Zscaler Backend Engineer interview questions and process

Updated 16 Oct 2026 · 13 sources

Hiring Pulse: where Zscaler candidates are right now

Dated status reports from public Reddit threads and anonymous PortLume reports, updated Oct 18. Not official Zscaler data.

1 status reports in the last 7 days
Not enough data yet: median from final interview to a decision shows at 5+ people
Latest movement: no decisions reported lately

Latest Zscaler hiring reports

Oct 17: Applied Oct 11 (r/Btechtards)

Candidates rate the Zscaler Backend Engineer interview Medium-Hard: Reports mix core DSA with from-scratch implementations (priority queue, hashmap), networking and TLS depth, and detailed project grilling across multiple rounds. Reports describe 5 rounds, from Recruiter screen and online/initial technical round to Round 4: Project deep-dive and senior/hiring manager discussion.

Difficulty: Medium-Hard
Estimated salary: roughly Rs 11 LPA fixed at 1 year experience, around Rs 34 LPA fixed at 5 years for backend roles in India
Skills asked about: Data structures and algorithms, Java or C++, Networking (TCP/UDP, TLS, PKI)

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Zscaler Backend Engineer interview rounds

Recruiter screen and online/initial technical round: Initial screen to match your experience to the team. A first technical round can end the process early if the DSA problem is not solved in the interviewer's preferred language.
Round 1: DSA and language fundamentals
Round 2: Networking and security concepts plus coding
Round 3: Data structure implementation from scratch
Round 4: Project deep-dive and senior/hiring manager discussion

Questions reported in Zscaler Backend Engineer interviews

Solve a priority queue with comparator problem (in Java specifically)
TCP vs UDP, and explain packet flow in a network with a detailed example
Discuss IPC mechanisms and multithreading issues, including familiarity with pthread APIs
Discuss approaches for 2Sum and k largest elements in an array
Write complete code to remove the kth node from the end of a linked list
Implement a priority queue for structs from scratch

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Zscaler Backend Engineer interview: quick answers

How many rounds are in the Zscaler Backend Engineer interview?

Public reports describe 5 rounds for the Zscaler Backend Engineer interview: (1) Recruiter screen and online/initial technical round, (2) Round 1: DSA and language fundamentals, (3) Round 2: Networking and security concepts plus coding, (4) Round 3: Data structure implementation from scratch, (5) Round 4: Project deep-dive and senior/hiring manager discussion.

Is the Zscaler interview difficult?

Public reports put the Zscaler Backend Engineer interview at Medium-Hard difficulty. Reports mix core DSA with from-scratch implementations (priority queue, hashmap), networking and TLS depth, and detailed project grilling across multiple rounds. The process has 5 rounds, from Recruiter screen and online/initial technical round to Round 4: Project deep-dive and senior/hiring manager discussion.

Does Zscaler ask DSA in Backend Engineer interviews?

Some, but reports say it is not the main focus. Coding reported includes realloc and substring search, so this is closer to systems-level work than pure LeetCode. Rounds that involve coding: Round 1: DSA and language fundamentals, Round 2: Networking and security concepts plus coding, Round 3: Data structure implementation from scratch.

What is the Zscaler Backend Engineer salary in India?

Estimated from public salary data: Roughly Rs 11 LPA fixed at 1 year experience, around Rs 34 LPA fixed at 5 years for backend roles in India. This is not an official Zscaler figure, and pay varies by level, city and experience.

Sources

Based on 13 public reports: LeetCode Discuss (6), Blind (2), Glassdoor (2), Levels.fyi (1), Weekday (1), YouTube (1), last updated Oct 2026.

Compiled by Adarsh Sharma from public candidate reports. Unofficial guide: PortLume AI is not affiliated with Zscaler.

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