Fortinet software engineering interviews reported a mix of online assessments, recruiter conversations, C/C++ coding, networking fundamentals, and practical design discussions.
$145K
Avg. Base Comp
$175K
Avg. Total Comp
3 rounds
Typical Rounds
3-6 weeks
Process Length
Fortinet Software Engineer candidates describe a technical process that can span broad screening material and networking-oriented engineering conversations. C++ design and networking fundamentals recur across the available accounts, but the format is not uniform. One candidate began with an HR phone conversation about experience and education, then met three engineers together to implement and explain a singleton class; an unscheduled director conversation followed on smart pointers and related C++ concepts. That account emphasized code structure and design reasoning over running every solution live.
Other candidates reported online assessments before later interviews. One assessment mixed HTML/CSS, SQL, Bash, Git, Docker, and algorithm problems, while another candidate described algorithms and data structures followed by C++ coding and a packet-stream design question: detect when an IP exceeds 1,000 requests per minute. Technical discussions also covered C object-oriented programming, TCP, inter-process communication, firewalls, and basic data structures. Prepare to explain tradeoffs clearly, not just name concepts: for example, how a singleton is structured, when smart-pointer ownership changes, or how a time-windowed request counter handles incoming packets.
The evidence is limited and reports differ, so use the topic mix as preparation direction rather than a fixed sequence. Review any materials sent before an interview closely; one candidate said those materials were discussed directly. Reserve time for recruiter or manager conversations about your work, team fit, and career goals as well as the technical preparation.
Synthesized from 6 candidate reports by our editorial team.
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Real interview reports from people who went through the Fortinet process.
The most unusual part of my Fortinet process was that the technical interview was conducted by three engineers at once rather than split across several coding rounds. It began with a phone call with HR that felt primarily behavioral. We discussed my past work experience and education, with the goal of determining whether I matched what the engineering manager was looking for.
A couple of days later, I had a coding interview over Microsoft Teams with the three engineers. The conversation went fairly deep on C++, and they asked me to implement a singleton class and explain its uses. It was less about catching minor syntax details or getting a program to run live and more about how I approached the problem, structured the code, and reasoned through the design. I found that emphasis helpful, although I still made sure I could clearly justify my choices.
A few days after that, I got an unexpected call from the engineering director, who asked whether I had time to interview right then. I did, so we continued immediately. That discussion focused on smart pointers and related C++ topics. Overall, the process moved quickly and was strongly centered on practical C++ design and reasoning rather than a long sequence of algorithmic coding exercises. I received and accepted an offer. My main advice is to be ready to explain a singleton implementation and its tradeoffs clearly, then review smart pointers well enough to discuss them conversationally in an unplanned director call.
Prep tip from this candidate
Be prepared to implement and explain a C++ singleton class, including its uses, and review smart pointers and closely related C++ concepts. Expect the technical discussion to prioritize your reasoning and code structure over compiling or running every solution.
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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 | |
| Valid Anagram | |
| Complete Addresses | |
| Term Frequency | |
| Find Duplicate Numbers in a List | |
| Swapping Nodes | |
| Centralized Event Ingestion | |
| Factorial Trailing Zeroes | |
| Cumulative Sales By Product | |
| Target Indices |
Synthesized from candidate reports. Individual experiences may vary.
Several candidates reported an online assessment before later interviews. The reported content varied substantially: one described algorithms and data structures, while another described a roughly two-hour HackerRank assessment with web fundamentals, SQL, Bash, Git, Docker, and algorithm problems.
Candidates report an early recruiter or HR conversation focused on the role, team, experience, education, and fit. One account characterized this as behavioral; prepare concise examples from past work and questions about the engineering role.
Technical formats varied by candidate. Reported topics include implementing and explaining a C++ singleton, smart pointers, C coding, data structures, TCP, IPC, firewalls, and a packet-stream rate-limiting design problem. Explain design choices and tradeoffs as you work.
Later conversations may involve a manager or engineering leader. One candidate reported a relaxed manager discussion about team dynamics, career goals, and culture, while another reported a director call that shifted immediately into C++ smart-pointer topics.
