Do FDE interviews have LeetCode? What employers publish and candidates report, company by company

By FDE Interview Prep, a SourceStrongAI company

In this post11 sections

1. The short answer
2. What employers publish about coding rounds
3. What candidates report, company by company
4. Is the FDE coding bar lower than the software engineering bar?
5. Where the algorithms round has been replaced
6. What practical coding looks like
7. How to split your prep time by target
8. A practice plan for both kinds of round
9. Questions people ask
10. Keep reading
11. More from the blog

You have a few weeks before the loop and two ways to spend your evenings: grind algorithm problems, or build something that looks like the job. Pick wrong and you walk into a hash-map question with a polished demo and no speed, or into a long build with nothing but memorized patterns. The short answer: some FDE loops have LeetCode-medium rounds, some have replaced them with builds, and the employer, not the title, decides; here is the evidence, company by company. For the whole loop, round by round, read the FDE interview guide.

The short answer

Candidates report LeetCode-medium coding rounds for FDE roles at Google and C3 AI. ^{[1, 2, 3, 4, 5]}Source 1Google FDE - Forwarde Deployed Engineer Interview (post by u/Awkward-Money-9912)PublisherReddit r/leetcodeSource typecandidate report on RedditSource 2Google FDE - Forwarde Deployed Engineer Interview (comment by u/Awkward-Money-9912)PublisherReddit r/leetcodeSource typecandidate report on RedditSource 3C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (post by u/Wrong_Classic_7306)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 4C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/Wrong_Classic_7306)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 5C3 AI - Forward Deployed Engineer interview process (comment by u/BalanceOdd144)PublisherReddit r/leetcodeSource typecandidate report on Reddit Leo Mehr, Ramp’s Director of Engineering, said in June 2026 that Ramp’s FDE candidates must pass the software engineering interview loop. ^[6]Source 6What is a Forward Deployed Engineer? (FDE Explained) feat. Leo Mehr of Ramp (YouTube auto-generated English captions)PublisherdearCC (Clara Shih), YouTubeSource typerecorded talk or interview At the other end, Sierra says it removed coding and algorithms interviews from its engineering process and replaced them with an AI-native onsite. ^[7]Source 7The AI-native interviewPublisherSierraSource typecompany blog

So “FDE” does not tell you the format. The employer does.

Three rules hold across every target:

• Fundamentals are never wasted. In our reading, even the practical formats below end in working code on a clock.
• The frame can change more than the core. One Google candidate described a LeetCode-medium problem presented as a real-world scenario rather than a traditional algorithm question. ^{[8, 9, 10]}Source 8FDE Interview Experience at Google (L4) (Blind)PublisherBlindSource typecandidate report on BlindSource 9Is Google FDE interview same as SWE? (Blind)PublisherBlindSource typecandidate report on BlindSource 10Google Forward Deployed Engineer Interview Experience (Blind)PublisherBlindSource typecandidate report on Blind
• Ask. The recruiter can tell you the format before the day; the questions to send are at the end of this post.

What employers publish about coding rounds

Employers rarely describe an FDE-only round, but they say what they value in code.

Palantir publishes coding guides for its interviews. One says a core facet of a good coding interview is translating a conceptual algorithmic solution into working code, and tells candidates to think about edge cases and how their code could break. ^[11]Source 11Writing Good CodePublisherPalantirSource typecompany hiring page Another tells candidates to know how to calculate the efficiency of algorithms and not to forget space complexity. ^[12]Source 12Analyzing the Efficiency of CodePublisherPalantirSource typecompany hiring page

Ramp’s engineering blog says its FDE hiring validates coding, debugging, data structures and system design as a bar to pass, without over-indexing on “perfection”. ^[13]Source 13Forward Deployed EngineeringPublisherRamp Builders (engineering blog)Source typecompany blog

OpenAI’s interview guide says that in engineering interviews it generally looks for well-designed solutions, high-quality code, optimal performance and good test coverage. ^[14]Source 14OpenAI interview guide (archived)PublisherOpenAISource typearchived company page It also says expectations for AI tools vary by interview, and that the preparation materials explain what is allowed. ^[15]Source 15Interview Guide | OpenAIPublisherOpenAISource typecompany hiring page

Together: correct code from an idea, its cost stated, edge cases handled, tests written. An algorithm round rewards that too; only the wrapper differs.

