TCS Data Analyst Interview Questions (2026)

1. 1TCS NQT60 minMedium

   Online qualifier on TCS iON covering numerical/verbal/reasoning ability plus a coding section; the cutoff and score band route candidates to Ninja, Digital, or Prime interviews.

2. 2Technical Round (TR)40 minMedium

   Panel probes CS fundamentals (OOP, DBMS, OS basics), the candidate's final-year or work projects, and one or two simple programs written live; laterals get grilled on their claimed stack.

3. 3Digital/Prime Coding Interview45 minHard

   For Digital and Prime track candidates, a harder round with DSA problems, code optimization, and questions on cloud or newer technologies.

4. 4Managerial Round (MR)30 minMedium

   A senior manager tests composure with scenario and mild stress questions — missed deadlines, disagreement with a lead, willingness to work in any technology or location.

5. 5HR Round25 minEasy

   Discussion of the service agreement, relocation and shift flexibility, salary structure, and background verification documents.

1. Q1

   Write a SQL query to find duplicate customer records in TCS's banking client's loan-portfolio reporting. How would you decide which record survives?

   MediumSQL roundduplicate detectionTCS-specific

   Context:

   TCS banking client's loan-portfolio reporting

   How to answer:

   Use GROUP BY/HAVING or ROW_NUMBER over a business key, define survivorship rules, and push the fix upstream. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

2. Q2

   Using window functions, how would you add a 7-day rolling total and a rank within category to TCS's retail client's daily sales dashboard?

   MediumSQL roundwindow functionsTCS-specific

   Context:

   TCS retail client's daily sales dashboard

   How to answer:

   Contrast aggregate vs window behavior, frame clauses, and partition choices. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

3. Q3

   Your XLOOKUP against the master sheet in TCS's banking client's loan-portfolio reporting returns #N/A for valid IDs. What do you check?

   MediumExcel and BI roundlookupsTCS-specific

   Context:

   TCS banking client's loan-portfolio reporting

   How to answer:

   Trailing spaces, number-vs-text types, exact match mode, and TRIM/VALUE cleanup. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

4. Q4

   Build a pivot summary for TCS's retail client's daily sales dashboard: what goes in rows, values, and filters, and when does a pivot beat formulas?

   MediumExcel and BI roundpivot tablesTCS-specific

   Context:

   TCS retail client's daily sales dashboard

   How to answer:

   Structure the source as a flat table, choose aggregations, and know pivot refresh limits. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

5. Q5

   In Power BI, when does TCS's insurance client's claims data mart need a DAX measure instead of a calculated column?

   HardExcel and BI roundDAX measuresTCS-specific

   Context:

   TCS insurance client's claims data mart

   How to answer:

   Row context vs filter context, storage cost, and totals that only measures get right. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

6. Q6

   Design the Power BI model for TCS's e-commerce client's returns analysis: which tables are facts, which are dimensions, and why not one flat table?

   MediumExcel and BI rounddata modelingTCS-specific

   Context:

   TCS e-commerce client's returns analysis

   How to answer:

   Star schema, relationship directions, and what breaks when everything is one wide table. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

7. Q7

   The client says the TCS dashboard for healthcare client's appointment no-show reporting takes a minute to load. How do you make it fast?

   MediumExcel and BI rounddashboard performanceTCS-specific

   Context:

   TCS healthcare client's appointment no-show reporting

   How to answer:

   Reduce cardinality, trim visuals, pre-aggregate, and measure before optimizing. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

8. Q8

   Which KPIs go on the first screen of TCS's logistics client's delivery SLA tracking, and what do you deliberately leave out?

   MediumExcel and BI rounddashboard designTCS-specific

   Context:

   TCS logistics client's delivery SLA tracking

   How to answer:

   Lead with decisions the client makes weekly; park detail in drill-throughs. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

9. Q9

   Returns are rising in TCS's telecom client's churn reporting. Turn the data into a recommendation the client can act on this quarter.

   MediumAnalytics case roundbusiness recommendationTCS-specific

   Context:

   TCS telecom client's churn reporting

   How to answer:

   Segment the problem, size each driver, and attach an owner and expected impact to the fix. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

10. Q10

    For TCS's e-commerce client's returns analysis, when would you report the median instead of the mean, and how do you explain the gap to the client?

    MediumStatistics and metrics roundmean vs medianTCS-specific

    Context:

    TCS e-commerce client's returns analysis

    How to answer:

    Skew and outliers; show both when the story depends on the tail. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

11. Q11

    The client can only share a sample of records from TCS's logistics client's delivery SLA tracking. What do you check before trusting conclusions?

    MediumStatistics and metrics roundsampling and biasTCS-specific

    Context:

    TCS logistics client's delivery SLA tracking

    How to answer:

    How the sample was drawn, coverage of segments and time, and known exclusions. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

12. Q12

    Growth in TCS's banking client's loan-portfolio reporting is reported as +40%, but the client is suspicious. Which base-rate and mix effects do you check?

    HardStatistics and metrics roundpercentage change pitfallsTCS-specific

    Context:

    TCS banking client's loan-portfolio reporting

    How to answer:

    Small denominators, mix shift (Simpson's paradox), and period-boundary artifacts. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

13. Q13

    List the validation checks you run before the numbers for TCS's retail client's daily sales dashboard go to the client.

    MediumData quality roundpre-publish validationTCS-specific

    Context:

    TCS retail client's daily sales dashboard

    How to answer:

    Row counts vs source, totals reconciliation, duplicate and NULL checks, period completeness. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

14. Q14

    A stakeholder on TCS's e-commerce client's returns analysis asks for 'a report' with no further detail. What do you do before writing any query?

    EasyBehavioral/project discussionambiguous requirementsTCS-specific

    Context:

    TCS e-commerce client's returns analysis

    How to answer:

    Ask for the decision the report serves, sketch a mock, agree definitions, then build. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

15. Q15

    The client needs numbers from TCS's healthcare client's appointment no-show reporting today, but you know the data has issues. What do you send?

    EasyBehavioral/project discussiondeadline vs accuracyTCS-specific

    Context:

    TCS healthcare client's appointment no-show reporting

    How to answer:

    Ship with explicit caveats and scope, or cut scope — never silently ship known-bad numbers. State the business question, the data you would pull, and the checks that make the number trustworthy. Walk through the query or steps concretely, naming tables, joins, filters, and edge cases. Close with how you would validate the result and explain it to the stakeholder.

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