25 Data Analyst Interview Questions and Answers to Prepare for in 2021
Data has become the buzzword in the world of technology today. With the volume of data increasing several folds, it has become quite challenging for different industries across sectors to manage and use them effectively. This sudden importance of data has led to massive hiring across the globe, and enterprises are looking for people who can do the number crunching and make sense out of it. Nowadays, various large, mid, and small-cap companies are hiring data analysts at all levels of experience who can help their industries to grow in the right direction.
With this massive hiring in the field of data, it is of utmost importance to know and understand the skills that top recruiters across the globe are looking for when hiring data analysts. Learning and mastering the data analytics skills and knowing the kind of interview questions you will get asked in a data analyst job interview is the way forward to succeed in an analytics job interview.
The data analytics job interview questions and answers are divided based on critical skills that are a must for any data analyst job. It covers data analyst interview questions for each of those five skills that can help you crack a data analyst role at one of the FANG companies. Data analysts require a blend of Business and Communication Skills, Analytical Skills, Critical Thinking, Technical Skills, and Data Visualization Skills. From a broad spectrum, anyone who can leverage these skills can be a good fit for data analyst jobs at top tech companies across various industries from a broad spectrum.
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Data Analyst Interview Questions and Answers on Business and Communication Skills
Q1. What are the key steps to solve a business problem through data?
This is one of the important interview questions for a data analyst. The key steps to solve a business problem through data are:-
- Gathering and Understanding the Problem Statement
- Collecting data and ensuring that all the important variables are present
- Understanding the as-is process on which the reports run, if any
- Doing Exploratory Data Analysis and data value exploration
- Preparing prototypes of the new service
- Building data models on Business Intelligence tools or data warehouses
- Creating dashboards on the data model and preparing visualizations
- The last step is to generate insights for the business and give them direction to make correct decisions
Q2. How important is it to understand what the business does before analyzing its data? Explain with a situation, or example
It is vital to understand the domain in which the business model for an organization runs. Without understanding the key elements of the business, it is impossible to run data models and gather insights from the same. For example, for a data analyst who is unaware of how a marketing campaign runs and what different strategies are used in marketing, it will be pretty challenging for them to crunch numbers and generate business insights.
Q3. What should you keep in mind before presenting your results to the management?
The things to keep in mind before presenting statistical results to the management are:-
- Ensure you understand the critical elements of the business model
- Know your management and their requirements in and out
- Present your results in such a way that is easily understandable by the audience
- Ensure you have to the point conclusion or inference for each of your findings
- Be open to constructive feedback
Q4. List down some of the challenges that a data analyst might encounter that can impede their ability to leverage analytics.
Following are the problems that a data analyst might encounter while solving a problem:-
- Lack of relevant size of the data to draw inferences
- Lack of domain knowledge or the business model
- Insufficient data variables in a given dataset
Q5. What are the common questions you would ask your stakeholder before working on dashboards?
The common questions to ask your stakeholder before working on a dashboard are:-
- What level of people will have access to the dashboard?
- What kind of dashboard are you looking for? Should it be analytical or operational in nature?
- What kind of productive decisions are you looking to make with the dashboard?
Data Analyst Interview Questions and Answers on Analytical Skills
Q1. What is the key difference between profiling of data and mining of data?
Data Mining is a process of analyzing large volumes of data and coming up with patterns from the same. This in turn helps in drawing insights and helps businesses with profitable decision making. Data Profiling is a process of profiling data or creating subsets of a larger data set based on certain conditions. This metadata is then analyzed and inferences are drawn for the same.
Q2. How should a data analyst validate a dataset for a given business problem?
You can validate a dataset by looking at its volume. One should also check if the given problem statement can be answered with the as-is information given by the management.
Q3. List down the steps that you would perform to clean your data.
This question is often a part of google data analyst interview questions. Data cleansing is one of the most important steps for a data analyst. Steps to perform data cleansing for a dataset are:-
- Checking for null values and treating them as needed
- Checking for duplicate values
- Checking for outliers and checking their significance in the stated business problem
- Removing unwanted columns
Q4. How important is it to retrain or re-look at your analysis or model?
It is very important to retrain or re-look at the analysis of model building. The reason for this is that with time, the volume of data increases. With the increase in volume, the assumptions made initially for the analysis might not hold true. Also, the data cleansing process will have to be done again to ensure that all-important pieces of data are integrated into the new analysis.
Q5. How do you identify outliers in a dataset?
