All 51 questions

  1. How would you validate data integrity and prove no data was lost during a migration?

    Asked in 7 of 307 interviews · last asked Sep 18 · Scenario · Mid-level

    Show answer

    I would compare the source and target at the same snapshot or cutoff time. I would reconcile row counts and every record key, then compare values using the expected transformation rules. I would also check duplicates, nulls, and broken relationships. Before sign-off, I would confirm all changes through the cutoff were applied and save the reconciliation results.

    • Matching counts alone cannot prove no data was lost; compare keys and values too.
    • Check required fields, unique keys, and relationships against agreed rules.
    • Track rejected rows and failed batches; resolve every unexplained difference.
    • Capture ongoing source changes and reconcile through a clear final cutoff.

    What the interviewer checks: The interviewer checks whether you can show complete, correct migration results with repeatable checks and saved evidence.

    Other ways it was asked
    • “How would you monitor data quality during a migration?”
    • “How do you validate data quality during a data migration?”
    • “How do you ensure data quality during a data migration?”

  2. What factors can motivate moving Apache NiFi from on-premises infrastructure to the cloud, and what challenges might arise?

    Asked once · last asked Feb 6 · Scenario · Mid-level

  3. What would you want to understand before migrating R pipelines to dbt or PostgreSQL?

    Asked once · last asked Sep 9 · Scenario · Mid-level

    Other ways it was asked
    • “What would you assess, and what issues would you look for, when migrating R pipelines to dbt or PostgreSQL?”
    • “How would you approach migrating an R data pipeline to PostgreSQL?”

  4. How do you decide whether to transform data formats when migrating data to Amazon S3?

    Asked once · last asked Mar 3 · Scenario · Mid-level

  5. When migrating data, how do you decide whether to ingest the full dataset or simplify it beforehand?

    Asked once · last asked Mar 6 · Scenario · Mid-level

  6. How would you check database tables for missing data and compare migrated data with the source file?

    Asked once · last asked Mar 6 · Scenario · Mid-level

  7. When migrating from Postgres to MySQL, how would you propagate CDC changes to keep the target system in sync?

    Asked once · last asked Mar 20 · Design · Senior

  8. How can you validate data integrity during a cloud migration using checksums or comparisons of the actual data?

    Asked once · last asked Apr 14 · Concept · Mid-level

  9. How would you migrate data from Google Cloud Storage to Amazon S3?

    Asked once · last asked May 21 · Scenario · Senior

  10. What discovery questions would you ask a customer modernizing an on-premises Hadoop platform with an 18-month Cloudera deadline and no data lineage?

    Asked once · last asked Jul 16 · Scenario · Senior

  11. What is the difference between data migration and data integration?

    Asked once · last asked Jul 16 · Concept · Mid-level

  12. How would you migrate a large dataset to AWS?

    Asked once · last asked Jul 16 · Scenario · Senior

    Other ways it was asked
    • “Assume you have to migrate 10 TB of data from Oracle to AWS. How would you do it?”

  13. How would you optimize the migration of a large dataset using PySpark?

    Asked once · last asked Jul 16 · Scenario · Senior

  14. How would you migrate data between Odoo versions, such as from version 18 to version 19?

    Asked once · last asked Jul 23 · Scenario · Senior

  15. How would you migrate 500 million or more records without downtime or data loss?

    Asked once · last asked Jul 27 · Design · Senior

  16. When performing a data migration for a large-scale system upgrade on a trading platform involving millions of historical transaction records, what is your systematic SQL-based approach?

    Asked once · last asked Jul 28 · Scenario · Senior

  17. What are the key stages and responsibilities in a database-to-cloud migration?

    Asked once · last asked Aug 12 · Scenario · Mid-level

  18. How do you perform a data migration? Give me the step-by-step process and the tools used.

    Asked once · last asked Aug 16 · Scenario · Mid-level

  19. How would you approach migrating a data warehouse from Teradata to Snowflake?

    Asked once · last asked Aug 20 · Scenario · Senior

  20. How would you validate that data pipelines migrated to a new data warehouse are correct?

    Asked once · last asked Aug 20 · Scenario · Senior

  21. Suppose we needed to move hundreds of terabytes of data between platforms, for example from Snowflake on AWS to Microsoft Fabric on Azure. How would you design the migration while controlling cost, maintaining security, and validating the data?

    Asked once · last asked Aug 31 · Design · Senior

  22. When would you use Azure Data Factory or Microsoft Fabric rather than Databricks or Spark for a large historical migration from Snowflake into Fabric Delta tables?

    Asked once · last asked Aug 31 · Tooling · Senior

  23. What key elements do you consider when planning an SAP data migration?

    Asked once · last asked Sep 1 · Case · Mid-level

  24. How do you migrate from a JSON blob per user to a relational model for analytics?

    Asked once · last asked Sep 3 · Scenario · Senior

  25. How would you migrate data for a live service?

    Asked once · last asked Sep 4 · Scenario · Senior

  26. How would you approach a Tableau-to-Power BI migration involving multiple data sources and existing parameters?

    Asked once · last asked Sep 9 · Scenario · Senior

  27. Where would you focus when testing a data pipeline migration to prevent application breakage?

    Asked once · last asked Sep 9 · Scenario · Mid-level

  28. How would you migrate a data transformation from PySpark on Dataproc to BigQuery?

    Asked once · last asked Sep 10 · Scenario · Mid-level

  29. How would you migrate nonstandardized Snowflake data on AWS to Azure using CDC while decoupling reporting from ERP systems?