What candidates report, company by company

Here is the evidence in one table, with who is speaking and when. A report is one person’s account of one loop, not the company’s policy.

What the table leaves out:

• Google. The two L4 posts on Blind from July 2026 may come from the same person, so we count them as one account. ^{[8, 9, 10, 30]}Source 8FDE Interview Experience at Google (L4) (Blind)PublisherBlindSource typecandidate report on BlindSource 9Is Google FDE interview same as SWE? (Blind)PublisherBlindSource typecandidate report on BlindSource 10Google Forward Deployed Engineer Interview Experience (Blind)PublisherBlindSource typecandidate report on BlindSource 30Google FDE AdvicePublisherBlind (teamblind.com)Source typecandidate report on Blind In one, a poster who got an L4 offer described the single coding question as “almost leetcode easy/medium”, next to a conversation about building an agentic system. ^[30]Source 30Google FDE AdvicePublisherBlind (teamblind.com)Source typecandidate report on Blind
• C3 AI. The LeetCode sits in the coding round, not the AI screen before it: in a Reddit thread about C3 AI’s FDE process, one commenter said the AI interview had no LeetCode. ^[31]Source 31C3 AI - Forward Deployed Engineer interview process (comment by u/FickleLingonberry873)PublisherReddit r/leetcodeSource typecandidate report on Reddit One commenter in a Senior FDE thread, who did not name the company, described, in September 2026, a coding round with “very vague requirements” where they had to ask questions as an FDE would with a client. ^{[32, 33]}Source 32C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/becquerwrecker)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 33C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/becquerwrecker)PublisherReddit r/OfferEngineeringSource typecandidate report on Reddit
• Palantir. Two candidates described two different formats, months apart. ^{[19, 20]}Source 19Palantir Interview Process... So Far, FDSE 2024 (post by u/kircher32245)PublisherReddit r/csMajorsSource typecandidate report on RedditSource 20Palantir Forward Deployed Engineer Interview ExperiencePublisherAced (formerly Exponent)Source typecandidate’s personal write-up That is why you ask.

To build this table for your own targets, the free lesson The evidence map walks through the method.

Which problems candidates report

Where a report names the problem, here is what it was:

• Hash map: one candidate for C3 AI and one for Palantir FDSE reported it, in August 2026 and November 2024. ^{[3, 4, 19]}Source 3C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (post by u/Wrong_Classic_7306)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 4C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/Wrong_Classic_7306)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 19Palantir Interview Process... So Far, FDSE 2024 (post by u/kircher32245)PublisherReddit r/csMajorsSource typecandidate report on Reddit
• Sliding window with a hash map: one candidate for C3 AI reported it, in August 2026. ^[5]Source 5C3 AI - Forward Deployed Engineer interview process (comment by u/BalanceOdd144)PublisherReddit r/leetcodeSource typecandidate report on Reddit
• Stack-based sliding window: one candidate for C3 AI reported it, in August 2026. ^[16]Source 16C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/speedy_string)PublisherReddit r/OfferEngineeringSource typecandidate report on Reddit
• Array shifting: one commenter in a Palantir FDSE thread described the game 2048, in January 2025, without naming the employer. ^[34]Source 34Palantir Interview Process... So Far, FDSE 2024 (comment by u/shochmut)PublisherReddit r/csMajorsSource typecandidate report on Reddit
• Identifier conversion: one poster on Blind posted it secondhand from a Google Senior FDE phone screen, in July 2026. ^{[8, 9, 10]}Source 8FDE Interview Experience at Google (L4) (Blind)PublisherBlindSource typecandidate report on BlindSource 9Is Google FDE interview same as SWE? (Blind)PublisherBlindSource typecandidate report on BlindSource 10Google Forward Deployed Engineer Interview Experience (Blind)PublisherBlindSource typecandidate report on Blind

Is the FDE coding bar lower than the software engineering bar?

Not at every company. Ramp’s Director of Engineering said FDE candidates pass the software engineering loop, and a former Palantir recruiter told First Round Review, in February 2026, that Palantir’s early FDEs passed the same interview loops as software engineers. ^{[6, 35]}Source 6What is a Forward Deployed Engineer? (FDE Explained) feat. Leo Mehr of Ramp (YouTube auto-generated English captions)PublisherdearCC (Clara Shih), YouTubeSource typerecorded talk or interviewSource 35So You Want to Hire a Forward Deployed EngineerPublisherFirst Round ReviewSource typenews report Nabeel Qureshi, who spent nearly eight years as a Palantir FDE, said on Lenny’s Podcast, YouTube edition, in May 2025, that Palantir also had a second FDE type, whose technical interview was more about reasoning with data. ^[36]Source 36How Palantir built the ultimate founder factory | Nabeel S. Qureshi (YouTube uploaded en-US captions)PublisherLenny's Podcast, YouTubeSource typerecorded talk or interview If you are weighing whether the role is a lesser engineering job, read whether FDE is a step down from software engineering.

