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Databricks·Software Engineer·Onsite - System Design / Architecture·Senior

Senior
Apr 2026

Summary

Databricks SWE interview with a system design question around building a document processing pipeline. Not a lot of context in what I have to share but it was a solid design problem that pushed me to think about scale and fault tolerance.

Questions Asked (1)

Q1

Design a document processing pipeline.

System DesignTechnical Trade-offsAPI & Integrations
Author's notes

This is the kind of question that feels straightforward until you start drawing boxes and realize you haven't thought about what happens when a document fails halfway through.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and scale, then propose a high-level architecture that leverages Databricks' Lakehouse platform (Delta Lake, Spark) for ingestion, processing, and serving. Focus on trade-offs between batch and streaming, and discuss how to ensure reliability, scalability, and cost-efficiency.

Pro tip: Emphasize how Delta Lake's ACID transactions and time travel simplify pipeline reliability and reproducibility, and mention how you'd use Databricks Workflows for orchestration and monitoring.

1. Clarify Requirements

Ask about data volume, velocity, variety, latency requirements, and use cases (e.g., analytics, ML). Confirm SLAs and budget constraints.

2. High-Level Architecture

Outline stages: ingestion (batch/streaming), storage (Delta Lake), processing (Spark), and serving (BI, ML). Mention Databricks components like Auto Loader, Structured Streaming, and MLflow.

3. Deep Dive into Key Components

Discuss ingestion patterns (e.g., Auto Loader for incremental files), processing (batch vs. streaming, medallion architecture), and storage optimizations (partitioning, Z-ordering).

4. Address Trade-offs and Scalability

Compare batch vs. streaming, cost vs. latency, and how to scale (e.g., autoscaling clusters, Delta Engine). Discuss failure handling and exactly-once semantics.

5. Monitoring and Governance

Explain how to monitor pipeline health (Databricks Jobs UI, metrics), ensure data quality (expectations, Delta constraints), and implement governance (Unity Catalog).

Key Points to Mention

  • Delta Lake for ACID transactions, schema enforcement, and time travel
  • Medallion architecture (bronze, silver, gold) for data quality and organization
  • Auto Loader for efficient incremental ingestion
  • Structured Streaming for real-time processing with exactly-once guarantees
  • Databricks Workflows for orchestration and scheduling
  • Cost optimization via cluster autoscaling and photon runtime

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.