OpenAI

OpenAI

Leading AI research laboratory developing state-of-the-art foundation models like GPT-4.

5 Rounds ~21 Days Very Hard
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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

DevOps Engineer Behavioral medium

Tell me about a time you had to debug a critical production outage under extreme pressure. What was your process?

#Incident Response #Debugging #Communication
DevOps Engineer Behavioral medium

Describe a situation where you disagreed with a machine learning researcher or software engineer about infrastructure architecture. How did you resolve it?

#Conflict Resolution #Collaboration #Empathy
DevOps Engineer Behavioral easy

Tell me about a time you automated a tedious process that saved your team significant time.

#Automation #Initiative #Impact
DevOps Engineer Behavioral medium

OpenAI moves incredibly fast. Tell me about a time you had to make a trade-off between doing something 'the right way' and doing it quickly to meet a critical business need.

#Trade-offs #Technical Debt #Prioritization
DevOps Engineer Behavioral medium

Tell me about a time you discovered a significant security vulnerability or misconfiguration in your infrastructure. How did you handle it?

#Security #Incident Response #Integrity
DevOps Engineer Coding medium

Write a script to parse a massive, 500GB log file to find the top 10 IP addresses making requests, optimized for memory constraints.

#File I/O #Data Structures #Memory Management #Streaming
DevOps Engineer Coding medium

Implement a token bucket rate limiter in Go or Python that can be used across a distributed system.

#Concurrency #Distributed Systems #Redis
DevOps Engineer Coding medium

Write a function to check if a given CIDR block overlaps with a list of existing CIDR blocks in a VPC.

#Networking #Bit Manipulation #IP Addressing
DevOps Engineer Coding medium

Given a list of server dependencies (e.g., A depends on B, B depends on C), write a script to determine the correct startup order.

#Graphs #Topological Sort #DFS/BFS
DevOps Engineer Coding hard

Write a concurrent Go program (or Python with asyncio) to ping 10,000 endpoints and return a list of unreachable ones within a strict 5-second timeout.

#Concurrency #Networking #Goroutines #Asyncio
DevOps Engineer Coding medium

Implement a basic load balancer in Python that distributes incoming requests to a list of backend servers using a weighted round-robin algorithm.

#Load Balancing #Math #Data Structures
DevOps Engineer System Design hard

Design a distributed checkpointing system for large-scale model training that needs to write terabytes of state data every 10 minutes without blocking GPU execution.

#Distributed Systems #Storage #High Throughput #GPU Infrastructure
DevOps Engineer System Design hard

Design a high-throughput, low-latency API gateway for LLM inference that handles streaming responses (e.g., Server-Sent Events).

#API Gateway #Load Balancing #Streaming #WebSockets/SSE
DevOps Engineer System Design medium

Design a CI/CD pipeline for deploying a microservice that serves a new machine learning model to millions of users, ensuring zero downtime.

#Deployment Strategies #Canary Releases #Rollbacks #Testing
DevOps Engineer System Design hard

Design an auto-scaling system for inference nodes based on custom metrics like queue depth and GPU memory fragmentation, rather than just CPU usage.

#Auto-scaling #Custom Metrics #KEDA #Capacity Planning
DevOps Engineer System Design medium

Design a highly available internal DNS architecture for a multi-region cloud environment that supports millions of internal queries per second.

#DNS #Networking #High Availability
DevOps Engineer System Design hard

Design a centralized logging architecture capable of ingesting petabytes of logs per day from distributed inference servers with sub-minute search latency.

#Logging #Big Data #Elasticsearch #Kafka
DevOps Engineer System Design hard

Design a system to securely distribute multi-gigabyte model weights to thousands of edge inference nodes globally with minimal latency and network cost.

#Content Delivery #Peer-to-Peer #Security #Edge Computing
DevOps Engineer Technical hard

How do you handle Kubernetes node failures in a cluster running long-lived, stateful GPU training jobs?

#Kubernetes #Fault Tolerance #StatefulSets #GPU Scheduling
DevOps Engineer Technical medium

Explain how you would optimize Docker image builds for a massive Python monorepo to reduce CI times from 45 minutes to under 10 minutes.

#Docker #CI/CD #Caching #Monorepo
DevOps Engineer Technical medium

How does Terraform handle state lock, and what exactly happens if the state file gets corrupted during a massive infrastructure rollout?

#Terraform #State Management #Disaster Recovery
DevOps Engineer Technical hard

Describe how you would monitor and alert on GPU utilization, memory bottlenecks, and interconnect health across a 10,000-node cluster.

#Prometheus #DCGM #GPU Monitoring #Alerting
DevOps Engineer Technical hard

What is InfiniBand, and how does RDMA differ from traditional TCP/IP networking in the context of distributed model training?

#InfiniBand #RDMA #TCP/IP #High Performance Computing
DevOps Engineer Technical medium

How do you manage and rotate secrets in a multi-tenant Kubernetes environment at scale without restarting pods?

#Kubernetes #Secret Management #Vault #Security
DevOps Engineer Technical easy

Explain the difference between Kubernetes Deployments, StatefulSets, and DaemonSets. When would you use each for AI workloads?

#Kubernetes Resources #Workload Management
DevOps Engineer Technical medium

How do you troubleshoot a 'CrashLoopBackOff' error in Kubernetes, specifically if the pod contains a GPU-bound container that fails silently?

#Debugging #Containers #GPU
DevOps Engineer Technical hard

What are the challenges of using Terraform with hundreds of developers, and how do you structure the repositories and state files to prevent bottlenecks?

#Terraform #Scaling Teams #Architecture
DevOps Engineer Technical medium

How do you handle database schema migrations in a zero-downtime CI/CD pipeline?

#CI/CD #Database Migrations #Zero Downtime
DevOps Engineer Technical hard

Explain how Prometheus handles high cardinality data and how you would mitigate a cardinality explosion caused by a misconfigured label.

#Prometheus #TSDB #Monitoring
DevOps Engineer Technical medium

Walk me through the exact lifecycle of a Kubernetes pod from the moment `kubectl apply` is executed to when the container is running.

#Kubernetes Architecture #API Server #Kubelet #Scheduler
DevOps Engineer Technical hard

How do you secure a multi-tenant Kubernetes cluster where different research teams need strict compute and network isolation?

#Kubernetes Security #Network Policies #RBAC #Multi-tenancy
DevOps Engineer Technical hard

What is eBPF, and how can it be used for network observability and security in a high-throughput microservices architecture?

#eBPF #Linux Kernel #Observability #Cilium
DevOps Engineer Technical medium

How do you implement blue-green deployments for a stateful application backed by a relational database?

#Deployment Strategies #Databases #Stateful Applications
DevOps Engineer Technical medium

Explain the role of a Service Mesh (like Istio or Linkerd). What specific problems does it solve, and what overhead does it introduce?

#Service Mesh #Microservices #mTLS #Traffic Management
DevOps Engineer Technical hard

How would you design a disaster recovery plan for a cloud-native LLM application relying heavily on managed cloud services (e.g., Azure Cosmos DB, Blob Storage)?

#Disaster Recovery #Azure #RTO/RPO #High Availability

Difficulty Radar

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Senior Engineer

Focuses 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.

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