Palantir
Big data analytics company for defense, intelligence, and enterprise.
5 Rounds
~28 Days
Very Hard
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Data Engineer
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Behavioral
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medium
Tell me about a time you had to push back on a client or stakeholder's technical request because you knew it wasn't scalable or secure.
#Communication
#Stakeholder Management
#Engineering Standards
Data Engineer
•
Behavioral
•
medium
Palantir works with highly sensitive data. Tell me about a time you had to prioritize security, compliance, or data privacy over delivery speed.
#Security
#Ethics
#Prioritization
Data Engineer
•
Behavioral
•
medium
Describe a situation where you had to work with a highly ambiguous problem statement. How did you define success and execute?
#Ambiguity
#Problem Solving
#Execution
Data Engineer
•
Behavioral
•
medium
Tell me about a time you took ownership of a failing project or pipeline and turned it around.
#Ownership
#Resilience
#Project Management
Data Engineer
•
Behavioral
•
easy
Why Palantir? What specifically about our mission, products (Foundry/Gotham/AIP), or engineering culture makes you want to work here?
#Company Knowledge
#Motivation
#Mission Alignment
Data Engineer
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Behavioral
•
medium
Tell me about a time you disagreed with a senior engineer or architect on a technical decision. How did you handle the disagreement and what was the outcome?
#Conflict Resolution
#Communication
#Teamwork
Data Engineer
•
Behavioral
•
medium
Give an example of a time you optimized a data process or system that saved significant compute resources, time, or money.
#Optimization
#Impact
#Cost Reduction
Data Engineer
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Coding
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medium
Given a list of flight schedules represented as intervals (start_time, end_time), write a function to merge all overlapping flights to determine the total continuous time the airspace is occupied.
#Arrays
#Sorting
#Intervals
Data Engineer
•
Coding
•
medium
Palantir's Foundry maps data into an Ontology. Given a directed graph representing data lineage where nodes are datasets and edges are transformations, write a function to detect if there is a circular dependency.
#Graphs
#DFS
#Cycle Detection
Data Engineer
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Coding
•
medium
Write a SQL query to find the 3-day rolling average of transaction volumes per user, but only include users who have had at least one transaction in the last 30 days.
#SQL
#Window Functions
#CTEs
Data Engineer
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Coding
•
medium
Given a massive log file of user activities, write a program to find the top K most frequent IP addresses. The file is too large to fit into memory.
#Streaming Algorithms
#Heaps
#MapReduce
Data Engineer
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Coding
•
medium
Write a recursive CTE in SQL to traverse an employee-manager hierarchy and return the full management chain for a specific employee.
#SQL
#Recursive CTEs
#Hierarchical Data
Data Engineer
•
Coding
•
hard
Given a string containing a JSON object that might be malformed (missing closing brackets), write a parser that attempts to extract all valid key-value pairs where the key is 'entity_id'.
#String Manipulation
#Parsing
#Regular Expressions
Data Engineer
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Coding
•
medium
Write a SQL query to find users who logged in on 5 consecutive days.
#SQL
#Window Functions
#Gaps and Islands
Data Engineer
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Coding
•
medium
Given a 2D grid representing a map where '1' is land and '0' is water, write a function to find the number of distinct islands. An island is surrounded by water and formed by connecting adjacent lands horizontally or vertically.
#Graphs
#DFS
#BFS
#Matrix
Data Engineer
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Coding
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hard
Write a Python function to deserialize a binary tree from a string representation and then serialize it back to a string.
#Trees
#Serialization
#DFS
#BFS
Data Engineer
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Coding
•
hard
Write a query or script to calculate the median response time from a massive log of API requests. Note that the dataset is too large to sort in memory.
#Statistics
#Distributed Computing
#Approximation Algorithms
Data Engineer
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Coding
•
medium
Design a key-value store with a Time-To-Live (TTL) feature. Once the TTL expires, the key should no longer be accessible and memory should be reclaimed.
#Hash Maps
#Concurrency
#Garbage Collection
Data Engineer
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System Design
•
hard
Design an Entity Resolution system. You are ingesting millions of records from different government databases (e.g., DMV, Tax, Census). How do you design a pipeline to identify and merge records belonging to the same individual?