Where the algorithms round has been replaced

Sierra is the clearest public case. In an April 2026 blog post it says it removed coding and algorithms interviews from its engineering process and replaced them with an AI-native onsite in three parts: Plan, Build and Review. ^[7]Source 7The AI-native interviewPublisherSierraSource typecompany blog In Plan, the candidate drives the idea for a product while interviewers ask questions; in Review, the candidate demos what they built and the product choices are debated. ^[7]Source 7The AI-native interviewPublisherSierraSource typecompany blog The Build part runs for 2 hours, with the AI tooling of the candidate’s choice. ^[7]Source 7The AI-native interviewPublisherSierraSource typecompany blog The post covers Sierra’s engineering interviews in general, not an FDE-only loop. As of September 2026, Sierra’s customer-facing role for building agents is titled “Software Engineer, Agent”, not FDE. ^[37]Source 37Software Engineer, AgentPublisherSierra (Ashby)Source typecompany job posting

The other signals are softer: posters on Blind wrote, before their rounds, that a recruiter or the invitation, at Cohere, Scale AI and OpenAI, called the round practical or not LeetCode. ^{[22, 27, 28, 29]}Source 22OpenAI Forward Deployed SWE RolePublisherBlind (teamblind.com)Source typecandidate report on BlindSource 27Cohere coding interview (Blind)PublisherBlindSource typecandidate report on BlindSource 28Cohere FDE onsite, AI enabled coding round? (Blind)PublisherBlindSource typecandidate report on BlindSource 29Scale AI InterviewPublisherBlindSource typecandidate report on Blind Treat those as a reason to prepare practical coding, not as proof that no algorithm will appear.

What practical coding looks like

“Practical” is not easier. It moves the difficulty from spotting the pattern to shipping working code on messy input, with the interviewer changing the requirements.

Compare two problems with the same core. First, the algorithm version: find the longest stretch of a log where no reading repeats.

def longest_unique(xs):
    last, lo = {}, 0
    best = (0, 0)  # (length, start)
    for hi, x in enumerate(xs):
        if last.get(x, -1) >= lo:
            lo = last[x] + 1
        last[x] = hi
        if hi - lo + 1 > best[0]:
            best = (hi - lo + 1, lo)
    return best

The guard last.get(x, -1) >= lo is the whole problem: without it, an old position drags the window backwards. Small bugs matter: one candidate for a C3 AI FDE role wrote on Reddit, in August 2026, that an indentation error they could not find in time ended their process. ^[5]Source 5C3 AI - Forward Deployed Engineer interview process (comment by u/BalanceOdd144)PublisherReddit r/leetcodeSource typecandidate report on Reddit

Now a practical version: parse web server logs and report the slowest endpoints by p95 latency. Each line is a method, a path and a latency in milliseconds, and some lines are junk:

GET /orders 182.5
GET /orders 40
GET /search 950
garbage

import math
from collections import defaultdict

def p95(v):
    v = sorted(v)
    i = (95 * len(v) + 99) // 100 - 1  # nearest rank
    return v[i]

def slowest(lines, k=3):
    ms, bad = defaultdict(list), []
    for n, line in enumerate(lines, 1):
        try:
            _, path, t = line.split()
            t = float(t)
            if not math.isfinite(t):
                raise ValueError
        except ValueError:
            bad.append(n)
            continue
        ms[path].append(t)
    score = {p: p95(ms[p]) for p in ms}
    top = sorted(score, key=score.get,
                 reverse=True)[:k]
    return top, score, bad

On the four sample lines, slowest ranks /search above /orders and returns bad = [4].

Note the order inside the loop: parse first, then touch the dictionary, or a bad line leaves an empty list and p95 crashes. What gets judged is the rest, in our reading: bad lines are kept by line number, not silently dropped; the percentile method is named (nearest rank); and when the interviewer says “now it’s a month of logs and they don’t fit in memory”, you have an answer ready about streaming and approximate percentiles.

