Thinking about “Cracking Palantir’s Assessment” but not sure what you’re getting into? You’re not alone. Candidates see a mix of classic algorithms, practical debugging, and data-heavy scenarios — and the hardest part is knowing what patterns to master.

If you want to walk into the Palantir Online Assessment (OA) confident, prepared, and ready to perform, this guide is your playbook. No fluff. Real breakdowns. Strategic prep.

When to Expect the OA for Your Role

Palantir doesn’t send the same OA to everyone. The timing and content depend on role, level, and sometimes location.

• New Grad & Intern (SWE/FDE) – Expect an OA invite soon after recruiter contact. It’s often the primary technical screen before on-site/virtual loops.
• Software Engineer (Backend / Full-Stack) – Standard practice. You’ll typically get a HackerRank or CodeSignal link with 2–3 questions under timed conditions.
• Forward Deployed Engineer (FDE) – Often includes algorithms plus a practical coding/debugging or data-transformation twist (think JSON/log parsing).
• Data / Infra / SRE – You may see algorithmic questions plus domain-flavored tasks (log parsing, scheduling DAGs, metrics aggregation).
• Senior Engineering Roles – Some candidates move straight to live coding/design, but many still receive a screening OA.

Action step: When the recruiter reaches out, ask directly: “Which platform, how many questions, and what’s the duration for the OA for this role?” You’ll usually get actionable specifics.

Does Your Online Assessment Matter?

Short answer: yes — and more than you might think.

• It’s the main filter. A standout resume gets you the invite; your OA performance gets you the interview loop.
• It sets the tone. Your OA code can inform later interviews. Expect follow-ups like “Walk me through your solution.”
• It’s realistic. Palantir problems tend to reflect real-world data integration: messy inputs, graphy relationships, correctness under edge cases.
• It signals your engineering style. They’re looking for clarity, test coverage, modularity, and awareness of complexity — not just green checks.

Pro tip: Treat the OA like a first-round interview. Write readable code, add lightweight comments, and explicitly handle edge cases.

Compiled List of Palantir OA Question Types

You won’t get these exact prompts, but these patterns map well to Palantir’s OA. Practice them:

1. Course Schedule — type: Graph / Topological Sort
2. Alien Dictionary — type: Graph / Topological Order from Partial Order
3. Accounts Merge — type: Union-Find / Entity Resolution
4. Number of Islands — type: Graph / BFS-DFS / Connected Components
5. Evaluate Division — type: Graph / Weighted Edges
6. Reorder Data in Log Files — type: Strings / Sorting / Log Parsing
7. Group Anagrams — type: Hashing / Bucketing
8. Meeting Rooms II — type: Intervals / Heap
9. Top K Frequent Elements — type: Heap / Hash Map
10. Word Ladder — type: BFS / Graph
11. K Closest Points to Origin — type: Heap / Geometry
12. LRU Cache — type: Design / Linked Hash Map
13. Flatten Nested List Iterator — type: Iterator / Stack
14. Decode String — type: Stack / String Parsing
15. Subarray Sum Equals K — type: Prefix Sum / Hash Map

How to Prepare and Pass the Palantir Online Assessment

Think of your prep as a sprint to build problem-solving reflexes and practical engineering habits.

1. Assess Your Starting Point (Week 1)

Benchmark yourself across arrays, hashing, graphs, intervals, and strings. Use LeetCode Explore cards or HackerRank practice kits to identify gaps. Track results and label each topic green/yellow/red to focus your plan.

2. Pick a Structured Learning Path (Weeks 2-6)

Choose one:

• Self-study on LeetCode/HackerRank
• Best for disciplined learners. Curate 60–80 problems covering the list above.
• Mock assessments / timed drills
• Use proctored-style sessions to simulate pressure and pacing.
• Career coach or mentor
• A software engineer career coach can review code quality, speed, and communication.

3. Practice With Realistic Problems (Weeks 3-8)

Rotate through graph traversal, union-find, interval scheduling, parsing/normalization, and heap-based aggregation. Time-box each session, then refactor for clarity and add tests for corner cases (empty input, single node, duplicate edges, malformed lines).

4. Learn Palantir-Specific Patterns

Expect scenarios with:

• Entity resolution and deduplication (union-find across overlapping attributes)
• DAGs, job scheduling, and dependency resolution (topological sort with cycles)
• Log/JSON parsing and normalization (robust input handling, partial failures)
• Access control evaluation (role inheritance, permission graphs)
• Streaming or large-scale counters (top-K over sliding windows)
• Schema evolution and backward compatibility checks

5. Simulate the OA Environment

Use the target platform’s IDE (HackerRank/CodeSignal). Turn off all distractions, set a strict timer (commonly 70–90 minutes), and avoid library calls that mask core logic unless permitted. Emulate proctoring: single screen, no copy/paste code snippets, and read input exactly as specified.

6. Get Feedback and Iterate

After each drill:

• Re-run with new test cases you invent (invalid lines, cyclic dependencies, ties).
• Reduce complexity where possible and document assumptions.
• Have a peer or mentor code review for naming, decomposition, and test coverage.

