2026 Zscaler India Campus SDE Prep: 37 Past OA / Interview Experiences (Part 2 :)

Continued from Part 1.

Coverage: Detailed timelines 03–09. These reports are from 2023–2025 India campus hiring and cover SDE, Java, Dev C, C/C++, and Associate Software Engineer roles.

36 detailed candidate timelines, loops, and screens — continued

03: 2025 SDE summer intern — mixed-language OA, C++ depth, and two values rounds

Report date: April 3, 2025 · Role: SDE Summer Intern · Process: On-campus · Result: Not selected

Online assessment — 90 minutes

1. Four DSA problems. Two had to be solved in Python and two in C or C++.
2. The saved tasks were a grid shortest-path problem, an array problem using a greedy profit idea, and a client-server network task using a priority queue.
3. The report calls the grid solution DFS but does not publish the full movement and weight rules.
4. The candidate submitted just before time ran out.
5. Around 350–400 students took the test. Sixteen advanced.

Technical interview — about 60 minutes, HackerRank CodePair plus video

1. Explain OOP and its four main ideas.
2. Implement runtime polymorphism in C++. The candidate ran the code successfully, and the interviewer accepted it.
3. Explain when a vtable is created, memory management, and virtual destructors. The candidate could not remember enough about virtual destructors.
4. Code Merge Intervals. The candidate reported O(n log n) time and O(1) extra space. The solution ran.
5. Explain a two-pointer solution for Three Sum to a target. Time ran out before coding, but the interviewer accepted the approach.

Zscaler Values round — about 30 minutes

1. Introduce yourself and talk through your college journey.
2. Explain academic and personal projects: the problem, the approach, and the candidate’s role.
3. Give examples about leadership, teamwork, and solving a hard problem.

Final HR/campus discussion — about 25 minutes

1. Discuss the candidate’s background and college experience.
2. Explain what they would change at their institute to reduce the gap between college and industry.
3. Discuss general industry trends.

Three candidates reached the end. One was selected.

04: 2024 Java intern — nine-question OA and three Java-heavy interviews

Interview date: May 2024 · Role: Java Developer Intern · Process: On-campus · Result: Drive cancelled

The same drive offered C Developer, Python Developer, and Java Developer roles. This candidate chose Java.

Online assessment — 120 minutes

1. One medium greedy DSA problem, restricted to Java.
2. One Java programming task that required implementing supplied interfaces.
3. Two medium SQL tasks using joins, sorting, grouping, and limits.
4. Five questions on aptitude, OOP, and DBMS.
5. Twelve candidates were shortlisted.

Technical interview 1 — 30 minutes, Java only

1. Balanced Brackets. The candidate explained the logic and coded it.
2. A string-manipulation problem. The full prompt was not saved.
3. A SQL query using joins and grouping. The candidate said this was harder than the two coding tasks.
4. Ten days later, the candidate learned they had passed.

Technical interview 2 — 45 minutes, Java only

1. An easy greedy problem, solved and coded in about two minutes.
2. A CSES Coin Problem variant. The candidate drew a recursion tree, explained the recursive DP, coded it, and discussed time and space.
3. KMP string matching, explained and coded in about ten minutes.
4. A range-DP problem. The candidate explained the idea; the interviewer did not require code.
5. The final 15 minutes were rapid-fire Java: interfaces, abstract classes, inheritance, overload/override, diamond problem, functional interfaces, threads, synchronized blocks, semaphores, Singleton variants, and exception handling.
6. The candidate had stumbled during the introduction. The interviewer let them pause and start again.

Managerial/technical round — 45 minutes

1. Solve a medium String + Graph problem.
2. The first solution was O(n³). After discussion, the candidate improved it to O(n²) and wrote the solution in C++.
3. Explain why a Data Science and AI student wanted a Java Developer role.

Three of the twelve shortlisted students reached this round. Zscaler later cancelled the campus drive.

