201 questions from 30 interviews · updated from reports 2016-2024
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PwC is a professional services network that provides audit, tax, consulting, and advisory services to businesses and public sector clients. In India, it hires for technical roles such as technology consultant, associate, cyber security analyst, data analyst, and software or cloud engineering roles.
The roles that come up most are Technology Consultant, Associate and Cyber Security Analyst. This covers 30 candidate interviews reported from 2016 to 2024. Most sat it at entry level (24 of 30 that recorded a level), with 4 internship interviews alongside. Among the 25 that recorded either route, arrivals split between campus drives (21, 84%) and off-campus applications (4, 16%). Most questions fall under CS fundamentals and Behavioural.
Ans. Pick a specific situation where you influenced others without relying only on authority, such as leading a project, resolving conflict, or guiding a struggling team. Emphasise the goal, your actions, how you communicated, and the result. Interviewers listen for ownership, judgement, empathy, accountability, and measurable impact.
Ans. Object-Oriented Programming models software as objects that combine data and behaviour. The main concepts are encapsulation, which hides internal state; abstraction, which exposes only needed details; inheritance, which reuses and extends existing classes; and polymorphism, which lets different objects respond to the same interface in their own way.
Ans. A stack removes the most recently added item first, while a queue removes the earliest added item first. This is usually called LIFO for stack and FIFO for queue. Stacks are used for function calls, undo, or parsing. Queues are used for scheduling, buffering, and breadth first search.
Ans. SSL, now largely replaced by TLS, secures a connection between an application and a server using certificates, key exchange, encryption and integrity checks. A VPN secures all or selected network traffic by creating an encrypted tunnel to a VPN server. SSL protects sessions, while a VPN protects network paths.
Ans. PARTITION BY divides a query result into groups for a window function to operate on independently. It is used with OVER, for example to rank rows or calculate totals within each customer, department, or category. Unlike GROUP BY, it does not collapse rows; each original row remains in the result.
Ans. A man-in-the-middle attack is when an attacker secretly intercepts communication between two parties and may read, alter, or inject messages while both sides believe they are talking directly. The key risk is loss of confidentiality and integrity, commonly prevented with strong authentication, TLS certificates, and checking certificate validity.
Ans. Deadlock is a state where two or more processes are permanently blocked because each is waiting for a resource held by another process. The key point is that none can continue without external intervention. It typically requires mutual exclusion, hold and wait, no preemption, and circular wait to occur.
Ans. Strong C++ understanding means knowing object lifetime, memory ownership, value versus reference semantics, and polymorphism. The most important detail is RAII: resources should be acquired in constructors and released in destructors, usually through standard library types such as smart pointers, so code stays safe even when exceptions occur.
Ans. Use backtracking with include or exclude choices for each element, carrying the current subsequence and its sum. When the index reaches the end, output the subsequence if the sum is K. The data structure is a temporary list or array. Time complexity is O(2^n), excluding the cost of printing results.
Ans. I would secure a corporate network with defence in depth: strong identity, network segmentation, least privilege access, hardened endpoints, monitored gateways, patching, backups and incident response. The most important detail is to assume compromise and limit blast radius using zero trust controls, MFA, conditional access, logging, EDR and strict separation of critical systems.
Ans. Penetration testing methodologies are structured ways to assess security by simulating real attacks within agreed scope. Common phases are planning, reconnaissance, scanning, vulnerability analysis, exploitation, post-exploitation, reporting, and retesting. The key detail is control: tests must be authorised, repeatable, evidence-based, and focused on business risk, not just finding technical flaws.
Ans. Empowerment should be internal, though external support can help create the conditions for it. The key idea is that real empowerment comes from self-belief, ownership and the ability to act independently. For such questions, identify the core meaning of the word, then choose the option that best fits its natural source or direction.
Ans. Remove all leaf nodes by traversing the tree recursively and returning null whenever a node has no left or right child. Use postorder processing so children are handled before deciding what each parent should keep. The BST property is not needed. Time complexity is O(n), with O(h) recursion stack space.
Ans. Network security is based on confidentiality, integrity and availability, supported by authentication, authorisation, least privilege and defence in depth. The key detail is that controls should be layered: encryption protects data, firewalls and segmentation limit access, monitoring detects attacks, and patching reduces known weaknesses before they are exploited.
