OpenAI
Leading AI research laboratory developing state-of-the-art foundation models like GPT-4.
5 Rounds
~21 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
Cloud Engineer
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Behavioral
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medium
Tell me about a time you had to make a significant infrastructure architecture decision with incomplete information under extreme time pressure.
#Decision Making
#Ambiguity
#Pressure
Cloud Engineer
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Behavioral
•
medium
Describe a time you caused a major production outage. How did you handle the immediate mitigation, and what systemic changes did you implement during the post-mortem?
#Post-mortem
#Accountability
#SRE Practices
Cloud Engineer
•
Behavioral
•
medium
OpenAI moves at an incredibly fast pace, and priorities can shift overnight. Give an example of how you managed a sudden pivot in a major infrastructure project you were leading.
#Agility
#Project Management
#Communication
Cloud Engineer
•
Behavioral
•
medium
Tell me about a time you caused a significant production outage. What happened, how did you fix it, and what did you learn?
#Incident Management
#Accountability
#Post-mortems
Cloud Engineer
•
Behavioral
•
medium
Tell me about a time you had to push back on a feature request from a researcher or senior engineer because it was architecturally unsound.
#Conflict Resolution
#Stakeholder Management
Cloud Engineer
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Behavioral
•
medium
Tell me about a time you optimized cloud infrastructure costs significantly without degrading system performance.
#FinOps
#Optimization
#Impact
Cloud Engineer
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Behavioral
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easy
Describe a time you had to learn a deeply technical and complex concept very quickly to solve a critical issue.
#Adaptability
#Learning
#Problem Solving
Cloud Engineer
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Behavioral
•
medium
Tell me about a time a critical deployment failed during a major product launch. How did you handle the situation and the stakeholders?
#Crisis Management
#Communication
#Resilience
Cloud Engineer
•
Behavioral
•
medium
How do you prioritize addressing engineering debt versus shipping new infrastructure features required by the research teams?
#Prioritization
#Engineering Excellence
#Trade-offs
Cloud Engineer
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Coding
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medium
Write a Python script that interacts with the Kubernetes API to find all pods stuck in a 'CrashLoopBackOff' state across all namespaces, logs their last termination reason, and restarts their respective deployments.
#Python
#Kubernetes API
#Scripting
Cloud Engineer
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Coding
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medium
Write a Go program that concurrently pings a list of 10,000 IP addresses (representing our worker nodes) and returns the IPs that are unreachable. Ensure your solution is highly concurrent but does not exceed OS file descriptor limits.
#Go
#Goroutines
#Channels
#Networking
Cloud Engineer
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Coding
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hard
Implement a token bucket rate limiter in Python or Go. Explain how you would adapt this to work across a distributed cluster of API gateways.
#Rate Limiting
#Distributed Systems
#Redis
Cloud Engineer
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Coding
•
medium
Write a Python script to parse a massive stream of distributed logs, identify spikes in specific HTTP 5xx errors, and output the top 3 offending IP addresses.
#Python
#Log Parsing
#Data Structures
#Streaming
Cloud Engineer
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Coding
•
medium
Implement a task scheduler that takes a list of tasks with dependencies and executes them in the correct order. If a cycle is detected, throw an error.
#Graphs
#Topological Sort
#DFS/BFS
Cloud Engineer
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Coding
•
medium
Write a Go program to concurrently fetch health check endpoints of 10,000 internal services. It should timeout after 5 seconds and return a list of failed services.
#Go
#Goroutines
#Channels
#Context
Cloud Engineer
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Coding
•
medium
Given a list of IP CIDR blocks, write a function to merge all overlapping blocks and return the minimized list of CIDRs.
#Intervals
#Networking
#Python/Go
Cloud Engineer
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Coding
•
medium
Write a script that automatically cordons and drains Kubernetes nodes if a specific Prometheus alert (e.g., hardware failure) fires for more than 5 minutes.
