FDE online assessments and coding screens (Module 6)

By the end of this module you can

Name the first screen each target runs and practice in its format
Map a business-framed problem to its algorithm pattern and state its complexity
Write object-oriented code that absorbs new requirements without a rewrite
Learn a library or concept on the spot and use it under a clock
Trace a bug in unfamiliar code to the line, fix it with a test, then add a feature

Where these rounds are reported

Anthropic publishedAnthropic’s careers page says its technical interviews use live coding tools such as Colab and CodeSignal, where candidates may look things up. Source 1CareersPublisherAnthropicSource typecompany hiring page
Palantir publishedPalantir’s early-talent timeline starts with a HackerRank coding challenge, and Palantir names working inside existing systems and codebases as an interviewed competency. Source 2Students | Palantir Careers (timeline image: RecruitingTimeline_V3.jpg)PublisherPalantirSource typecompany hiring pageSource 3Working Inside Existing SystemsPublisherPalantirSource typecompany hiring page
C3 AI candidate reportsTwo candidates reported, in August 2026, C3 AI FDE processes that opened with an AI-run interview or screening before the coding round. Source 4C3 AI - Forward Deployed Engineer interview process (comment by u/BalanceOdd144)PublisherReddit r/leetcodeSource typecandidate report on RedditSource 5C3 AI Senior Forward Deployed Engineer (FDE) Interview Process – My Experience (comment by u/speedy_string)PublisherReddit r/OfferEngineeringSource typecandidate report on Reddit
Sierra publishedSierra says it is piloting a debugging interview in which candidates improve a colleague’s draft pull request in a medium-sized codebase using coding agents. Source 6The AI-native interviewPublisherSierraSource typecompany blog

No employer publishes a pass rate or a round weight.

The lessons

5 lessons, 1 h 1 min of reading. 5 of 5 live today.

6.1Online assessments and AI-run screens11 minProLive

For each target employer you can name the first screen candidates report (platform, length, format, whether AI is allowed), practice in that format, and handle an AI interviewer or a video screen without losing time.

What it covers

What employers publish about first screens
What candidates report, company by company
AI interviewers and video screens
Mixed assessments: code, SQL, multiple choice and a customer email
Editors without code execution or autocomplete
A practice plan per platform

Key takeaways

Anthropic says its technical roles use live coding tools such as Colab and CodeSignal, Palantir’s early-talent timeline opens with a HackerRank challenge, and Cresta’s posting starts with a self-paced CoderPad assessment.
Candidates reported AI-run screens before any coding at C3 AI, and one Heizen poster reported an AI interview first; one Salesforce commenter reported an assessment that mixed code, SQL, multiple-choice AI questions and a customer email.
One poster preparing for a Google Cloud GenAI FDE coding round quoted a prep document describing a static platform with no code execution, so practice writing code you cannot run.
Do one practice run on the exact platform before the real screen, so the tool never costs you the time.

Practice

3 more planned.

Do this now

Fill in a first-screen card, then solve the longest unique window with nothing that runs, and proofread it

Sign in to read 6.1

6.2Algorithm screens: the problems reported at Google, Palantir and C3 AI13 minProLive

You can map a customer-framed coding problem to its pattern within five minutes, write it in Python without running it, and state its time and space complexity out loud.

What it covers

Who still runs algorithm screens, and who says they don’t
The problems candidates report, company by company
Patterns to have ready: hash maps, sliding windows, stacks, graphs and grids, intervals, expression parsing
Reading a business-framed problem back to its pattern
Writing in a static editor with no code execution
Complexity out loud, space included
A weekly plan by pattern

Key takeaways

Palantir’s guides ask you to turn an algorithm into working code and never forget space complexity, and Ramp says it validates coding, debugging and data structures without over-indexing on perfection.
Candidates report LeetCode-style problems in Google, Palantir and C3 AI loops, and Sierra says it removed algorithm interviews from its engineering process.
A customer framing hides a standard pattern: name the pattern before you write code.
Two candidates tied a rejection to the coding round, one to an error they could not find in time, so treat it as a round you can fail on its own.

Practice

10 more planned.

Do this now

Read install order back to its pattern in five minutes, write it without running it, trace it by hand, say its cost

Sign in to read 6.2

6.3Object-oriented and multi-part problems: build it, extend it, scale it12 minProLive

In a practical round you can write thirty to fifty lines of clean object-oriented Python, absorb two new requirements without a rewrite, and discuss how the design would scale.

What it covers

What candidates report: object-oriented screens, coding plus and three-part problems
Classes and state in a page of code
Leaving room for the next requirement
When a follow-up breaks your design
A flaky API in the middle of the problem
The scale discussion at the end

Key takeaways

Palantir FDSE candidates report object-oriented screens, one of them in Python, and two posters preparing for Google Cloud FDE rounds quoted prep material describing thirty to fifty lines of object-oriented Python.
Palantir’s Writing Good Code page says it will not ask about tricky or obscure language features; our reading is that clean, readable code is the bar.
Design classes so a new requirement arrives as a new field, method or class, not a rewrite.
Notch’s published FDE home assignment puts a create-then-poll API inside the task; put any unreliable API behind one seam from the first class you write.
Silence from hardware is not failure. Treat the state as unknown and take that resource out of use until someone checks.

Practice

8 more planned.

Do this now

Build the inventory model in thirty minutes and absorb two follow-ups without a rewrite

Sign in to read 6.3

6.4Learning rounds: a new library or concept, taught on the spot12 minProLive

Given unfamiliar documentation, or a concept the interviewer explains, you can build a working model of it in five minutes and solve problems of rising difficulty with it.

