discount(amount): return round(amount * RATE, 2) Repeat the cycle for each new behaviour, such as no discount below 500.
21

An insurance premium depends on five Boolean conditions. The full decision table has 32 columns. How do you keep testing manageable?

Save to ▾
Show answer
First remove infeasible combinations, for example 'under 18' with 'retired'. Then minimise the table by merging columns where a condition has no effect on the action. Next, prioritise the remaining rules by risk and business value, testing high-impact rules first. I would also verify the rules with the business, since a large table often exposes contradictions or missing actions.
22

How do you report test status to non-technical stakeholders?

Save to ▾
Show answer
I focus on decisions they need to make. I use a short dashboard: overall status in plain words, coverage of key requirements, open critical defects and their business impact, top risks with mitigation, and what is needed from them. I avoid jargon, use simple charts and trends, and keep detailed data available for anyone who wants it. Different audiences may need different levels of detail.
23

Prepare a fault attack list for a file upload feature.

Save to ▾
Show answer
List likely failures and design tests for each: empty file; file just above the size limit; very large file; wrong extension; correct extension with wrong content; file names with spaces, Unicode or very long names; duplicate names; upload interrupted by network loss; many uploads at once; malicious files such as scripts; and uploads without login or with an expired session. Prioritise by risk.
24

Tell me about a time a test design technique helped you find a defect.

Save to ▾
Show answer
Situation: I was testing a scholarship form where students aged 17 to 25 were eligible. Task: design efficient tests for the age rule. Action: I applied boundary value analysis and tested 16, 17, 25 and 26. Result: 25 was wrongly rejected because the code used 'less than 25'. The developer fixed it, and I shared the BVA checklist with the team so others used it too.
25

A production hotfix must go live in three hours. How do you decide what to test?

Save to ▾
Show answer
I would do a quick impact analysis to see what the change touches, run confirmation tests for the defect, then a risk-based regression subset covering the changed module, its integrations and critical business flows like login and payment. I would use the automated smoke suite in the pipeline, record what was not covered, and plan fuller regression in the next regular release.
26

Ten automated tests fail overnight, but the cause is an expired SSL certificate in the test environment. How should this be reported?

Save to ▾
Show answer
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.
27

What are the coverage criteria for state transition testing?

Save to ▾
Show answer
All states coverage requires every state to be visited. Valid transitions coverage, also called 0-switch coverage, requires every valid transition to be exercised. All transitions coverage requires every valid transition to be exercised and every invalid transition to be attempted, ideally one invalid transition per test to avoid fault masking. Full valid transitions coverage guarantees full all states coverage, and all transitions coverage is recommended for safety-critical software.
28

How do you use impact analysis to decide regression scope?

Save to ▾
Show answer
Identify changed items from commits and change requests; use traceability to find affected requirements, components and interfaces; check dependency maps and defect history; rank the affected areas by risk; select automated regression for broad coverage plus targeted manual tests for high-risk flows; and document what is excluded and why. Impact analysis can also help decide whether a risky change should be made at all.
29

Your tests achieved 100 percent branch coverage, yet users reported a defect. How is that possible?

Save to ▾
Show answer
Coverage shows which code was executed, not that the code is correct or complete. The defect may come from a missing requirement that was never coded, which white-box testing cannot detect; from specific data values not used in tests; from integration or environment issues; or from wrong expected results. Coverage is a useful measure of thoroughness, but it must be combined with black-box and experience-based techniques.
30

Explain collaborative user story writing, the 3 Cs and INVEST.

Save to ▾
Show answer
User stories are written collaboratively by business, development and testing. The 3 Cs are Card (the medium describing the story), Conversation (how the story will be used, documented or verbal) and Confirmation (the acceptance criteria). A good story follows INVEST: Independent, Negotiable, Valuable, Estimable, Small and Testable. If stakeholders cannot say how to test a story, it is probably unclear or does not reflect real value.
31

What should a tester look for when reviewing code?

Save to ▾
Show answer
Check that inputs are validated and errors handled; comparisons at boundaries are correct, such as less than versus less than or equal; variables are initialised before use; there are no hard-coded passwords or secrets; logs avoid personal data; duplicated code is removed; complexity is reasonable; and unit tests cover new logic and edge cases. Combine manual review with static analysis tools for routine checks.
32

How would your test approach differ for a medical device versus a startup mobile game?

Save to ▾
Show answer
Testing is context dependent. For a medical device I would use formal documented plans, high independence, strict traceability to requirements, demanding coverage targets and evidence for regulators. For a mobile game I would use lightweight plans, exploratory testing, beta users, automation of core flows and fast releases. Factors that drive the choice include risk, regulations, budget, time, team skills, the SDLC and the technical environment.
33

Free shipping applies for orders of 499 rupees or more, otherwise a fee of 40 applies. Design tests using EP and BVA.

Save to ▾
Show answer
Partitions: 0 or less is invalid, 1 to 498 pays 40, and 499 or more ships free. EP tests: 0 rejected, 250 pays 40, 800 free. 2-value BVA adds 0 and 1 at the lower edge and 498 and 499 at the free shipping boundary. Combined minimal set: 0, 1, 250, 498, 499 and 800, each with the expected fee clearly stated.
34

What is the difference between testing and debugging?

Save to ▾
Show answer
Testing triggers failures caused by defects (dynamic testing) or finds defects directly in work products (static testing). Debugging is a development activity that reproduces a failure, diagnoses the root cause and fixes the defect. After the fix, testers run confirmation testing to check the fix and regression testing to check nothing else broke. In short, testing finds and reports problems, while debugging locates and removes them.
35

Which test estimation techniques are described in CTFL v4.0?

Save to ▾
Show answer
Estimation based on ratios uses historical figures, such as a development-to-test effort ratio. Extrapolation uses measurements from the current project, for example averaging the last three iterations. Wideband Delphi is an expert-based technique where experts estimate separately and iterate until consensus; Planning Poker is an Agile variant. Three-point estimation uses optimistic, most likely and pessimistic values to calculate a weighted estimate and its standard deviation.
36

Tell me about a time testing was squeezed at the end of a sprint. What did you do?

Save to ▾
Show answer
Situation: stories reached me only in the last two days of each sprint. Task: stop testing from being a bottleneck. Action: I proposed writing acceptance criteria and test cases during refinement, asked developers to merge smaller stories earlier, and automated API checks in the CI pipeline. Result: within three sprints, carried-over stories fell from five to one, and the team added early testing to its definition of done.

Companies with offices in Kolkata (2)

Frequently asked questions

Which companies hire ISTQB professionals in Kolkata?

Companies with large offices in Kolkata include Wipro, Cognizant. Use their company pages below to practise employer-specific sets.

Are ISTQB interviews in Kolkata different from other cities?

The questions depend more on the company than the city. Kolkata's mix of employers decides the style: Many openings are with service companies and their delivery centres, with a focus on strong fundamentals

How do I find ISTQB jobs in Kolkata?

Shortlist companies with Kolkata offices, keep your CV focused on ISTQB projects, apply on company career pages and job portals with the Kolkata filter, and practise the questions on this page before each interview.