Palantir Staff Software Engineer Interview Questions

1.Tell me about a time you inherited a project with no clear requirements or scope. How did you figure out what to actually build, and what did you ship?

2.Tell me about a time you shipped something meaningful in a domain you had almost no background in — where did you start, and what did deep enough look like?

3.Walk me through the most severe production incident you've owned — one where systems were down and there was real organizational pressure on you. What did you do, and what broke down?

4.Tell me about a time you had to explain a deeply technical architecture decision to a senior executive or non-technical customer who had real decision-making power over it. How did you prepare and how did it land?

5.Describe a time when you were asked to scope and lead a project where the problem statement itself was wrong. How did you figure that out, and what did you do about it?

6.Tell me about a time you had to make an irreversible technical decision under a hard deadline with incomplete information. What was the call, and would you make it again?

7.You're designing a new Conjure API endpoint for Foundry that needs to handle both internal platform traffic and external customer-facing requests. What's your process for versioning and evolving that API without breaking existing clients?

8.A Spark job processing Parquet datasets in Foundry is completing successfully but producing silently incorrect output — no errors, no missing rows, just wrong values in roughly 3% of records. How do you track this down?

9.We're building a multi-tenant data access layer in Foundry where different enterprise customers must be strictly isolated — same physical infrastructure, but a customer in healthcare must never see data belonging to a defense contractor. Walk me through how you'd architect the authorization layer.

10.You're a staff engineer on AIP and you need to add streaming LLM response support — server-sent events from the model to the browser — through an existing GraphQL API layer. What changes at each layer of the stack, and where are the hard problems?

11.Apollo ships Palantir software to thousands of environments, including air-gapped government networks. You need to redesign the rollout strategy so a bad deploy to a classified environment can be automatically detected and rolled back without any human in the loop — because there may be no human available at 3am in that environment. How do you approach this?

12.You're a staff engineer on Gotham's backend, and an intelligence analyst reports that a query joining three large entity datasets — persons, locations, and events — returns results in 400ms in the test environment but takes over 45 seconds in production. Both environments run the same code. What's your investigation plan?

13.Foundry's ontology syncs object types and links across dozens of customer deployments. How would you design the sync protocol so that a schema change — say, adding a required property to an object type — doesn't silently break downstream pipelines that consume that type?

14.AIP lets enterprise customers run LLM-powered agents against their operational Foundry data. How would you design an audit log system that captures every data access an agent makes — granular enough that a compliance officer can reconstruct exactly what the model saw and why?

15.Gotham is used by intelligence analysts who need to search across billions of entity records in near real-time. Design an incremental indexing pipeline that keeps the search index fresh within 60 seconds of a new entity being ingested — without full re-indexes and without downtime.

16.Apollo needs to orchestrate software releases across thousands of customer environments with wildly different constraints — some on AWS, some on-prem, some in air-gapped networks that phone home only intermittently. Design the scheduling and state-tracking layer that decides what to deploy where and when, given that Apollo itself may not have a live connection to every environment.

17.Foundry's pipeline execution engine needs to support thousands of concurrent data transforms — some running for seconds, some for hours — across a shared Spark cluster, with fair resource allocation across tenants and priority lanes for time-sensitive operational workflows. How would you design the scheduler?

18.AIP agents in production are making tool calls that retrieve live Foundry data. You need to design a rate-limiting and quota enforcement layer that prevents a single runaway agent session from exhausting the data platform — while keeping the latency overhead under 5ms per tool call, and enforcing limits that operators can adjust in real time without a deploy.

19.Tell me about a time you had to convince a skeptical peer or senior engineer to adopt a technical standard or practice you championed. What resistance did you face and how did you move them?

20.Describe a time you spotted a serious technical risk in a project you weren't leading — something the team owning it hadn't seen. How did you raise it and what happened?

21.Tell me about a time you had to fundamentally change how a team approached a problem mid-project — not just adjust tactics, but reset the direction entirely. What forced your hand and how did you manage the transition?

22.You're the most senior engineer on a project and you realize the timeline your team committed to a major government customer is not achievable — the work is about twice as large as scoped. What do you do, and how do you tell the customer?

23.Tell me about a time you had to decide whether to build something in-house versus adopting an external solution — for a component that would be deeply load-bearing in production. How did you make the call, and would you make it the same way today?

24.Tell me about a time you had to make a high-stakes technical decision that required you to take a position on an ethical or policy dimension — not just an engineering one. How did you think it through and who did you involve?

25.Estimate how many Foundry pipeline runs Palantir processes globally in a single day. Walk me through your reasoning.

26.A government customer on Gotham reports that analyst satisfaction scores dropped sharply over the past quarter, but nothing in the system metrics looks wrong — latency is fine, error rates are flat. Where do you start?

27.Palantir's AIP platform charges enterprise customers partly based on compute consumed by LLM agent workflows. How would you instrument and estimate the cost attribution of a multi-step agent session that fans out across several Foundry datasets and makes a dozen tool calls?

28.Estimate the storage cost to Palantir of retaining full audit logs for every AIP agent data access across all enterprise customers for seven years, as might be required by regulated industries. What drives the number and what would you do to bring it down?

29.Palantir is considering offering Foundry as a fully self-hosted, customer-managed deployment — no Palantir SREs, no Apollo connection, customer runs it all. Walk me through the product, engineering, and business risks of that model and how you'd think about whether to build it.

30.Palantir's AIP platform gives enterprise operators the ability to configure which LLM tools and Foundry datasets an agent can access. Estimate the blast radius if a misconfigured operator policy accidentally grants a high-privilege agent access to a dataset it shouldn't touch — and design the guardrail layer that catches it before it causes harm.