Candidates describe a Fortinet Software Engineer process built around an online assessment, C or C++ coding, networking fundamentals, and manager or project conversations. Formats vary widely, and more reports end without an offer than with one.
$143K
Avg. Base Comp
$175K
Avg. Total Comp
3-5 rounds
Typical Rounds
2-6 weeks
Process Length
Fortinet's Software Engineer interviews, as candidates describe them, lean toward low-level, systems-flavored engineering more than a generic web-company loop. C and C++ come up repeatedly: candidates report coding in C, implementing a C++ singleton, discussing smart pointers, and answering object-oriented questions in C. Linked lists are the most repeated algorithm topic, including deleting a node, reversing every k nodes, and a variation that was not a straight copy of a well-known problem. Other reported coding questions include reversing a string, substring matching and reversing a binary tree.
Networking and security fundamentals are the second theme. Candidates mention TCP/IP, firewalls, inter-process communication, Linux, Git and Docker basics. One was asked to explain a TCP handshake in layman's terms, and another got a packet-stream design question about flagging an IP that sends more than 1,000 requests per minute.
Online assessments differ a lot from report to report. Examples include ten questions in 90 minutes with SQL and C#, a roughly two-hour mix of HTML/CSS, SQL, Bash, Git, Docker and algorithms, and a 14-question test that touched IPv4/IPv6 details. Preparing for breadth is safer than grinding only LeetCode.
Later rounds are less uniform. Some candidates describe very long blocks with paired interviewers, such as a four-hour session or two three-hour sessions in one day. Others describe a project deep dive, a hiring manager chat, or a demo and presentation. Several report weeks of silence after interviewing, so ask the recruiter about next steps at the end of each stage.
Synthesized from 20 candidate reports by our editorial team.
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Real interview reports from people who went through the Fortinet process.
I started with a Java Spring Boot take-home assignment that took a full day to complete. After submitting it, I got called in for what turned out to be a grueling series of interviews. The first round hit me with questions spanning multiple domains — they asked me to explain the diamond problem in Python, discuss many-to-many relationships, work through binary search and shortest path algorithms like Dijkstra's, and walk through my project experience. But that was just the beginning. I ended up doing a 5-hour take-home test and then went to their office for 3 consecutive interview sessions in a single day. One of those sessions was this bizarre 3-hour marathon starting with an exam-style test booklet supposedly created by their CTO. It was filled with random physics, probability, and mathematics questions mixed in with LeetCode-style coding problems. After working through the booklet, I met with interviewers to discuss my solutions and background. Then came the waiting game — I heard nothing for a month and a half before finally getting rejected, with no explanation. The whole thing left me frustrated. They clearly don't respect candidates' time, and the interview design felt chaotic and poorly coordinated. Between the take-home test, the five-plus rounds, and the extended silence, it was a rough experience.
Prep tip from this candidate
If you interview at Fortinet, expect a marathon process with multiple rounds spanning take-home assignments, a potentially lengthy technical test covering math/physics concepts alongside coding, and in-person sessions. Be ready for algorithm questions like binary search and graph traversal, but also brush up on system design concepts like many-to-many relationships and Python fundamentals like the diamond problem. Mentally prepare for a long waiting period afterward.
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Sourced from candidate reports and verified by our team.
Topics based on recent interview experiences.
Featured question at Fortinet
Write a function `sorting` from scratch to sort a list of strings in ascending alphabetical order
| Question | |
|---|---|
| Binary Tree Conversion | |
| DDoS Attack Response | |
| Employee Benefits Outreach | |
| Client Solution Pushback | |
| Your Strengths and Weaknesses | |
| Singly Linked List | |
| 2nd Highest Salary | |
| Merge Sorted Lists | |
| Weighted Keys | |
| Prime to N | |
| Largest Salary by Department | |
| Hurdles In Data Projects | |
| Bagging vs Boosting | |
| Flatten N-Dimensional Array to 1D Array | |
| String Subsequence | |
| P-value to a Layman | |
| Get Top N Frequent Words | |
| Groups of Anagrams | |
| Cyclic Detection | |
| Longest Increasing Subsequence | |
| Skyscanner Partner ETL | |
| Valid Anagram | |
| Term Frequency | |
| Complete Addresses | |
| Find Duplicate Numbers in a List | |
| Swapping Nodes | |
| Centralized Event Ingestion | |
| Cumulative Sales By Product | |
| Factorial Trailing Zeroes |
Synthesized from candidate reports. Individual experiences may vary.
Several candidates report an initial phone call with a recruiter or HR, covering background, education, the role and sometimes salary expectations. One describes it as about twenty minutes, and another as mostly behavioral. It typically appears to be a fit check before any technical work, so have a short story about your recent projects ready.
Candidates report an online coding test, often on HackerRank, but the content varies. Reports include ten questions in 90 minutes with SQL and C#, a roughly two-hour mix of HTML/CSS, SQL, Bash, Git, Docker and algorithms, and a 14-question test with IPv4/IPv6 details. Some mention multiple-choice questions on networking or web basics alongside coding, so prepare for breadth.
Candidates describe technical interviews centered on coding in C or C++, with linked list problems, string manipulation, tree problems and OOP concepts such as a singleton. Some report networking questions on TCP/IP, firewalls or TCP handshakes, and one recalled a packet rate-limiting design question. Session length varies from short blocks to multi-hour blocks with two interviewers, so stamina and explaining your reasoning aloud may matter.
Later stages reported by candidates include a hiring manager discussion, a project deep dive or demo, and behavioral questions about disagreements, career goals or fit. One senior-level candidate describes an executive presentation, and another describes a take-home design project. Tone varies by report, from relaxed to critical, so be ready to defend project decisions and technology choices.
Outcomes in the reports are mixed. Some candidates received or accepted offers, but more describe no offer. Several report weeks of silence or no formal rejection, and one reports a role put on hold after the final round. Communication may be slow, so ask about timelines at each stage and follow up politely.
