Persistent Systems ISTQB Interview Questions & Answers
Curated interview practice questions with answers. These are practice scenarios, not a verified list of past interview questions.
About Persistent Systems hiring for ISTQB roles
Persistent Systems is an Indian technology services company focused on software product engineering, digital transformation, cloud and data services. It serves clients in banking, healthcare, life sciences and software. In India it hires for software engineers, quality engineers, data engineers and analysts, often through campus drives with coding-focused assessments.
For ISTQB roles, this Persistent Systems practice set focuses most on Defect and Configuration Management (5), White-Box, Experience and Collaboration-Based Testing (5), Static Testing (4), Managing the Test Activities (4). It has 14 easy, 14 medium, 2 hard questions, so you can start easy and work up to the harder ones.
Company type
IT services
Headquarters
Pune, India
Main India offices
Pune, Nagpur, Bengaluru, Hyderabad, Goa
Persistent Systems ISTQB interview process
Online assessment (aptitude + coding)
Technical round 1
Technical round 2
HR round
Typical pattern based on public candidate experiences. Rounds vary by role, team and year.
Solved for Persistent SystemsStart practicing
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A defect is logged as new or open, then triaged: it may be rejected, marked duplicate or deferred, or assigned for fixing. After the developer fixes it, it moves to awaiting confirmation testing. The tester re-tests; if it passes, the defect is closed, and if it fails, it is re-opened. Teams customise the workflow, but each status should have clear rules about who can move it and when.
02
What types of defects are typically found by static testing?
Requirements defects such as inconsistencies, ambiguities, contradictions, omissions and duplicates; design defects like inefficient database structures or poor modularisation; coding defects such as variables with undefined values, unreachable or duplicated code and excessive complexity; deviations from standards; incorrect interface specifications; security vulnerabilities like buffer overflows; and gaps in test coverage, such as missing tests for an acceptance criterion.
03
A new tester has no domain knowledge and no detailed test cases. How can checklists help, and what is the risk?
A checklist of high-level conditions, such as validations, error messages, navigation and security basics, gives the new tester structure and consistency while learning the domain. Each run can vary slightly, which increases coverage. The risk is that checklists wear out as developers learn to avoid listed defects, so the team should update them with new defect patterns and pair the tester with an experienced colleague.
04
Your defect tracker is full of duplicate defects from several testers. How do you fix this?
I would set up a short daily triage to merge duplicates and link them to one master defect. Testers should search existing defects by module and keywords before logging, and use clear titles in a standard format such as 'Module - action - result'. Defined components and labels make searching easier. Tracking duplicate rates also shows whether the guidance is working.
05
Which test estimation techniques are described in CTFL v4.0?
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.
06
What are entry and exit criteria? How do they relate to Definition of Ready and Definition of Done?
Entry criteria define preconditions for starting an activity, such as available resources, testware, a stable build and a test environment. Exit criteria define what must be achieved to finish, such as coverage reached, unresolved defect counts, defect density and passed tests. Running out of time or budget can also be a valid exit. In Agile, exit criteria are often called the Definition of Done and entry criteria for a story the Definition of Ready.
07
What categories of test tools does CTFL v4.0 describe?
Test management tools, static testing tools, test design and implementation tools, test execution and coverage tools, non-functional testing tools, DevOps tools such as CI/CD pipelines and build tools, collaboration tools, and tools supporting scalability and deployment standardisation such as virtual machines and containers. Any tool that assists testing counts, even a spreadsheet. Tools improve efficiency, quality and repeatability.
08
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.
09
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.
10
How should you answer 'select TWO' questions in the CTFL exam?
Read the instruction carefully, because you must select exactly two options and usually get the point only if both are correct. Evaluate each option separately as true or false against the syllabus. Eliminate absolute statements and options that describe a different concept. If you are sure of one, compare the remaining options carefully. These questions appear in the exam, so practise them in sample papers.
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.
It is a misconception that verifying software thoroughly and fixing every found defect guarantees success. A system can pass every test against its specification and still be useless if the specification was wrong or the users' real needs were missed. That is why testing must include validation as well as verification, for example early review of requirements with business stakeholders and user acceptance testing before release.
13
A tester logs a defect titled 'Login broken' with no other details. How would you improve it?
A better title is 'Login - valid credentials - error 500 after clicking Sign in'. The report should add the build number and environment, browser and device, preconditions such as user type, numbered steps, test data used, expected result, actual result with the error message, a screenshot or log, severity, suggested priority, and a reference to the related test case. This lets a developer reproduce it immediately.
Test analysis answers 'what to test': it analyses the test basis, identifies testable features, defines and prioritises test conditions, and evaluates the test basis for defects. Test design answers 'how to test': it turns test conditions into test cases, identifies coverage items, defines test data requirements and designs the test environment. Example: the condition 'login with a locked account' becomes, in design, a case with exact inputs and the expected error message.
15
What does 'defects cluster together' mean and how is it used?
A small number of components usually contain most of the defects or cause most operational failures, similar to the Pareto principle. Predicted and observed defect clusters are an important input to risk-based testing, so testers focus more effort on those areas. Example: in a banking app, the interest calculation and payment modules may hold most reported defects, so they get deeper and more frequent regression coverage.
16
What is the difference between a test progress report and a test completion report?
A test progress report is produced regularly during testing, for example daily or per sprint. It covers the period, progress against plan, impediments, metrics, new or changed risks and planned work. A test completion report is prepared at the end of a test level, iteration or project. It summarises testing, evaluates quality against the plan, lists deviations, unmitigated risks, open defects, metrics and lessons learned.