#Entity Resolution
#Data Pipelines
#Machine Learning
#Graph Processing
Data Engineer
•
System Design
•
hard
Design a data ingestion pipeline for high-frequency IoT sensor data coming from manufacturing plants. The data needs to be available for real-time anomaly detection and also stored for batch historical analysis.
#Streaming
#Lambda/Kappa Architecture
#Kafka
#Data Lake
Data Engineer
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System Design
•
hard
Design a system to track data lineage across thousands of transformations. If a column in a source table is dropped, the system should instantly identify all downstream dashboards and datasets that will break.
#Metadata Management
#Graph Databases
#Data Lineage
Data Engineer
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System Design
•
hard
Design a strict data access control system (Row and Column level security) for a government client where data visibility depends on the user's security clearance and geographic location.
#Security
#Access Control
#Data Governance
Data Engineer
•
System Design
•
hard
Design a distributed task scheduler similar to Apache Airflow or Palantir's Build system. It needs to execute thousands of interdependent data jobs across a cluster of machines.
#Distributed Systems
#Scheduling
#DAGs
Data Engineer
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System Design
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medium
Design a rate limiter for an API that ingests data from external client systems. The system must handle sudden spikes in traffic without dropping critical data.
#Rate Limiting
#API Design
#Distributed Systems
Data Engineer
•
System Design
•
hard
Design an architecture for a real-time anomaly detection system for financial transactions to prevent fraud. The system must evaluate rules against a graph of known bad actors within 50 milliseconds.
#Real-time Processing
#Graph Databases
#Low Latency
Data Engineer
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Technical
•
medium
Write a PySpark script to deduplicate a massive dataset of sensor readings based on a composite key (sensor_id, location_id), keeping only the record with the most recent timestamp.
#PySpark
#Window Functions
#Data Cleaning
Data Engineer
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Technical
•
hard
How do you handle data skew in a distributed join operation in Spark? Walk me through at least three different strategies.
#Spark
#Distributed Computing
#Performance Optimization
Data Engineer
•
Technical
•
medium
Explain the difference between `repartition()` and `coalesce()` in PySpark. In a data pipeline that writes to an S3 data lake, when would you use each?
#PySpark
#Data Partitioning
#Storage Optimization
Data Engineer
•
Technical
•
hard
You are deployed as a Forward Deployed Software Engineer (FDSE) to a client site. Their data is completely undocumented, siloed in legacy databases, and highly messy. What is your step-by-step approach to building a reliable data ontology?
#Data Discovery
#Ontology
#Client Facing
#Data Governance
Data Engineer
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Technical
•
medium
A critical data pipeline in Foundry is failing with an OutOfMemory (OOM) error right before a major client presentation. Walk me through your troubleshooting steps.
#Debugging
#Spark
#Incident Management
Data Engineer
•
Technical
•
hard
Explain how you would implement incremental builds for a massive dataset that receives millions of updates, inserts, and deletes daily. How do you handle late-arriving data?
#Incremental Processing
#Change Data Capture
#Data Lakes
Data Engineer
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Technical
•
medium
What are Broadcast variables and Accumulators in Spark? Provide a real-world data engineering scenario where you would use each.
#Spark
#Distributed Variables
#Optimization
Data Engineer
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Technical
•
hard
How do you handle schema evolution in a long-running data lake environment? What happens if an upstream system changes a column type from INT to STRING?
#Schema Evolution
#Data Governance
#Data Lakes
Data Engineer
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Technical
•
hard
You have a PySpark job that reads from Kafka, joins with a static dimension table, and writes to Cassandra. The job is falling behind the Kafka production rate. How do you optimize it?
#Spark Streaming
#Kafka
#Performance Tuning
Data Engineer
•
Technical
•
medium
How do you design a schema for a highly connected dataset, such as telecom call records, to optimize for graph-like queries (e.g., finding the shortest path of communication between two people)?
#Graph Databases
#Data Modeling
#Query Optimization
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
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Think Out Loud
Always explain your thought process before writing code or drawing architecture.