Detecting outliers in a dataset is a key data cleansing and understanding processes for a data analyst. To identify outliers, one can use the following techniques:
- Box plot- One can plot box plots on any business intelligence tool to understand the variation in data provided.
- Z-score- One can also use a z-score to understand how many standard deviations above or below is an observation is from its mean
Data Analyst Interview Questions and Answers on Critical Thinking
Q1. Explain with an example of how you would use sensitivity analysis for decision-making
Sensitivity analysis is like a what-if analysis where an end-user can see a change in one dimension has an impact on other dimension with an increase or decrease by some percentage. An example of such a situation would be to see the difference in a business’s total revenues if the profit margin was increased or decreased by some x percentage.
Q2. How will you start designing a data-driven model for any given business problem? What will be your major focus points when designing the solution?
To design a data-driven model for a business problem, a data analyst will start understanding the company’s business model first. Once that is done, the problem statement and the end expectations have to be cleared. After these two steps, a data analyst will look into the data and point out any missing information. After the data collection process,data analyst will start modeling the data and creating dashboards.
Q3. How can you justify whether a model developed is good or not?
A model developed is good or not can be judged with the accuracy of the results. This accuracy should remain intact even when the volume of the data is increased. If a model can adjust to changes in the data smoothly, it can be said that the model developed is good.
Q4. How important do you think is the optimization of code in deploying your product?
Once a dashboard is finalized, a data analyst should ensure that the queries or scripts written for it are optimized. This optimization will help in a smoother user experience. Also, this optimization will aid in managing the data easily.
Q5. Explain the necessity of version control in a data analytics project
Version Control is of utmost importance in any project and the same goes with a data analytics project. Version Control helps by not losing out on the changes made. Also, in an agile way of working, one can easily refer to multiple versions and restore the changes based on business needs.
Data Analyst Interview Questions and Answers on Technical Skills
Q1. What are the various methods to remove outliers in a dataset?
Outliers can be removed in the following ways:-
- Giving the option to filter out the data
- Based on the distribution of data, replacing the outliers with mean, median, and mode
- Treating them based on post-test analysis
Q2. What are foreign key constraints in a data warehouse?
This is a part of basic SQL data analyst interview questions and answers asked in an interview. Using foreign key constraints is very important and a good practice while working on databases and using data warehouse. A foreign key constraint helps in understanding that the key only contains values that are in the primary key. This helps in data security and as well as joining of proper data.
Q3. How can you create a heat map in excel?
It is a one of the common excel interview questions for data analyst. The same answer applies to a google spreadsheet as well. Heat maps in excel can be created using conditional formatting option. One can customize the heat map based on basic statistics as well.
Q4. Explain how a map function works while using python for data analysis
It is a one of the common python interview questions for data analyst. Map() Function is a very important function and is widely used by developers. This function returns an object which is an iterator after using it on items like list and tuples.
Q5. While using Python, what Object Relational Mapping have you used?
The most used Object Relational Mapping is SQLAlchemy. It is a widely used library that acts as a bridge between Python programs and databases. It also helps in converting function calls into SQL queries.
Data Analyst Interview Questions and Answers on Data Visualization Skills
Q1. How important is it to choose the correct chart type to show particular data?
It is extremely important to choose the correct chart type while visualizing a particular dimension or measure. This ensures that the data is being seen in the most inferential way.
Q2. How would you enable your client to do what-if analysis in your dashboard?
In Business Intelligence tools a client can be enabled to do what-if analysis by using a feature of using parameters. These parameters can then be used in a calculation to showcase how the data is changing.
Q3. Throw some light on how crucial is report designing for a data analyst
As a data analyst, it is very essential to have the correct design of a dashboard that one is creating. The dashboard should be created based on best practices and should be simple to use. It should also answer all the questions for which the business is seeking answers to.
Q4. Which chart type is preferred for forecasting analysis and why?
For forecasting analysis, Trend lines are used to showcase the numbers. This is done because a line chart can easily show the upward and downward movement of any time related measure or dimension
Q5. Is it possible to visualize three dimensions in a single chart type?
Yes, it is possible to visualize three dimensions in a single chart type. This can be done by using pairwise scatter plot and adding colors for categorical dimensions.
This is not an exhaustive list of data analyst interview questions , however, these questions will give you an overview on the kind of questions you’ve to prepare for to land a data analyst role at any reputed company across the globe. Knowing the answers to these questions will definitely help you gain an overall understanding of your role and will also give the interviewer confidence in your skills and abilities as a data analyst.