Ans. Software vulnerabilities are weaknesses in software design, implementation, configuration, or dependencies that attackers can exploit to affect confidentiality, integrity, or availability. Common examples include injection, broken authentication, buffer overflows, insecure access control, and outdated libraries. The most important defence is preventing them early through secure design, review, testing, patching, and least privilege.
Ans. A strong answer treats 70 hours as a short-term exception, not a normal operating model. Pick a high-stakes deadline or incident, and emphasise prioritisation, communication, recovery time, and protecting quality. Interviewers listen for commitment without martyrdom, awareness of burnout, respect for team sustainability, and willingness to challenge poor planning.
Ans. Normalization forms reduce redundancy and update anomalies by organising tables around keys and dependencies. 1NF makes values atomic. 2NF removes partial dependency on part of a composite key. 3NF removes transitive dependency on non-key attributes. BCNF strengthens this so every determinant is a candidate key. Higher forms handle multivalued and join dependencies.
Ans. SQL injection is an attack where untrusted input is treated as part of an SQL command, allowing an attacker to read, change, or delete data. Prevent it by using parameterised queries or prepared statements, so values are bound separately from SQL code. Also validate input and use least-privilege database accounts.
Ans. Normalization is organising relational tables to reduce redundancy and avoid update, insert and delete anomalies. 1NF removes repeating groups, 2NF removes partial dependency on a composite key, 3NF removes transitive dependency, BCNF requires every determinant to be a candidate key, 4NF removes multivalued dependencies, and 5NF removes join dependencies.
Ans. A thread is the smallest unit of execution inside a process. Threads in the same process share code, data, heap and files, but each has its own stack and registers. Diagram: Process [shared memory/resources] contains Thread 1 [stack], Thread 2 [stack]. Example: a browser uses separate threads for UI, networking and rendering.
Ans. 2-tier architecture has a client layer that talks directly to the database, while 3-tier architecture separates the system into client, application or business logic, and database layers. The key difference is that 3-tier centralises business logic in a middle tier, improving scalability, security, maintainability, and reuse compared with direct client to database access.
Ans. Scan the array once while keeping two values: highest and second highest. For each element, update highest and move the old highest to second highest, or update only second highest if the element lies between them. This uses no extra data structure, runs in O(n) time and O(1) space.
Ans. Emerging cybersecurity trends show that defence is becoming more automated, identity-focused, and risk-based. The most important shift is the use of AI by both attackers and defenders, which makes rapid detection, strong access control, secure software supply chains, and continuous monitoring essential rather than optional.
Ans. Choose a real incident where priorities changed quickly and the impact was clear. Emphasise triage by risk, containment first, evidence preservation, clear ownership, and regular communication with stakeholders. Interviewers listen for calm judgement, structured decision making, business awareness, and the ability to balance speed with accuracy under pressure.
Ans. Secure cloud environments with strong identity controls, least privilege access, network segmentation, encryption, logging, patching, and continuous monitoring. The most important detail is to treat identity as the main security boundary: use MFA, short-lived credentials, role-based access, regular access reviews, and automated detection of suspicious permission changes.
Ans. Linux commands are text instructions used in a shell to manage files, processes, users, networking and system resources. Common examples include ls, cd, grep, chmod, ps and top. Data ingestion is the process of collecting data from sources and moving it into a storage or processing system, either in batches or streams.
Ans. Use recursion: create a function that takes a current number, prints it, and calls itself with the next number until it passes 100. No extra data structure is needed, only the call stack. The time complexity is O(100), effectively O(1) for this fixed range, and stack space is O(100).
Ans. Group the table by the salary column and return only groups whose row count is greater than one. This finds salary values shared by multiple employees. The database uses grouping, typically via a hash aggregate or sort aggregate, and the expected time is linear with hashing or n log n with sorting.
Ans. A kernel is the core part of an operating system that manages hardware, memory, processes, devices and system calls. In a monolithic kernel, most services like drivers, file systems and networking run inside kernel space, giving high performance but weaker isolation. In a microkernel, only minimal core functions run in kernel space, improving reliability but adding communication overhead.