Practice both shapes with our free questions: the sliding-window rate limiter, which turns the window into a production component, the p95 log parser, and refactoring a long function to be testable, which is the “someone else’s code” format.

What to say in each kind of round

The words differ more than the code. In an algorithm round framed as a customer story:

• “Let me restate it as input and output: a list of readings in, the length and start of the longest clean stretch out.”
• “The brute force checks every start, which is quadratic. I’ll keep a window and a map of last positions instead: linear time, and space for the distinct readings.”
• “Edge cases before I code: an empty log, every reading the same, and a repeat that sits before the window.”

In a practical round:

• “I’ll get one working path end to end first, then handle the bad input, then speed.”
• “Here’s what I’m doing with lines that don’t parse: I’m keeping their line numbers so the customer can see them.”
• “If this has to run on the full day of logs, here is what changes.”

The Aced poster who described Palantir’s round as practical gave one piece of advice: prioritize a working solution over unfinished, optimized code. ^[20]Source 20Palantir Forward Deployed Engineer Interview ExperiencePublisherAced (formerly Exponent)Source typecandidate’s personal write-up That is one candidate’s view, and also how we coach practical rounds.

Common mistakes, and the fix

• Treating the story as decoration. The scenario hides the edge cases. Fix: ask what one bad record looks like before you code.
• Going silent while you optimize. Fix: say the brute force and its cost out loud, then improve it.
• Only practicing on a blank file. Some rounds hand you code you did not write: one Palantir FDSE candidate wrote, in November 2024, that the onsite would include a “reengineering” round in an unfamiliar codebase, and one Blind poster wrote, in September 2026, that a friend’s Cohere recruiter described an existing Python codebase. ^{[19, 27, 28]}Source 19Palantir Interview Process... So Far, FDSE 2024 (post by u/kircher32245)PublisherReddit r/csMajorsSource typecandidate report on RedditSource 27Cohere coding interview (Blind)PublisherBlindSource typecandidate report on BlindSource 28Cohere FDE onsite, AI enabled coding round? (Blind)PublisherBlindSource typecandidate report on Blind Fix: do one refactor or bug hunt each week.
• Skipping tests in a practical round. Fix: write two asserts before you call it done, one normal and one broken input.

How to split your prep time by target

What follows is our advice, not anything an employer publishes. We have found no employer that publishes a pass rate or how it weights rounds, and we publish none; the post on what no one publishes about FDE interviews traces the figures that circulate.

Sort each company on your list into one of three groups, using the table above and your recruiter’s answers:

• Algorithm reported. Reports describe LeetCode-style problems, or the employer says FDEs pass the software engineering loop: Google, C3 AI, Microsoft and Ramp in the table above. Weight toward the problems candidates report, hash maps, sliding windows and stacks, plus sorting, our own addition, since the p95 parser above depends on it. Frame each as a customer story.
• Practical or AI-native. The employer publishes a build-based format, or a poster was told the round is practical: Sierra, Cohere and Scale AI above. Weight toward staged builds, messy data and working inside existing code, with and without an assistant.
• Mixed or unknown. Reports disagree, as they do for Palantir, OpenAI and Anthropic, or there are none. Pair one algorithm problem with one practical build in every session, and ask the recruiter.

Then pick the week that matches your list. Two examples:

Mostly algorithm targets
Mon  2 timed problems, cost aloud
Tue  2 timed problems + 1 story frame
Wed  p95 log parser, 45 min
Thu  2 timed problems, no running code
Fri  mock round, then review

Mostly practical targets
Mon  staged build, then extend it
Tue  refactor someone else's code
Wed  1 timed algorithm problem
Thu  build with an AI assistant,
     explain every kept line
Fri  mock round, then review

If your list mixes both groups, alternate the two weeks, and keep an algorithm problem in every practical week, because the screen can be an algorithm problem even when later rounds are not: one Palantir FDSE candidate wrote on Reddit, in November 2024, that their screen was a LeetCode-medium problem on HackerRank CodePair, and that the onsite would add decomposition and a “reengineering” round in an unfamiliar codebase. ^[19]Source 19Palantir Interview Process... So Far, FDSE 2024 (post by u/kircher32245)PublisherReddit r/csMajorsSource typecandidate report on Reddit The post on FDE online assessments covers HackerRank, CodeSignal and AI-run screens.