#Kubernetes API
#Python/Go
#Prometheus
Cloud Engineer
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Coding
•
easy
Implement a basic load balancer algorithm in code that routes requests to a pool of backend servers using Weighted Round Robin.
#Load Balancing
#Data Structures
#Math
Cloud Engineer
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Coding
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hard
Write a function to find the shortest path in a network of microservices to identify the root cause of a cascading failure, given a graph of service dependencies and their current error rates.
#Graphs
#Dijkstra
#BFS
Cloud Engineer
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Coding
•
easy
Write a script to validate that a given JSON configuration file for cloud infrastructure strictly adheres to a predefined schema, handling nested objects and arrays.
#JSON
#Validation
#Recursion
Cloud Engineer
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System Design
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hard
Design a system to provision, manage, and monitor a cluster of 10,000 GPUs on Azure for a massive LLM training run. How do you handle node failures gracefully without restarting the entire training job?
#Azure
#Kubernetes
#GPU Orchestration
#Fault Tolerance
Cloud Engineer
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System Design
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hard
Design an auto-scaling architecture for the ChatGPT inference API that experiences sudden, massive spikes in traffic. How do you scale stateful workloads like KV-cache across multiple regions?
#Auto-scaling
#Load Balancing
#Distributed Systems
#Inference
Cloud Engineer
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System Design
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hard
Design a CI/CD pipeline for deploying updates to a mission-critical Kubernetes cluster that serves model inference, ensuring zero downtime and the ability to roll back instantly if error rates spike.
#GitOps
#ArgoCD
#Canary Deployments
#Observability
Cloud Engineer
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System Design
•
hard
Design a rate-limiting service for the OpenAI API that can handle sudden, massive viral spikes in traffic across multiple global regions.
#Distributed Systems
#API Gateway
#Redis
#Concurrency
Cloud Engineer
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System Design
•
hard
Explain how you would design the infrastructure to serve a large language model like GPT-4, ensuring high availability and low latency for global users.
#GPU Orchestration
#Load Balancing
#High Availability
#Inference
Cloud Engineer
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System Design
•
hard
Design a telemetry and observability system capable of ingesting and querying metrics from 100,000+ GPUs in real-time.
#Observability
#Prometheus
#Time-Series Databases
#Scaling
Cloud Engineer
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System Design
•
hard
Design a distributed caching layer for LLM embeddings that allows fast nearest-neighbor lookups across billions of vectors.
#Vector Databases
#Caching
#Distributed Systems
Cloud Engineer
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System Design
•
medium
Design a scalable CI/CD pipeline for a massive monorepo containing both infrastructure code and machine learning models.
#CI/CD
#Monorepo
#Bazel
#Automation
Cloud Engineer
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System Design
•
hard
Design a system to securely stream massive training datasets (petabytes of data) from cloud storage to thousands of GPU nodes in real-time.
#Storage
#Throughput
#Distributed Systems
Cloud Engineer
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System Design
•
hard
Design a multi-region active-active deployment architecture for the OpenAI API to ensure 99.99% uptime.
#High Availability
#Global Routing
#Database Replication
Cloud Engineer
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Technical
•
hard
You notice a high rate of packet drops on a Linux node running heavy GPU inference workloads. Walk me through the tools and steps you would use to diagnose if the bottleneck is at the NIC, the kernel network stack, or the application.
#Linux
#Networking
#Performance Tuning
#eBPF
Cloud Engineer
•
Technical
•
medium
We use Terraform heavily to manage our Azure infrastructure. How would you structure the Terraform state and modules to allow dozens of infrastructure and research teams to deploy concurrently without locking each other out or causing state corruption?
#Terraform
#Azure
#CI/CD
#State Management
Cloud Engineer
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Technical
•
hard
Explain how you would configure Azure ExpressRoute and VNet peering to ensure secure, ultra-low-latency communication between our training clusters and our massive blob storage accounts.