Palantir Interview Question Breakdown

Here are featured sample problems inspired by Palantir-style assessments. Master these patterns and you’ll cover most OA ground.

1. Entity Resolution with Overlapping Attributes

• Type: Union-Find / Hashing
• Prompt: Given user records with partially overlapping emails/phones, merge records that belong to the same person and output canonical profiles.
• Trick: Map each attribute to an ID and union records sharing an attribute. Build components and aggregate fields deterministically.
• What It Tests: Disjoint sets, hashing, memory discipline, and tie-breaking for canonicalization.

2. Build Order from Partial Dependencies

• Type: Graph / Topological Sort
• Prompt: Given tasks and prerequisites, produce a valid execution order. If multiple orders are valid, prefer lexicographically smallest.
• Trick: Kahn’s algorithm with a min-heap for deterministic ordering; detect cycles early.
• What It Tests: Graph modeling, cycle detection, priority queues, and stability in outputs.

3. Log Deduplication Over a Sliding Window

• Type: Sliding Window / Hashing
• Prompt: Stream of log events with timestamps; print an event only if an identical signature hasn’t been printed in the last W seconds.
• Trick: Use a deque or queue for the window plus a hash of signatures to last-seen times; evict stale entries efficiently.
• What It Tests: Streaming patterns, time-window logic, memory vs. accuracy trade-offs.

4. Access Control Evaluation with Role Inheritance

• Type: Graph / DFS-BFS
• Prompt: Given roles, their inheritance DAG, and permissions per role, determine if a user has access to a resource under a policy.
• Trick: Precompute transitive closure or do on-demand traversal with memoization. Watch for cycles and duplicates.
• What It Tests: Graph traversal, caching, idempotency, and careful handling of policy semantics.

5. JSON Flattening and Schema Validation

• Type: Parsing / Recursion
• Prompt: Flatten nested JSON objects/arrays into key paths and validate against a simple schema (required keys, type checks).
• Trick: Recursive DFS carrying a path stack; normalize arrays with indices; handle missing/extra fields gracefully.
• What It Tests: Robust parsing, recursion, input validation, and helpful error reporting.

6. Streaming Top-K Metrics

• Type: Heaps / Hash Map
• Prompt: Maintain the top-K keys by frequency as a stream of events arrives; support updates and queries.
• Trick: Count in a hash map, maintain a min-heap of size K, and update on the fly; consider lazy invalidation for performance.
• What It Tests: Online algorithms, time/space trade-offs, and data structure hygiene.

What Comes After the Online Assessment

Passing the Palantir OA isn’t the finish line — it’s the entry ticket. After you clear it, the process moves from “prove you can code” to “prove you can design, debug, and collaborate.”

Recruiter Debrief & Scheduling

Expect an email within a few days if you pass. You’ll get next-step logistics and a rough outline of the loop. Ask about interview themes (coding, debugging, design, product scenario) so you can target your prep.

Live Coding & Debugging

You’ll pair with one or two engineers in a collaborative editor. Expect:

• Algorithms and data structures similar to the OA, but interactive
• Code reading or debugging in a small codebase with failing tests
• Emphasis on clear communication and incremental fixes

Pro tip: Practice “narrated debugging” — state hypotheses, run focused tests, and summarize findings aloud.

System Design & Data Modeling

Sessions often emphasize:

• Designing pipelines for messy, high-volume data
• Dependency graphs, schedulers, and consistency under failure
• Permissioning and multi-tenant concerns

They’re evaluating decomposition, trade-offs, and clarity — not buzzwords.

Role-Specific Rounds (e.g., FDE)

For Forward Deployed Engineer roles, expect:

• Product-sense questions on scoping and shipping pragmatic solutions
• Data transformation and integration tasks
• Stakeholder trade-offs and communication

Bring concrete examples of balancing speed, correctness, and usability.

Behavioral & Values Alignment

Expect prompts like:

• “Tell me about a time you delivered under ambiguous requirements.”
• “Describe a hard production issue you owned end-to-end.”

Use the STAR method and highlight ownership, pragmatism, and impact.

Final Loop & Offer

The final loop bundles multiple interviews (coding, design, cross-functional). If successful, you’ll get a verbal update followed by a written offer. Compensation often includes base, bonus, and equity — prepare to negotiate with data.

Conclusion

You don’t need to guess — you need a plan. The Palantir OA is tough but predictable. If you:

• Identify weak areas early and address them with targeted reps,
• Drill Palantir-style patterns (graphs, union-find, parsing, intervals, heaps),
• Practice under timed, proctored-like conditions and write clean, tested code,

you’ll turn the OA from a gatekeeper into your invitation to the full interview loop.

Data integration domain knowledge helps, but disciplined problem-solving matters more. Treat the OA like your first interview, and you’ll set yourself up for a stronger run at the offer.

For more practical insights and prep strategies, explore the Lodely Blog or start from Lodely’s homepage to find guides and career resources tailored to software engineers.