A practice plan for both kinds of round

First, send the recruiter these questions in writing. Even “we can’t say” tells you something.

Don’t skip the last question. OpenAI’s guide says some interview formats allow AI tools and others are designed to assess problem-solving without them. ^[15]Source 15Interview Guide | OpenAIPublisherOpenAISource typecompany hiring page Sierra’s Build part uses the AI tooling of the candidate’s choice. ^[7]Source 7The AI-native interviewPublisherSierraSource typecompany blog

Then drill in this order:

1. Know which side is weaker. The free lesson What FDE coding rounds test, by the evidence sorts rounds into four kinds and gives a one-line verdict template for each target. The double bar shows how to find whether coding or customer work is your weaker side.
2. Do one algorithm problem framed as a customer story. Say the brute force, the better approach, and the cost. The question on time and space complexity in production makes you say when the cost matters.
3. List edge cases before you type. The question on edge cases before you code drills the habit.
4. Do one practical build and one refactor. Start with the p95 log parser and the testable refactor.
5. Run a mock with a timer and a listener. Narrate as you go. A silent candidate gives the interviewer nothing to judge, whichever format it is.

The FDE coding round is not one thing, and nothing in the evidence says you can skip either half. Keep the fundamentals sharp for every target, then shift your weekly hours toward the format your list points to. Open the free p95 log parser, set a timer, and write it before you read the model answer; then do the sliding-window rate limiter the same way. The coding questions below cover both kinds of round.

Questions people ask

Do FDE interviews have LeetCode questions, and what do candidates report?

Some do. Candidates report LeetCode-medium coding rounds for FDE roles at Google and C3 AI, while Sierra says it removed coding and algorithms interviews from its engineering process. Check what each employer publishes and prepare for both kinds of round.^{[1, 2, 3, 4, 5, 7]}Source 1Google FDE - Forwarde Deployed Engineer Interview (post by u/Awkward-Money-9912)PublisherReddit r/leetcodeSource typecandidate report on RedditSource 2Google FDE - Forwarde Deployed Engineer Interview (comment by u/Awkward-Money-9912)PublisherReddit r/leetcodeSource typecandidate report on RedditSource 3C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (post by u/Wrong_Classic_7306)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 4C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/Wrong_Classic_7306)PublisherReddit r/OfferEngineeringSource typecandidate report on RedditSource 5C3 AI - Forward Deployed Engineer interview process (comment by u/BalanceOdd144)PublisherReddit r/leetcodeSource typecandidate report on RedditSource 7The AI-native interviewPublisherSierraSource typecompany blog

Is the FDE coding bar lower than the software engineering bar?

Not at every company. Ramp’s Director of Engineering said FDE candidates must pass the same software engineering interview loop, and Ramp’s engineering blog says its FDE hiring validates coding, debugging, data structures and system design as a bar to pass.^{[6, 13]}Source 6What is a Forward Deployed Engineer? (FDE Explained) feat. Leo Mehr of Ramp (YouTube auto-generated English captions)PublisherdearCC (Clara Shih), YouTubeSource typerecorded talk or interviewSource 13Forward Deployed EngineeringPublisherRamp Builders (engineering blog)Source typecompany blog

What does practical coding mean in an FDE interview?

Problems that look like the job, such as parsing messy logs, cleaning data, calling an API, extending a feature, or reading and fixing code you did not write. In our reading, a practical round judges working code, sensible handling of bad input and tests more than spotting a known pattern.

How do I find out which kind of coding round I will get?

Ask the recruiter what the round looks like, which language and environment it uses, and whether AI tools are allowed. OpenAI’s interview guide, for example, says expectations for AI tools vary by interview and are explained in the preparation materials.^[15]Source 15Interview Guide | OpenAIPublisherOpenAISource typecompany hiring page

Keep reading

Guides

• The forward deployed engineer interview, round by round

Lessons

• What FDE coding rounds test, by the evidence
• The evidence map: what employers publish, what candidates report, how to read both
• The double bar: technical enough, and trusted in front of a customer

Questions

• Implement a sliding-window rate limiter and explain its memory cost.
• Parse web server logs and report the slowest endpoints by p95 latency.
• Here is a long function that reads files, calls an API and writes a report. Refactor it so you can test it.
• State the time and space complexity of your solution and say when it would matter in production.
• Before you write code for this parser, list the inputs that will break it.

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