Ans. Use GROUP BY to aggregate rows by key columns, and JOIN to combine related tables through matching primary and foreign keys. For example, join customers to orders on customer id, then group by customer id to calculate total order value. The database uses indexed tables, hash joins or nested loops, typically O(n + m) with suitable indexes.
Ans. Cryptography secures systems by using mathematical techniques to protect data confidentiality, integrity and authenticity. Symmetric encryption is fast and uses one shared key, asymmetric encryption uses public and private keys for exchange and identity, hashes detect changes, and digital signatures prove origin. The most important detail is safe key management.
Ans. A final control element is the device that directly changes the process in response to the controller’s output. It is the last active part of the control loop, converting a control signal into physical action, such as opening a valve, moving a damper, or changing a pump or motor speed.
Ans. Use Java when I need strong typing, high performance, concurrency, and long-term maintainability in a large service; use Python when speed of development, scripting, automation, or data science matters more. The key trade-off is usually runtime performance and structure versus developer productivity and library convenience.
Ans. Merge sort recursively splits the array into halves, sorts each half, then merges two sorted halves using a temporary array. For [5, 2, 4, 1], split to [5, 2] and [4, 1], then [5], [2], [4], [1]. Merge to [2, 5] and [1, 4], then [1, 2, 4, 5]. Time complexity is O(n log n).
Ans. GDPR is a data protection law for handling personal data, while ISO 27001 is an international standard for managing information security. GDPR focuses on lawful processing, consent, rights, breach reporting and privacy by design. ISO 27001 requires a risk-based information security management system, with controls, audits and continual improvement.
Ans. A PID controller is a feedback controller that adjusts a process input to reduce the error between a desired setpoint and the measured output. It combines proportional action for current error, integral action for accumulated past error, and derivative action for predicted future change. Its role is to keep systems stable, accurate, and responsive.
Ans. A 3-tier Java application is split into presentation, business logic, and data access layers. The UI layer handles requests and responses, the service layer applies rules and transactions, and the DAO or repository layer talks to the database. The key benefit is separation of concerns, making the system easier to test, maintain, and scale.
Ans. Java is usually faster than Python because Java bytecode runs on a JVM with just in time compilation and strong runtime optimisation, while Python is typically interpreted and dynamically typed. Internally, Java source is compiled by javac into bytecode, loaded by the JVM, verified, executed, optimised into native machine code, and managed by garbage collection.
Ans. Incident response involves preparing, identifying the breach, containing it, eradicating the cause, recovering systems, and reviewing lessons learned. The most important detail is to preserve evidence while limiting damage, so actions should be logged, affected systems isolated, credentials rotated, stakeholders informed, and root causes fixed before normal service resumes.
Ans. Yes, and justify it with a concrete example where you linked your work to commercial value. Choose a situation involving cost, revenue, risk, efficiency, client impact, or market insight. Emphasise the trade-offs you considered, the data you used, and the outcome. Interviewers listen for curiosity, judgement, practicality, and client focus.
Ans. We use Power BI to turn data from many sources into clear dashboards, reports, and business insights. It is used for sales tracking, finance reporting, operations monitoring, and customer analysis. For example, a retail company can combine store sales, inventory, and marketing data to identify low-stock products, compare branch performance, and improve promotions.
Ans. Choose a real, low-drama conflict where you helped the team reach a practical outcome. Emphasise listening to both sides, separating facts from assumptions, keeping discussion respectful, and agreeing clear next steps. Interviewers listen for maturity, accountability, communication, and whether you solved the issue without blaming others or escalating unnecessarily.
Ans. Use a SELECT statement with an INNER JOIN, selecting the required columns from both tables and joining them on the matching key, such as a customer ID. For example, retrieve orders with customer names by joining Orders to Customers on their shared customer_id column. The key detail is the join condition, which links related rows correctly.
Ans. Select salaries from the employee table, order them by salary in descending order, and return only the first three rows. This gives the three highest salary records. If the requirement means top three distinct salary values, remove duplicates first or use a ranking function such as dense rank before filtering.
Ans. Encapsulation keeps an object’s data and behaviour together and controls access to its internal state. An interface defines what operations a type must provide, without saying how they work. Abstraction hides unnecessary implementation detail and exposes only the essential behaviour. Together, they reduce coupling and make code easier to change and test.
