Question: 1 Have you ever taken part in improving a company’s existing data architecture?
Please describe your involvement in the process and the overall impact the changes had on the company.
How to Answer
Routine tasks and maintenance are an important part of a data architect’s job. However, as a data architect, you should also be proactive and strive to improve the company’s data processes and structures. Employers want to hire data architects with a critical mindset who are willing to take part in increasing the efficiency and productivity of current environments. So, do your best to show the interviewer you don’t get preoccupied with routine tasks, and you don’t lose sight of the bigger picture.
“In my work experience, marrying external data with internal data in corporate systems can pose a variety of threats to data integrity. That’s why I launched a project where I established a step-by-step screening process for our 3-rd party purchased data. I also managed to further improve the relationship with our data supplier, who, in turn, agreed to run a few checks on their data before sending it to us. This initiative had a positive impact on the company’s data reliability and decreased database errors by 29% within 1 year.”
Question: 2 As a data architect, have you faced any challenges related to the company’s data security?
How did you ensure the integrity of the data was not compromised?
How to Answer
Data security is a top priority for every company. That’s why hiring managers would like to learn more about your experience with data security issues. When answering this question, emphasize that data security is an important aspect of your job, although your background isn’t focused in that particular field.
“When working in a team, it’s sometimes hard to agree on what could pose a security risk. I remember a situation when some colleagues of mine wanted to change the established process for uploading franchise data to our system. I was sure theses changes could result in security risks. So, in order to validate my point, I calculated the possible financial loss to the company in case security was compromised. This prompted the team members to modify their plan to strengthen data security measures.”
Question: 3 As a data architect, you should be up to date with the latest technologies and developments in the field.
How do you keep yourself informed about the new trends in data architecture?
How to Answer
When working in a technical role, it’s common to get absorbed in the company’s current processes and miss out on the latest industry developments. Hiring managers will value your willingness to educate yourself despite your busy schedule. So, try to list news resources you’re subscribed to, and mention some conferences or trainings, or industry events you attend when you have the chance.
“I do my best to stay informed about the latest industry trends and technology advancements. I believe this helps me learn things that can improve my work… Or inspire me to come up with an idea that will benefit the company’s status quo. I’m subscribed to newsfeeds such as InformationWeek and TechNewsWorld. I also attend 2-3 conferences a year where I network with other professionals in the field. Whenever my schedule allows it, I attend specialized trainings and seminars.
Question: 4 What is referential integrity?
Referential integrity is a subset of data integrity that refers to the accuracy and consistency of data linked between tables. Referential integrity is majorly important -if a database lacks referential integrity, this can result in return of incomplete data without any indication of an error.
For instance, we can say the foreign key in a certain child table maintains the referential integrity within the database by referencing a valid, existing primary key in the parent table.
A foreign key in SQL is defined through a foreign key constraint. This type of constraint verifies that the values in the child and parent tables match. Therefore, referential integrity doesn’t allow us to add records to a related table unless there is an associated record in the primary table. It also prevents us from changing values in a primary table that would lead to orphaned records in a related table. Moreover, it makes it impossible to delete records from a primary table in case there are matching related records.
To visualize how the fields from the various tables within a database refer to each other, people usually use Entity-Relationship diagrams (ER diagrams), or, the simpler and handier tool – relational schemas.
Question: 5 Provide me an example of a time when you had to teach someone a new skill?
This is an easy one, right? The Hiring Manager wants you to demonstrate that you are a person that is willing to teach others. The fact that you are willing to teach means a few very important things:
• You are willing to share knowledge (very valu able for the company)
• You’re a team player who is willing to help
• You relate well to people
The second aspect that is important about this question is the method that you used when you were teaching. How did you share your knowledge? Did you have to use some special technique in order to explain a given concept? Did you have a strategy that helped to facilitate learning? Perhaps you provided valid practical examples?
