LTIMindtree Power BI Interview Questions & Answers
Curated interview practice questions with answers. These are practice scenarios, not a verified list of past interview questions.
About LTIMindtree hiring for Power BI roles
LTIMindtree is an Indian IT services and consulting company formed by the merger of Larsen and Toubro Infotech and Mindtree, and part of the L&T Group. It provides cloud, data, ERP, testing and digital engineering services for global clients. It hires for software engineers, test engineers, data analysts, data engineers and ERP consultants.
For Power BI roles, this LTIMindtree practice set focuses most on Visualisation and Report Design (7), DAX Fundamentals (6), Power BI Fundamentals (6), Power Query and Data Transformation (4). It has 8 easy, 21 medium, 1 hard questions, so you can start easy and work up to the harder ones.
Company type
IT services
Headquarters
Mumbai, India
Main India offices
Mumbai, Pune, Bengaluru, Chennai, Hyderabad
LTIMindtree Power BI interview process
Online assessment (aptitude + reasoning)
Coding test
Technical interview
HR round
Typical pattern based on public candidate experiences. Rounds vary by role, team and year.
Solved for LTIMindtreeStart practicing
3 QUESTIONS FREESign up to unlock the full question bank and track your progress.Unlock every question and answer, then continue practising company-wise and package-wise.
✓ 3 questions free • Unlock the rest in seconds
01
What is the difference between Group By in Power Query and summarising in DAX?
Group By in Power Query aggregates rows at refresh time and stores only the summarised table, reducing model size, which is useful when detail is never needed. Summarising in DAX through measures keeps detail in the model and aggregates dynamically for any filter at query time. Use Power Query grouping for fixed summaries such as monthly snapshots, and DAX measures when users need flexible slicing.
02
Write a measure for percentage of grand total sales.
Sales % of Total =
DIVIDE(
[Total Sales],
CALCULATE([Total Sales], REMOVEFILTERS('Product'))
)
This gives each product's share of total across all products. Use ALLSELECTED('Product') instead if the denominator should respect slicer selections on products.
A semantic model, earlier called a dataset, is the published data model behind reports: tables, relationships, measures, hierarchies, security roles and refresh settings. Many reports can connect to one shared semantic model, which keeps business logic and numbers consistent across teams. Certified or promoted endorsements help users find trusted models. Build permission controls who can create new reports on it.
Bookmarks capture the current state of a report page, including filters, slicers, visual visibility and sort order. They are used for storytelling, toggling between chart and table views with buttons, creating custom navigation, and resetting filters. Combined with the selection pane, they show and hide visuals. Too many bookmarks become hard to maintain, so field parameters are often a simpler alternative for switching measures.
05
Explain the typical Power BI workflow from data to insight.
First connect to sources such as Excel, SQL Server or SharePoint and clean the data in Power Query. Then build a data model with relationships, ideally a star schema, and write DAX measures. Next design report visuals and interactions in Desktop. Publish to a workspace in the Power BI Service, set scheduled refresh through a gateway if needed, apply row-level security and share through an app or dashboard.
06
Your calculated columns have made the model huge. What do you do?
I would move simple row-level logic into Power Query or the source SQL, where it compresses better and can fold, and replace aggregations stored as columns with measures. High-cardinality columns such as concatenated keys or precise timestamps should be removed or split. Then check model size with VertiPaq Analyzer in DAX Studio to confirm which columns used the most memory.
07
Write basic measures for total sales, total cost and profit margin percentage.
Total Sales = SUM(Sales[Amount])
Total Cost = SUMX(Sales, Sales[Qty] * Sales[UnitCost])
Profit = [Total Sales] - [Total Cost]
Margin % = DIVIDE([Profit], [Total Sales])
Format Margin % as a percentage. Building measures on other measures keeps logic in one place and easy to change.
08
How do you create a measure-driven conditional colour?
Sales Colour =
VAR ach = DIVIDE([Total Sales], [Target])
RETURN
SWITCH(TRUE(),
ach < 0.9, "#D64550",
ach < 1, "#F2A93B",
"#2E9E5B")
In the visual, open conditional formatting for background or font colour, choose Format style Field value and select this measure.
09
What are Import, DirectQuery and Live Connection modes?
Import loads a compressed copy of data into the in-memory VertiPaq engine, giving the fastest queries but requiring refresh. DirectQuery sends queries to the source at view time, so data is current but performance depends on the source and some DAX is limited. Live Connection connects a report to an existing semantic model or Analysis Services model without its own model. Composite models mix Import and DirectQuery tables.