    Asked once · last asked Sep 16 · Design · Senior

  30. What would be your strategy to migrate five terabytes of data from on-premises to the cloud?

    Asked once · last asked Sep 16 · Scenario · Senior

  31. How would you migrate data with minimal downtime and reliable rollback? Briefly explain your step-by-step approach, including how you would load records, preserve Account–Contact relationships, and safely retry failed rows without creating duplicates.

    Asked once · last asked Sep 17 · Scenario · Senior

  32. How would you plan data mapping, cutover, and rollback for migrating a heavily customized legacy CRM to Salesforce with minimal downtime?

    Asked once · last asked Sep 18 · Design · Senior

  33. Tell me about a data migration or platform modernization initiative you worked on, your responsibilities, and how you ensured it was ready for downstream users.

    Asked once · last asked Sep 20 · Behavioral · Senior

  34. How would you migrate millions of records from a legacy CRM to Salesforce, and how would you model and store very large data volumes in Salesforce?

    Asked once · last asked Sep 21 · Design · Senior

  35. How would you plan data migration and database architecture during a technology-stack migration?

    Asked once · last asked Sep 21 · Scenario · Senior

  36. During a Microsoft Fabric migration, how would you investigate an undocumented transformation rule that changes an important report before deciding whether to reproduce or remove it?

    Asked once · last asked Sep 21 · Scenario · Senior

  37. How would you migrate an on-premises Oracle database, including its data and objects, to Snowflake?

    Asked once · last asked Sep 22 · Design · Senior

  38. Which integration option would you prefer for moving patient data from the legacy system into Salesforce?

    Asked once · last asked Sep 30 · Scenario · Senior

  39. When you need to perform a large Salesforce data cleanup or migration, how do you plan the import/update tool choice, mapping strategy, validation, and rollback plan to minimize business disruption?

    Asked once · last asked Oct 1 · Scenario · Senior

  40. If record counts and overall totals match after a migration but some individual values differ slightly, how would you decide whether the migration was acceptable?

    Asked once · last asked Oct 1 · Scenario · Mid-level

  41. How would you organize a Python script for migrating data to ClickHouse into modules or functions, and what systems would it interact with?

    Asked once · last asked Oct 1 · Tooling · Mid-level

  42. How would you design a migration and select users for efficient processing at a scale of one trillion users?

    Asked once · last asked Oct 6 · Design · Senior

  43. How would you approach a migration to SAP Datasphere?

    Asked once · last asked Oct 6 · Scenario · Senior

  44. When migrating data, how do you decide which code to write yourself and which to generate with AI?

    Asked once · last asked Oct 9 · Tooling · Mid-level

  45. How do you monitor data integrity, flag issues, and ensure integrity is preserved when migrating from a legacy system to a new system?

    Asked once · last asked Oct 9 · Scenario · Mid-level

    Other ways it was asked
    • “How do you track and flag data integrity, and ensure it is preserved when moving from the legacy system to the new system?”

  46. What challenges can arise when migrating from BMC Remedy to ServiceNow?

    Asked once · last asked Oct 13 · Scenario · Senior

  47. How would you ensure a smooth migration from a legacy system to ServiceNow, including complex historical records and attachments?

    Asked once · last asked Oct 22 · Scenario · Senior

  48. How would you migrate data and synchronize with ClickBank without losing data or causing downtime?

    Asked once · last asked Oct 22 · Design · Senior

  49. How would you migrate from MySQL to PostgreSQL and synchronize user data without data loss or downtime?

    Asked once · last asked Oct 22 · Design · Senior

  50. Which cloud storage service would you choose for a large data migration, and why?

    Asked once · last asked May 21 · Scenario · Mid-level

  51. How would you describe the source-to-destination data flow in a data migration?

    Asked once · last asked Jul 16 · Scenario · Mid-level

More ETL and Data Pipelines interview questions

How this list is made

Every question here was asked by a real interviewer in a real job interview that a candidate ran MeetAssist in. After the call, the interviewer's questions are pulled from the transcript. Practice sessions, tests, exams and anything that was not a job interview are dropped.

Questions are rewritten so they make sense on their own: names of people, employers and clients are removed, and speech-to-text mistakes are fixed. Small talk, logistics and questions about one candidate's own résumé are left out. Rephrasings of the same question are merged, and the count is the number of different interviews it came up in.

The interviews come from candidates who use MeetAssist, so they lean towards software, data and AI roles: the shares describe these interviews, not every ETL and Data Pipelines interview. Answers to the most asked questions are written and checked by an editor; a "common mistake" is shown only when reviews of real answers in these interviews show it, with the count.

307 interviews, 169 candidates, Nov 2025 to Oct 2026. Updated every month with new interviews.