Practice Problems

Realistic AI engineering scenarios with reference solutions and problem-specific grading rubrics.

39 problems

ProblemCategoryDifficultyTimeBest

Design a URL Shortener
Capacity estimation · Key generation · Caching · Read-heavy systems
ML System DesignEasy35 minEasy35m–Design
Diagnose Model Drift
Drift Analysis · Root Cause Analysis · Covariate Shift · Concept Drift

Design a Demand Forecasting Platform

Time Series · Hierarchical Forecasting · Backtesting · Intermittent Demand

ML System DesignMedium40 minMedium40m–Design

Design a Large-Scale Classification Platform

Extreme Multi-Label · Hierarchical Classification · Active Learning · Human-in-the-Loop

ML System DesignMedium40 minMedium40m–Design

Design a Predictive Maintenance System

Sensor Data · Survival Analysis · Rare Events · Edge Inference · Time Windows

ML System DesignMedium40 minMedium40m–Design

Design a Real-Time Anomaly Detection System

Time Series · Unsupervised Learning · Streaming · Alerting · Seasonality

ML System DesignMedium40 minMedium40m–Design

Design a Recommendation System

Candidate Generation · Ranking · Embeddings · Two-Tower Models · Cold Start

ML System DesignMedium45 minMedium45m–Design

Design an Image Search System

Vision Embeddings · ANN Search · Multimodal · Index Sharding · CLIP

ML System DesignMedium40 minMedium40m–Design

Design an ML Training Pipeline

Pipelines · Reproducibility · Experiment Tracking · Data Versioning · Orchestration

ML System DesignMedium35 minMedium35m–Design

Design Feature Monitoring

Data Quality · Skew Detection · Lineage · Freshness SLAs · Root Cause

ML System DesignMedium30 minMedium30m–Design

Design Model Monitoring

Drift Detection · Delayed Labels · Alerting · Segment Analysis · Observability

ML System DesignMedium35 minMedium35m–Design

Diagnose Training-Serving Skew

Skew Debugging · Feature Pipelines · Data Leakage · Root Cause Analysis

ML System DesignMedium30 minMedium30m–Design

Improve a Low-Recall Model

Imbalanced Data · Threshold Tuning · Error Analysis · Precision-Recall Tradeoff

ML System DesignMedium30 minMedium30m–Design

Debug a Production ML Model

Incident Response · Root Cause Analysis · Debugging · Systems Thinking

ML System DesignHard35 minHard35m–Design

Design a Model Serving Platform

Model Serving · GPU Scheduling · Autoscaling · Canary Deploys · Multi-tenancy

ML System DesignHard45 minHard45m–Design

Design a Personalized News Feed

Ranking · Fan-out · Multi-Objective Optimization · Freshness · Feedback Loops

ML System DesignHard45 minHard45m–Design

Design a Real-Time Fraud Detection System

Streaming · Imbalanced Data · Feature Store · Low Latency · Adversarial ML

ML System DesignHard50 minHard50m–Design

Design a Search Ranking System

Learning to Rank · BM25 · Query Understanding · Click Models · Position Bias

ML System DesignHard45 minHard45m–Design

Design an Ad Ranking System

CTR Prediction · Auctions · Calibration · Delayed Feedback · Budget Pacing

ML System DesignHard50 minHard50m–Design

Design an ML Feature Store

Feature Store · Point-in-Time Correctness · Streaming · Data Engineering

ML System DesignHard45 minHard45m–Design

Design Continuous ML Deployment

CI/CD · Canary Analysis · Shadow Deploys · Rollback · Automated Promotion

ML System DesignHard40 minHard40m–Design

Design a ChatGPT-like Application

Streaming · Context Management · Conversation State · Safety · Cost Control

LLM System DesignMedium40 minMedium40m–Design

Design a Self-Serve LLM Fine-Tuning Platform

GPU scheduling · Model registry · LoRA · Eval gating · Multi-tenancy

LLM System DesignMedium40 minMedium40m–Design

Design an LLM Gateway

API Gateway · Rate Limiting · Caching · Observability · Failover

LLM System DesignMedium40 minMedium40m–Design

Design an LLM Evaluation Platform

LLM-as-Judge · Eval Design · Regression Testing · Human Labeling · Statistics

LLM System DesignHard45 minHard45m–Design

Design an LLM Inference Serving System

Continuous batching · KV cache · GPU autoscaling · Quantization · Latency budgets

LLM System DesignHard45 minHard45m–Design

Design a Document Intelligence Platform

OCR · Structured Extraction · Confidence Calibration · Human Review · Multimodal

RAGMedium40 minMedium40m–Design

Design a Semantic Search System

Embeddings · Hybrid Search · Chunking · Reranking · Index Design

RAGMedium35 minMedium35m–Design

Design a Production RAG System

RAG · Embeddings · Vector DB · Reranking · LLM Evaluation · Access Control

RAGHard45 minHard45m–Design

Design an Enterprise Knowledge Assistant

RAG · Tool Use · Personalization · Enterprise Integration · Guardrails

RAGHard45 minHard45m–Design

Design an AI Agent for Customer Refunds

Tool calling · Irreversible actions · Policy enforcement · Escalation

AI AgentsMedium40 minMedium40m–Design

Design a Tool-Calling Agent Over 500 APIs

Tool selection · Retrieval · Permissions · Failure handling · Observability

AI AgentsHard45 minHard45m–Design

Design an AI Coding Assistant

Code Context · Low Latency · Fill-in-the-Middle · Repo Indexing · Acceptance Metrics

AI AgentsHard45 minHard45m–Design

Design an AI Customer Support Agent

Agents · Tool Use · Escalation · Safety · Containment Rate

AI AgentsHard45 minHard45m–Design