What it covers

What Palantir publishes about learning and existing systems
What candidates report: package installers, futures, functions from a schema and docs
Reading documentation for the one thing you need
Checking your understanding with a tiny experiment
The question to ask the interviewer
Pacing across problems of rising difficulty

Key takeaways

Palantir’s early-talent timeline lists a learning interview in its virtual onsite, and Palantir names working inside existing systems as an interviewed competency.
Candidate posts and comments about Palantir learning rounds, mostly from interns, new grads or unnamed roles, describe a concept taught on the spot, documentation to learn from, or unfamiliar code to debug or extend; one intern’s account set problems of increasing difficulty.
Read the documentation for the one call you need, then prove your model of it with a tiny experiment before building on it.
Ask the interviewer to confirm your model of the concept early; a wrong model costs every later task.

Practice

4 more planned.

Do this now

Take five minutes for the model and one experiment, then bank each task out loud

Sign in to read 6.4

6.5Re-engineering and debugging rounds: someone else’s code, then a feature13 minProLive

In a codebase you have never seen, you can trace a symptom to the line, fix it with a test, add the requested feature, and narrate your map of the code as you go.

What it covers

What employers publish: Palantir’s competency and Sierra’s pilot round
What candidates report: fix then feature, a giant repo, a short file with one bug
Reading before writing: entry points, data flow, tests
From symptom to hypothesis to line
Debugging against a spec: diagrams, contracts and READMEs
Code review as a round
Using an assistant on unfamiliar code, when it is allowed

Key takeaways

Palantir names working inside existing systems as a competency its interviews are built around, and Sierra, writing about its engineering interviews in general, says it is piloting a debugging interview in which candidates improve a colleague’s draft pull request.
Palantir candidates describe a re-engineering round in someone else’s code, from a bug in a short Java file to one poster’s expectation of a feature on top, and one Scale AI candidate reported debugging a giant repository.
Build a map of the code before changing it, and say it out loud.
Write a failing test before the fix, say how you would repair the damage already done, then add the feature on top.

Practice

11 more planned.

Do this now

Map it aloud, pin the bug with a failing test, fix it, then add a discount without changing any existing call

Sign in to read 6.5

Preview a Pro lesson

Lesson 6.111 minProLive

Online assessments and AI-run screens

For each target employer you can name the first screen candidates report (platform, length, format, whether AI is allowed), practice in that format, and handle an AI interviewer or a video screen without losing time.

What it covers:

What employers publish about first screens
What candidates report, company by company
AI interviewers and video screens
Mixed assessments: code, SQL, multiple choice and a customer email
Editors without code execution or autocomplete
A practice plan per platform

Your first screen may be a timed link, a live editor that cannot run code, or an AI that asks questions before any person does. By the end you can name the screen reported for each target, rehearse in that format, and keep the tool from costing you minutes. What FDE coding rounds test covers the problems; this lesson covers the format.

What employers publish about first screens

You can say which screens an employer publishes, and treat everything else as reported:

Palantir. Its “Students and Early Talent Application Timeline” graphic opens with a HackerRank coding challenge, then a 30-minute chat with a technical recruiter. Source 1Students | Palantir Careers (timeline image: RecruitingTimeline_V3.jpg)PublisherPalantirSource typecompany hiring page Its phone interview page says a phone interview may use HackerRank or Google Docs. Source 2The Phone Interview - Palantir CareersPublisherPalantir TechnologiesSource typecompany hiring page Google Docs runs nothing and completes no code: the static editor described below.
Cresta. As of September 2026, its Senior posting makes a self-paced CoderPad technical assessment the first step after résumé review. Source 3Senior Forward Deployed Engineer (AI Agent)PublisherCresta (Greenhouse job board)Source typecompany job posting
Anthropic. Its careers page says technical roles use live coding tools such as Colab and CodeSignal: “You can look things up—just be comfortable with basic syntax and standard libraries so it doesn’t eat up your time.” Source 4CareersPublisherAnthropicSource typecompany hiring page It names tools, not a stage. Its practical point: know the standard library well enough that a lookup takes seconds.

None of these passages says how a screen is scored, so write for a reader who may see only your code and its test results: clear names, edge cases handled, one line on what you assumed.

Practice

Questions

Design prompts

1 planned

Coding drills

23 planned

SQL drills

1 planned

Locked behind Pro

Every lesson in Module 6 is in Pro, the first lesson included, with its preview and practice.

Get Pro

Onsite this week?

Do these first. Each is live and free.

The evidence behind this module

The plan for this module cites 47 claims: 13 from employers' own pages and postings and 34 candidate reports. How we source what we say.

What Pro adds to this module today

5 of 5 Pro lessons live, and the rest as they ship.
Model answers to 19 questions this module practices Pro

See Pro and pricing

Questions about Module 6

Is Module 6 free?

No. Every lesson in Module 6 is in Pro, the first lesson included.

How long is Module 6?

5 lessons, 61 minutes of reading in all, plus the practice each lesson ends with.

Is Module 6 written yet?

Yes. All 5 lessons are live.

Which kinds of FDE role is it for?

Both: roles at AI labs and AI product companies, and roles at enterprise software and data companies.

Screens and unfamiliar code

By the end of this module you can

Where these rounds are reported

The lessons

What it covers

Key takeaways

Practice

Do this now

What it covers

Key takeaways

Practice

Do this now

What it covers

Key takeaways

Practice

Do this now

What it covers

Key takeaways

Practice

Do this now

What it covers

Key takeaways

Practice

Do this now

Preview a Pro lesson

Online assessments and AI-run screens

What employers publish about first screens

Practice

Questions

Design prompts

Coding drills

SQL drills

Onsite this week?

The evidence behind this module

What Pro adds to this module today

Questions about Module 6

Sources