#Azure Networking
#ExpressRoute
#VNet
#Security
Cloud Engineer
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Technical
•
hard
Model checkpointing generates terabytes of data in seconds. How would you design the storage layer in Azure to handle this massive write burst throughput without bottlenecking the GPU training process?
#Azure Blob Storage
#Lustre
#High Performance Computing
#IOPS
Cloud Engineer
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Technical
•
medium
How would you design the Azure RBAC and Kubernetes RBAC policies to ensure that researchers have full access to their specific training namespaces but cannot access, view, or modify production inference workloads?
#IAM
#Kubernetes RBAC
#Azure AD
#Least Privilege
Cloud Engineer
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Technical
•
medium
How do you troubleshoot a scenario where pods in a Kubernetes cluster can communicate with each other perfectly, but intermittently drop connections when reaching out to an external Azure managed database?
#Kubernetes
#SNAT
#DNS
#Troubleshooting
Cloud Engineer
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Technical
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hard
How does packet flow work between two pods on different nodes in a Kubernetes cluster? Walk me through the exact networking path.
#Kubernetes
#CNI
#Linux Networking
#iptables/eBPF
Cloud Engineer
•
Technical
•
medium
We use Azure heavily. Explain the difference between Azure Virtual Network Peering and ExpressRoute, and when you would use each for a hybrid cloud training cluster.
#Azure
#Networking
#Hybrid Cloud
Cloud Engineer
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Technical
•
medium
How do you manage Terraform state in a large organization where multiple engineers and CI/CD pipelines are applying changes simultaneously?
#Terraform
#CI/CD
#State Management
Cloud Engineer
•
Technical
•
hard
A Kubernetes node is showing high GPU memory utilization but 0% GPU compute utilization. How do you troubleshoot this?
#GPUs
#Kubernetes
#Nvidia SMI
#Linux
Cloud Engineer
•
Technical
•
hard
Explain the Raft consensus algorithm and how etcd uses it. What are the bottlenecks when scaling etcd to thousands of Kubernetes nodes?
#etcd
#Raft
#Kubernetes Internals
Cloud Engineer
•
Technical
•
hard
How would you implement zero-downtime node upgrades in a stateful Kubernetes cluster running distributed ML training jobs?
#Kubernetes
#StatefulSets
#Operations
Cloud Engineer
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Technical
•
hard
What is RDMA (Remote Direct Memory Access) and why is it critical for distributed GPU training clusters?
#RDMA
#InfiniBand
#GPUs
#Performance
Cloud Engineer
•
Technical
•
medium
Explain what an OOMKilled event is in Kubernetes. How do you determine if it was caused by the container exceeding its limit or the node running out of memory?
#Kubernetes
#Linux
#Memory Management
Cloud Engineer
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Technical
•
medium
How do you handle secret management and rotation across multiple Kubernetes clusters in different cloud regions?
#Security
#HashiCorp Vault
#Kubernetes
Cloud Engineer
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Technical
•
hard
You are tasked with writing a Kubernetes Custom Resource Definition (CRD) and Operator to manage the lifecycle of a proprietary ML training job. Walk me through the architecture.
#Kubernetes
#Operators
#Go
Cloud Engineer
•
Technical
•
medium
How would you implement autoscaling for a Kubernetes cluster based on a custom metric, such as the length of a GPU job queue?
#Kubernetes
#Autoscaling
#Prometheus
Cloud Engineer
•
Technical
•
medium
What are the primary bottlenecks when pulling massive Docker images (e.g., 20GB+ Python ML environments) across thousands of nodes simultaneously, and how do you mitigate them?
#Docker
#Containerd
#Networking
#P2P
Cloud Engineer
•
Technical
•
hard
Explain how you would secure a multi-tenant Kubernetes cluster where different research teams are running arbitrary code.
#Kubernetes
#Security
#Isolation
Cloud Engineer
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Technical
•
hard
Troubleshoot a scenario where DNS resolution latency inside a large Kubernetes cluster is sporadically spiking to over 5 seconds.
#DNS
#Kubernetes
#CoreDNS
#Linux
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