05: 2024 Dev C — a disguised binary-search problem and a failed bit optimization

Report date: October 2024 · Role: Dev C Intern + FTE · Process: On-campus · Result: Rejected

The drive offered Dev C, Dev Java, and Dev Python. The candidate chose Dev C because they had coded in C++ for a long time.

Online assessment

1. Three HackerRank coding questions.
2. The candidate remembered a 120-minute limit but did not save the prompts.
3. Results took about 10–12 days. Each role had its own shortlist.

Technical interview 1

1. Use the provided online IDE and its tests.
2. Reorder a linked list so nodes at even positions come before nodes at odd positions.
3. The candidate clarified that “even” meant node position, not the stored value. They also asked about an empty list and a one-node list.
4. Search a rotated sorted array. The interviewer did not name the standard problem; the candidate had to recognize the structure.
5. Explain destructors, operator overloading, and how constructors are called.
6. Given base and derived classes with constructors and destructors, give the exact call order when a derived object is created.
7. Explain deadlock conditions, race conditions, process versus thread, the OSI model, and virtual functions.
8. The candidate could not fully explain virtual functions, but felt the interviewer was helpful and satisfied overall.

Technical interview 2

1. Given 4 (0100) and 3 (0011), find the bit positions where they differ and return the sum of those positions. The report uses positions 0, 1, and 2, so the example result is 3.
2. The candidate used XOR in a brute-force attempt. Only two tests passed, and they did not find the optimized method.
3. For every value in array A, count how many values in array B are less than or equal to it.
4. Only the approach was required. After 10–15 minutes, the candidate reached sorting plus binary search.
5. Explain TCP, UDP, and DNS.

The candidate was rejected. The report also says the hiring process stopped soon afterward.

06: 2024 Developer C — four OA topics and three technical interviews

Report date: June 2024 · Role: Developer C Intern · Process: On-campus · Result: Selected

Online assessment

The report lists four areas but not full prompts:

1. An implementation task using HashMaps.
2. Trie.
3. Greedy using a Heap.
4. DP based on Longest Increasing Subsequence.

Interview 1

1. C pointer questions.
2. Find the array value that occurs an odd number of times.
3. Find the GCD of all array values, then sum all positive divisors of that GCD.
4. Merge Intervals.

Interview 2

1. Ten to fifteen questions on Operating Systems.
2. Ten to fifteen questions on Computer Networks.
3. Ten to fifteen questions on C.
4. Longest Common Subsequence of two strings.

The report does not list the individual OS, CN, or C questions.

Interview 3

1. Implement Run-Length Encoding.
2. Use C only.

07: 2023 Intern + FTE — three long interviews across networks, OOP, and coding

Report date: September 2024 · Interview cycle: Fall 2023 · Role: Intern + FTE · Process: On-campus · Result: Selected

Online assessment — 2 hours

1. Four DSA questions on HackerRank.
2. The report does not publish the prompts.

Interview 1 — 1 hour 10 minutes

1. Compare personal and enterprise VPNs. Explain tunneling, encryption, and authentication.
2. Compare IPv4 and IPv6, including addressing and use cases.
3. Walk through OSI, DNS, and DHCP.
4. Explain denial-of-service attacks and asymmetric encryption.
5. Explain smart pointers and how they help prevent leaks.
6. Coding task: generate palindromes from two strings, combine them, and choose the longest result; use lexicographic order for ties.
7. The candidate first misunderstood the coding problem and used too much time. The interviewer had planned a second DSA problem but could not ask it.
8. The interviewer was impressed by the smart-pointer answer.