Ans. A PID controller keeps a system output close to a desired setpoint by adjusting the control input using proportional, integral, and derivative terms. The proportional term reacts to current error, the integral term removes accumulated steady-state error, and the derivative term predicts change to reduce overshoot and improve stability.
Ans. An interface is more efficient when you only need a contract for behaviour, not shared state or inherited implementation. It keeps classes loosely coupled and avoids forcing them into a common inheritance hierarchy. Runtime performance is usually not the main difference, since interface calls and polymorphic virtual calls are both dispatched dynamically in most languages.
Ans. Group rows by salary, count how many employees have each salary, sort those groups by the count in descending order, and return only the first three salary values. The key detail is tie handling: a simple limit returns any three among ties, while rank or dense rank includes all salaries tied in the top three frequencies.
Ans. Look for the rule that changes each item into the next. Check simple patterns first, such as adding, subtracting, multiplying, alternating steps, position changes, symmetry, or letter order. Split the sequence if needed into odd and even terms. Test your rule on every term before choosing the missing one.
Ans. I would solve it by choosing the simplest algorithm that meets the constraints, then explain the key data structure and why it is correct. For example, if repeated lookups are needed, I would use a hash map to store seen values. This usually gives O(n) time and O(n) space.
Ans. Supply chain management coordinates sourcing, production, inventory, logistics and delivery to meet demand at the lowest practical cost and risk. Planning matters most because forecasts, capacity, lead times and stock policies must align, otherwise businesses face shortages, excess inventory, poor service levels or higher operating costs.
Ans. Pick a situation where you improved security outcomes for stakeholders, such as risk assessment, incident response, compliance, or awareness. Emphasise practical advisory skills: understanding client needs, translating technical risk into business impact, and delivering usable recommendations. Interviewers listen for commercial awareness, collaboration, structured problem solving, and a clear interest in helping clients strengthen resilience.
Ans. A system call is the controlled interface through which a user program asks the operating system kernel to perform privileged services, such as creating processes or accessing files. fork() creates a new child process by duplicating the calling process. It returns 0 in the child, the child’s process ID in the parent, and -1 on failure.
Ans. Symmetric key encryption uses the same secret key to encrypt and decrypt data, while asymmetric key encryption uses a public key and a private key pair. The key difference is key management: symmetric encryption is faster but needs secure key sharing, while asymmetric encryption is slower but makes secure exchange and digital signatures easier.
Ans. Yes, the duck can escape if the fox is four times faster. The duck first swims in a small circle, staying opposite the fox. This is possible up to radius R/4, since its angular speed then matches the fox’s. From there it swims straight to the bank. The fox needs longer to run halfway round.
Ans. There is not enough information to give a unique order. I would place six positions in a row, assign P, Q, R, S, T and U, then translate each clue into positional rules, such as left of, next to, or not adjacent. Applying the rules step by step should leave one valid arrangement.
Ans. Common application security vulnerabilities are mitigated by defence in depth: validate input, encode output, use parameterised queries, enforce strong authentication and authorisation, apply least privilege, keep dependencies patched, and log security events. The most important detail is to treat all external input as untrusted and handle it safely at every boundary.
Ans. Start by scanning the paper and solving the quickest, most familiar questions first. Use approximation, elimination, ratios, percentages, and mental arithmetic to reduce calculation time. Skip any question that takes too long and return later. Track time in small blocks, avoid perfectionism, and always check units, signs, and answer options before marking.
Ans. Use a defence in depth methodology based on threat modelling and zero trust principles. Identify likely attack paths, then add layered controls such as least privilege, strong authentication, network segmentation, input validation, encryption, logging and monitoring. The most important detail is to assume one control can fail, so detection and containment must be built in.
Ans. Three weighings are enough for the classic 12 coin version, where the fake may be heavier or lighter. Each weighing has three outcomes, so three weighings give 27 outcome paths. There are 24 possibilities, 12 coins times heavy or light, so it is possible. Use a pre-planned balanced ternary decision tree to map each outcome to one coin and direction.
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Candidate interviews most often cover CS fundamentals (62%) and Behavioural (14%).
Candidate interviews show an average of 3.7 rounds per experience, with a typical sequence of Online test → Technical → HR. Individual interview paths can vary.
Among questions with a recorded difficulty, the mix is easy 53%, medium 44%, hard 4%.
