Experience: 5 years [India (4), USA (1)]
Education: Masters, Top tier University

Total Interview duration: 2 months (from application to rejection email)

Applied online in the month of September on their careers page. Very time consuming application, asks a lot of questions like Why Palantir? What role and why? (Dev role or Forward Deployed Engineer role?) Why software engineering etc. Pretty much the receival of online assessment depends on the way you fill the application.

Round 1 (1.5hr, Techincal Coding)
Online Assessment, Hackerrank, 3 part question 120 minutes. Each following part depending on the previous part.
Question: Build Dependancy Graph

Approach: Adjacency list -> Topological Sort and Regular expressions for part 3.
Completed OA with in 30 minutes.

Round 2 (1hr) Techincal Coding
Almost after 10 days got email to schedule a Karat interview. Karat is an online platform where they kind of screen candidates before Palantir candidates interview.
2 mins introduction, 15 minutes 3 questions on time & space complexities, followed by 2 Leetcode Medium Graph based questions.

Round 3: (Behavioral)
After a week of Palantir, Technical recruiter (CTR) called for Phone Screening. Almost 45 mins long call. Asked about my background, experience,
why Computer Science? what is so special about it?
why Software engineering? pros and cons of software engineering that you faced in life?
why palantir? what do you know about palantir?
why a specific role? Dev or FDE?
Then told that there would be 2 rounds of interview 1hr each (Learning and Decomposition)

Signed NDA
After 2 weeks got the email for Round 4 and 5. CTR didn't respond for questions like what the interview is going to be like? not much online resources.

Round 4: Decomposition Interview (almost like system design) 1hr
First 20 mins about background, why palantir and behavioral questions.
Then introduced a problem statement and asked ideas to implement a first cut solution.
Then asked to draw various system design components, choice of various options.
Then asked to code apis, optimize api based on data flow.

Round 5: Learning Interview (you have to learn a new concept and start coding) 1hr
First 20 mins, background and behavioral questions.
Next 5 tasks. I was able to reach task 3 then the interview time was exhausted.
Task 1: introduction to problem, it was something like design a custom npm or pip like concept
Task 2: exploring interfaces and objects
Task 3: Implement the concept. (Had to learn and apply a multithreading concept and code it)

I was expecting the next and final round with Manager. But CTR emailed stating they don't have a position that match my skillset. When emailed her about some feedback because of the time and effort I invested for Palantir, no response.

Overall Experience: Very exhausting, Very time consuming, but the Palantir products were great. The interview questions and format was very good.