Interview 2 — 1 hour 45 minutes

1. A request gets no response. Decide whether the machine is down or only the port failed.
2. The candidate proposed reverse proxy and load-balancer tracking. The interviewer’s answer was traceroute.
3. Use pointer arithmetic to inspect whether a certain byte is set. The candidate suggested changing the pointer type and moving one byte but could not make it precise. The interviewer suggested a byte-sized type such as uint8_t.
4. Explain ARP in depth.
5. Explain the TCP three-way handshake, then extend the answer to TLS.
6. Compare TCP and UDP and give fitting use cases.
7. Implement inheritance, polymorphism, virtual functions, overloads, and dynamic binding. The interviewer changed the scenarios and pressed for exact explanations.
8. Solve a problem similar to Asteroid Collision. The changed rules were not saved.
9. Count length-n vowel strings under adjacency rules such as a only after e and e only after i. The full transition table was not saved.
10. The candidate said they first gave overcomplicated answers, then settled down and recovered.

Interview 3 — 1 hour 30 minutes

1. Compare HTTP and HTTPS. Explain TLS key exchange, authentication, and session encryption.
2. Explain who calls main and walk through preprocessing, compilation, assembly, linking, and execution.
3. Compare processes and threads. Discuss both process and thread scheduling. Explain why a normal function call does not create a new thread.
4. Draw the memory layout of a process: code, data, heap, and stack.
5. Explain abstraction and other OOP ideas, why OOP may be preferred to procedural code, and the limits of procedural code.
6. Work through a queue/log analysis task and a string-subsequence discussion. The report does not preserve the full prompts.

08: 2023 C/C++ intern + FTE — deep C internals and custom malloc

Offer date: November 16, 2023 · Role: Software Developer C/C++, six-month internship + FTE · Location: Bengaluru · Process: On-campus · Result: Accepted offer

Online assessment — 90 minutes

1. BFS plus Binary Search.
2. DP on Trees. The candidate used the centroid of the tree.
3. Segment Tree plus Binary Search.
4. The candidate solved the first two and ran out of time on the third.
5. The shortlist took about 40–50 days.

Technical interview 1 — about 80 minutes

1. The interviewer opened with a casual breakfast question, then asked the candidate to rate their C and C++ skills.
2. Cover auto, extern, static, and register in depth: scope, lifetime, and storage.
3. Explain dynamic allocation and stack versus heap.
4. Explain how realloc works. The candidate reasoned that the block may need a new base address because growing in place could overlap another allocation.
5. Compare struct and union. Calculate the sizes of two supplied structs. Explain padding using processor word size and memory-access efficiency.
6. Cover pointer arithmetic, dangling pointers, void pointers, and volatile.
7. Answer quick OS questions on races, semaphores, paging, and thrashing.
8. Discuss SSL, certificates, TCP handshake and flags, DNS, and public/private-key encryption.
9. Code a C string-pattern matcher. The candidate gave and coded an O(n²) brute-force solution, then explained Rabin–Karp as the optimization.
10. Roughly 45–50 minutes went to core concepts and 15–20 minutes to coding.

Technical interview 2 — about 75 minutes

1. Compare arrays and linked lists using real use cases.
2. Prove the time complexity of binary search.
3. Give a mathematical proof for Floyd’s cycle detector.
4. Explain C++ unordered_map: hashing, collision chains, and rehashing.
5. The interviewer then used a small bucket count, removed rehashing, and asked for O(log n) insert/search.
6. The candidate reasoned toward an array of binary-search trees. The intended direction was ordered maps and red-black trees.
7. Explain gateways, routing versus switching, MAC addresses, NICs, ARP, subnets, subnet IDs, CIDR, and SSL’s four-phase handshake.
8. Implement custom malloc and free in C. The candidate had not seen the task. With one or two hints, they produced what they described as an O(1) solution.
9. The interviewer accepted the code.

09: 2024 Associate Software Engineer — two OA problems and runnable live code

Interview date: June 2024 · Role: Associate Software Engineer · Location: Bengaluru · Process: Campus placement · Result: Accepted offer

1. HackerRank had two coding questions: one Tree problem and one 2D Matrix problem.
2. The matrix task was described as similar to a Google Kick Start problem. The exact prompt was not saved.
3. Interviews covered DSA, Computer Networks, and Operating Systems.
4. The candidate had to write code that compiled and ran.

Part 3 continues with timelines 10–16.