Static testing detects defects in the earliest phases, when they are cheapest to fix. It finds defects that dynamic testing cannot, such as unreachable code or defects in non-executable work products. It helps evaluate quality and build confidence, improves shared understanding among stakeholders, and gives fast feedback on code through static analysis in CI. Reviews cost effort, but the total cost of quality is usually lower.
18
How do you prioritise risks using a likelihood and impact matrix?
Score each risk for likelihood and impact on a scale such as 1 to 5, and multiply to get the risk level. Example: wrong interest calculation, likelihood 3 and impact 5, level 15; slow report export, likelihood 4 and impact 2, level 8; spelling errors, 4 and 1, level 4. Test the highest levels first and most deeply, using more rigorous techniques and earlier test execution.
19
Which review type would you choose for safety-critical requirements, and why?
I would choose an inspection: a formal process with a trained moderator, defined roles, checklists, mandatory preparation, entry and exit criteria and collected metrics. Its aim is to find as many anomalies as possible and to provide documented evidence for audits. For a quick internal design idea, a walkthrough or informal review is enough, because the higher cost of inspection is justified only by high risk.
20
What do the K-levels K1, K2 and K3 mean in the CTFL syllabus?
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.
21
Testing found 80 defects and users found 20 more after release. What is the defect detection percentage?
DDP = defects found in testing / (defects found in testing + defects found after release) x 100
= 80 / (80 + 20) x 100
= 80 / 100 x 100
= 80 percent
So testing caught 80 percent of known defects. Tracking DDP across releases shows whether test effectiveness is improving.
A defect report gives the people responsible for handling and resolving the defect enough information to fix it. It also provides a way to track the quality of the work product, and it offers ideas for improving the development and test processes. A good report is clear, reproducible and neutral in tone, so that developers can act on it quickly and managers can analyse trends.
23
The requirements are incomplete and release is in two days. How do you test?
I would use session-based exploratory testing. I would write short charters for the riskiest areas, agree priorities with the product owner, run time-boxed sessions, note defects and questions, and debrief after each session. I would add error guessing for common failure types and a quick checklist for critical flows, and report clearly which areas were covered and which risks remain.
24
Explain equivalence partitioning and its coverage.
Equivalence partitioning divides data into partitions whose values are expected to be processed the same way, so one value per partition is enough. Partitions can cover inputs, outputs, configuration items or time, and include valid and invalid partitions. They must be non-empty and must not overlap. Coverage is partitions exercised divided by partitions identified. With several inputs, Each Choice coverage requires every partition of every input to be used at least once.
25
Why does 100 percent branch coverage guarantee 100 percent statement coverage, but not the other way round?
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.
26
A field accepts integers from 1 to 99. Which set of values achieves 100 percent 2-value BVA coverage: {1, 99}, {0, 1, 99, 100}, {0, 50, 100} or {1, 2, 98, 99}?
The answer is {0, 1, 99, 100}. Two-value BVA needs each boundary value and its closest neighbour in the adjacent partition: 0 and 1 at the lower edge, 99 and 100 at the upper edge. {1, 99} misses the invalid neighbours, {0, 50, 100} misses 1 and 99, and {1, 2, 98, 99} stays inside the valid partition, which is closer to 3-value thinking.
27
What is testware? Give examples from different test activities.
Testware is any work product created during the test process. Examples: test plan and risk register from planning; progress reports and control directives from monitoring and control; prioritised test conditions from analysis; test cases, test charters and coverage items from design; test procedures, automated scripts, test suites and test data from implementation; test logs and defect reports from execution; and the test completion report with lessons learned from completion.
28
What is exploratory testing and when is it most useful?
In exploratory testing, tests are designed, executed and evaluated at the same time while the tester learns about the test object. It is often structured as session-based testing with a time box, a test charter and a debrief. It is most useful when specifications are few or poor, under time pressure, or to complement formal techniques. Its success depends on the tester's experience, domain knowledge, curiosity and analytical skills.
29
An insurance premium depends on five Boolean conditions. The full decision table has 32 columns. How do you keep testing manageable?
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.
30
Show the TDD red-green-refactor cycle with a small example.
# 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.
Tips to crack the Persistent Systems ISTQB interview
Practise coding problems of easy to medium difficulty, as Persistent assessments usually focus more on programming than service peers.
Revise data structures, OOP, DBMS and operating system basics for the technical rounds.
Read about Persistent's product engineering background and its partnerships with major cloud providers.
Keep a one-minute story ready for every project on your CV: problem, your part, tools, result.
Practise the hard questions on this page aloud; Persistent Systems interviewers usually ask follow-ups on your first answer.
Frequently asked questions
How many rounds are there in the Persistent Systems ISTQB interview?
Candidates usually go through 4 stages: Online assessment (aptitude + coding); Technical round 1; Technical round 2; HR round. The exact rounds change with the role, team, location and your experience, so confirm the process with the recruiter.
Which topics should I prepare for the Persistent Systems ISTQB interview?
This practice set leans on Defect and Configuration Management (5), White-Box, Experience and Collaboration-Based Testing (5), Static Testing (4), Managing the Test Activities (4). Revise those first, then practise explaining one or two of your own projects end to end, because most Persistent Systems interviewers ask you to walk through real work.
Are these the exact questions asked at Persistent Systems?
No. These are curated practice questions that match the skills and difficulty usually tested in it services interviews like Persistent Systems's. They are not a leaked or verified list of past questions.
Where does Persistent Systems hire ISTQB professionals in India?
Persistent Systems has large teams in Pune, Nagpur, Bengaluru, Hyderabad, Goa. Openings and locations change often, so check the Persistent Systems careers page and filter by city and experience.