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Comprehensive Interview Preparation Guide: Junior Data Engineer at Airbnb

Data Engineer
Airbnb
Junior
6 rounds
Updated 6/20/2026

Airbnb's data engineer interview process is structured to assess technical proficiency, problem-solving abilities, and cultural fit. For a junior level position, candidates progress through a recruiter screening, a technical phone screen, and a comprehensive onsite interview loop consisting of four technical and behavioral rounds. The entire process spans 3-5 weeks and evaluates SQL and Python competency, ETL pipeline design thinking, system architecture understanding, and alignment with Airbnb's mission of belonging and community.

Interview Rounds

1

Recruiter Screening

2

Technical Phone Screen

3

Onsite Round 1: SQL and Data Analysis Deep Dive

4

Onsite Round 2: Python/Spark and Data Processing

5

Onsite Round 3: ETL Pipeline Design and System Architecture

6

Onsite Round 4: Behavioral and Cultural Fit

Frequently Asked Data Engineer Interview Questions

Batch and Stream ProcessingMediumTechnical
85 practiced
You observe hot partitions in Kafka because a small set of keys receives disproportionate traffic, causing skewed consumer lag and uneven processing. Describe techniques to mitigate hot-key problems in producers, brokers, and consumers, and discuss trade-offs and ordering implications for each approach.
Big Data Technologies Apache SparkHardTechnical
43 practiced
You see java.io.NotSerializableException or Task not serializable errors in a Spark job. Explain common causes such as capturing non-serializable objects in closures, referencing driver-only instances, or using lambda-captured outer class state. Describe concrete debugging steps and fixes for both Scala and PySpark codebases.
Advanced SQL Window FunctionsHardTechnical
59 practiced
Cohort retention with reactivation: Given users(user_id, signup_date) and events(user_id, event_date), compute a rolling 12-week retention table that treats reactivated users as 'retained' in the week they reappear but only counts unique users once per cohort-week. Use window functions and, if necessary, recursive CTEs to handle complex reactivation patterns. Explain your SQL and edge cases.
Data Architecture and PipelinesHardTechnical
56 practiced
Plan a migration from an on-prem Hadoop ecosystem (HDFS, Hive, Oozie) to a cloud-native lakehouse (object storage + Iceberg/Delta + Airflow/Kubernetes). Provide a phased migration plan with data replication approach, validation and reconciliation steps, cutover strategy with minimal downtime, rollback plan, and how to preserve lineage and access controls.
Advanced Querying with Structured Query LanguageEasyTechnical
21 practiced
Write a SQL query that returns, per user, the total, average, minimum, maximum, and count of transaction amounts over the last 90 days. Given the table schema transactions(transaction_id BIGINT PRIMARY KEY, user_id BIGINT, amount DECIMAL(10,2), occurred_at TIMESTAMP). Only include users with at least 3 transactions in the period, order by total descending, and explain how you handle NULL amounts and timezone assumptions. Use Postgres-compatible SQL.
Batch and Stream ProcessingEasyTechnical
88 practiced
Define event time and processing time in stream processing and explain why event-time processing matters. Provide a concrete example where aggregations computed on processing time give wrong results when events are delayed, and describe how event-time + watermarks addresses the problem.
Big Data Technologies Apache SparkMediumTechnical
57 practiced
Describe how to achieve exactly-once semantics in Structured Streaming when writing to external systems such as Kafka and HDFS/Parquet. Explain the role of checkpointing, transactional sinks (Kafka transactions), idempotent writes, and trade-offs when sink does not support transactions.
Advanced SQL Window FunctionsMediumTechnical
77 practiced
You have a multi-step report implemented as multiple GROUP BYs and self-joins that compute per-customer KPIs and then attach them to each transaction row. Rewrite the logic using window functions to simplify the query, and explain the performance trade-offs between the two approaches.
Data Architecture and PipelinesHardSystem Design
56 practiced
Design a real-time anomaly detection pipeline over streaming metrics with SLA of alert delivery within 2 seconds. The system must minimize false positives and provide explainable alerts. Describe ingestion, feature computation, model serving (stateless vs stateful), thresholding or probabilistic detectors, human feedback loop, and scaling strategies.
Advanced Querying with Structured Query LanguageEasyTechnical
18 practiced
You have table events(event_pk SERIAL PRIMARY KEY, user_id INT, event_id TEXT, created_at TIMESTAMP, payload JSONB). Some event rows are duplicates for the same (user_id, event_id). Write a Postgres SQL statement using a window function to delete duplicates and keep only the latest row per (user_id, event_id). Provide a safe CTE-based delete pattern suitable for production.
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