10
What is a decomposition tree and when is it useful?
The decomposition tree is an AI visual that lets users break down a measure across several dimensions in any order, for example splitting a sales drop by region, then category, then channel. It can also suggest the next split automatically using high value or low value analysis. It is useful for root-cause exploration by business users, though it is less suited to fixed reporting.
CALCULATE evaluates an expression in a modified filter context. Its filter arguments can add, replace or remove filters, for example CALCULATE([Total Sales], 'Product'[Category] = "Electronics") replaces any category filter with Electronics. It also performs context transition when used inside a row context, turning the current row into an equivalent filter. It is the most important function in DAX.
12
What is a disconnected table and how is it used for what-if analysis?
A disconnected table has no relationship to the model and is used to capture a user's choice through a slicer. For example, a Discount table from 0 to 30 percent created with GENERATESERIES, or the What-if parameter feature, lets a measure read SELECTEDVALUE(Discount[Value]) and calculate projected revenue. Since it does not filter facts, the measure decides how the selection is applied.
13
Sales data has region codes, while targets use region names. How do you combine them?
I would create or import a region mapping table with code and name, clean both sides by trimming spaces and fixing case, then merge in Power Query or better, build a Region dimension table with both columns and relate sales by code and targets by name to it. Unmatched rows should be checked using a left anti join so missing mappings are fixed rather than silently dropped.
Only one active relationship can exist between two tables along a filter path; additional relationships become inactive and appear as dashed lines. For example, Sales may have OrderDate and ShipDate both linked to Date, with OrderDate active. An inactive relationship is used only inside a measure with USERELATIONSHIP, such as CALCULATE([Sales], USERELATIONSHIP(Sales[ShipDate], 'Date'[Date])).
VAR defines a named value inside an expression and RETURN gives the final result. Variables make measures easier to read, avoid repeating the same calculation, which improves performance, and help debugging because you can return an intermediate variable. A variable is evaluated once in the context where it is defined, so its value does not change if later CALCULATE filters are applied.
A report theme is a JSON file that sets default colours, fonts, visual styles and backgrounds for all visuals. Using a company theme keeps reports consistent with brand guidelines and saves formatting time, since new visuals adopt it automatically. Themes can be built in Desktop's theme customiser or edited as JSON and shared across the team as a standard.
17
Your model has one wide flat table with 80 columns from an Excel export. How would you remodel it?
I would identify the grain, such as one row per order line, and split descriptive attributes into dimension tables like Customer, Product, Store and Date using Reference queries and Remove Duplicates on keys. The fact table keeps keys and numeric columns only. Then create one-to-many single-direction relationships. This reduces size, simplifies DAX and makes slicers faster and more reliable.
18
When would you use a custom visual and what are the risks?
Custom visuals from AppSource add chart types not built in, such as Gantt charts, sankey diagrams or advanced KPI cards. Risks include performance issues, limited support, export and accessibility gaps, and data security, since some visuals may call external services. Prefer certified visuals, check organisational policy, since admins can restrict them, and use built-in visuals where they meet the need.
19
How do you choose the right chart type in Power BI?
Match the chart to the question. Use bar or column charts to compare categories, line charts for trends over time, stacked bars for part-to-whole across few categories, scatter charts for relationships, maps only for true geographic patterns, cards and KPI visuals for single numbers, and tables or matrices when users need exact values. Avoid pie charts with more than four or five slices.
20
What is the difference between Power BI and Excel for reporting?
Excel is flexible for ad hoc analysis and small models but struggles with large data, version control and secure sharing. Power BI handles millions of rows with a compressed columnar engine, central semantic models, scheduled refresh, row-level security and interactive web and mobile sharing. They work together: Power Query and Power Pivot exist in both, and users can analyse Power BI models in Excel.
21
What is the difference between Reference and Duplicate in Power Query?
Duplicate copies all the steps of a query into a new independent query, so later changes to the original do not affect it. Reference creates a new query whose source is the output of the original, so it inherits any changes. Reference is useful for building several tables from one staging query, such as dimension tables from a cleaned sales table, while Duplicate is for experimenting separately.
22
How do you explain a data model to a non-technical stakeholder?
I use a simple analogy: the fact table is the list of transactions, and dimensions are the labels we use to slice them, like date, product and region. I show the model diagram with only main tables and explain that slicers work through these links. Then I demonstrate one visual changing when a slicer changes, which makes the idea concrete quickly.
23
How do you publish a report and share it with business users?
In Desktop, choose Publish and select a workspace. In the Service, set up the semantic model's credentials and scheduled refresh. Then create or update an app from the workspace, choose the reports and audiences, and grant access to user groups. Apps give consumers a clean, stable view while authors keep working in the workspace. Avoid sharing from My workspace for team content.
24
How do you control how visuals interact with each other?
By default, selecting a data point cross-filters or cross-highlights other visuals on the page. Use Format, Edit interactions to choose filter, highlight or none for each visual pair, for example stopping a slicer from affecting a target KPI card. Slicers can also be synced across pages with the Sync slicers pane. Clear interaction design prevents confusing behaviour.
Field parameters let report users switch which measure or dimension a visual shows using a slicer, for example choosing between Sales, Profit and Units, or switching the axis between Region and Category. They are created through Modeling, New parameter, Fields, which generates a calculated table. They reduce the number of duplicate visuals and bookmarks needed for dynamic reports.
26
What is Copilot in Power BI and what should you watch out for?
Copilot in Power BI uses generative AI to help create report pages, summarise visuals in narrative form, suggest DAX and answer questions about data in natural language. It needs supported capacity and tenant settings enabled by admins. Results depend heavily on a clean model with clear names, descriptions and synonyms, and outputs must be checked for correctness before sharing, especially generated DAX.
Row context means DAX is evaluating one row at a time, which happens in calculated columns and iterators like SUMX, so you can refer to column values of the current row. Filter context is the set of filters applied to the model from slicers, visual rows, columns and CALCULATE. Measures are evaluated in filter context. Row context does not filter the model unless converted by context transition.
28
What is the difference between SAMEPERIODLASTYEAR, DATEADD and PARALLELPERIOD?
SAMEPERIODLASTYEAR shifts the current dates back exactly one year. DATEADD shifts by any number of days, months, quarters or years, such as DATEADD('Date'[Date], -1, MONTH) for last month. PARALLELPERIOD also shifts by an interval but returns the full shifted period, for example the whole previous quarter even if only one month is selected. Choose based on whether partial periods should be compared.
Query folding is when Power Query translates transformation steps into a native source query, such as SQL, so the source does the work and only the result is loaded. It makes refreshes much faster and is required for incremental refresh and efficient DirectQuery. Steps like filtering, removing columns and grouping usually fold on SQL sources, while some custom M functions or adding an index column can break folding.
30
Your measure using IF and many nested CALCULATE calls is slow. How do you optimise it?
I would store repeated sub-expressions in variables so they are computed once, replace nested IF chains with SWITCH(TRUE(), ...), use column filters instead of FILTER over tables, and avoid context transition inside large iterators. I would also check whether some logic can move into a calculated column or Power Query at refresh time. DAX Studio timings confirm whether formula engine time drops.
Tips to crack the LTIMindtree Power BI interview
Practise aptitude, logical reasoning and basic coding questions, as the online assessment is usually the first filter.
Revise SQL, OOP and testing fundamentals, plus any cloud or data tools you list on your resume.
Learn about the L&T Group background and the LTI and Mindtree merger to answer company-related questions.
Keep a one-minute story ready for every project on your CV: problem, your part, tools, result.
Practise the hard questions on this page aloud; LTIMindtree interviewers usually ask follow-ups on your first answer.
Frequently asked questions
How many rounds are there in the LTIMindtree Power BI interview?
Candidates usually go through 4 stages: Online assessment (aptitude + reasoning); Coding test; Technical interview; HR round. The exact rounds change with the role, team, location and your experience, so confirm the process with the recruiter.
Which topics should I prepare for the LTIMindtree Power BI interview?
This practice set leans on Visualisation and Report Design (7), DAX Fundamentals (6), Power BI Fundamentals (6), Power Query and Data Transformation (4). Revise those first, then practise explaining one or two of your own projects end to end, because most LTIMindtree interviewers ask you to walk through real work.
Are these the exact questions asked at LTIMindtree?
No. These are curated practice questions that match the skills and difficulty usually tested in it services interviews like LTIMindtree's. They are not a leaked or verified list of past questions.
Where does LTIMindtree hire Power BI professionals in India?
LTIMindtree has large teams in Mumbai, Pune, Bengaluru, Chennai, Hyderabad. Openings and locations change often, so check the LTIMindtree careers page and filter by city and experience.