Here’s an example of such a situation:
You can say that you always wanted to teach your younger brother how to create good PowerPoint presentations. At first, it was difficult because it was very hard to get his attention. Then you proposed creating a presentation together – a presentation about his favorite motorbike company. He instantly agreed because it was something that he was interested in sharing with his friends and perhaps post in one of his favorite forums. At first, you were the one who was working with the mouse and the keyboard, but then you let him complete the second half of the presentation and you gave him your guidance throughout the process. The results were amazing your brother learned so much in such a short period of time. This was a very fulfilling experience for you and you realized that you enjoy teaching.
Question: 6 As a data architect, what steps have you taken to understand how different departments use the company’s stored data?
How to Answer
Different departments have different data needs. And, as a data architect, you must have the ability to work with people from non-technical backgrounds to understand how they use the available data. When you answer this question, do your best to convey that you’re willing to educate yourself to improve your job and better serve the company’s data requirements.
“As a data architect, understanding the work of my colleagues in different departments has always been important to me. In my previous workplace, I’d regularly meet with reps from other teams to discuss their current and future projects. I would ask a series of questions, instead of making assumptions. This approach has allowed me to correctly identify and plan their data needs.”
Question: 7 To effectively manage a company’s data infrastructure, it is important for a data architect to have an in-depth understanding of the business and its strategic challenges.
How have you approached this requirement in your past position?
How to Answer
Missing the bigger picture is a common problem for data architects, due to the technical nature of their work. With your answer, you have to reassure the hiring manager that you’re capable of taking proactive steps and stay on track with the overall business strategy and goals of the company.
“In my experience as a data architect, I’ve learned that in order to improve my performance, I have to be constantly aware of the company’s short-term and long-term goals. This is why I’ve been proactive in my communication with management and c-level executives. I’ve also attended corporate trainings on a regular basis. This has given me a chance to ask the right questions to the right people.”
Question: 8 What is/(are) your greatest strength/(s)?
A question that leaves a much more pleasant flavor than “What is your biggest weakness?” Nevertheless, you need to prepare to answer it, because it is an important one and it comes up at almost all HR interviews.
Think of the role you are applying for. What are the greatest strengths that someone who wants to be successful in this position must have? Let’s say that you are interviewing for the position of Project Manager.
A Project Manager needs to be a great:
• Team player
• Problem Solver
If the interviewer asks you for your greatest strength (singular) pick one of these qualities. The one that is, in fact, your greatest strength, so make sure that you have a great story illustrating that you are really good at this skill. If you are asked to list multiple strengths, you can pick up to three of these qualities. Don’t list more than three strengths, as it will come off as though you are strong with everything, which will dilute the effect that you obtained in the first place.
Avoid vague words (such as maybe, probably, guess, usually) when you talk about your biggest strength/s.
Subject Specific Questions
Question: 1 A lot of companies use data from both internal and internal sources.
Have you faced any problems while trying to integrate a new external data source into the existing company’s infrastructures? How did you solve these problems?
How to Answer
External data often comes from sources using different data formats and systems. Obviously, that may cause a series of issues when importing this data into the company’s data systems. As a data architect, you have to make sure the data format is readable and ready-to-use, before storing it in the data warehouse. With this question, hiring managers want to assess your problem-solving skills when faced with external data integration challenges. So, try to provide an answer that will demonstrate how you address such issues.
“In my work experience, the cause for external data integration issues is usually a different system that creates the data in an incompatible format. Unfortunately, it isn’t possible for all companies to use the same systems. So, I solved this problem by creating and running a script prior to uploading the data in my company’s warehouse tables. The script not only changed the external data format but also ran tests to ensure the new format was compatible with our systems.”
Question: 2 Have you worked with open source technology? Tell us about some issues you have comes across when using it.
How to Answer
When an interviewer asks a specific question like that, the company is either considering using open source technology in the future or is already utilizing it. If you have relevant experience, give some particular examples. And be sure you also highlight your ability to modify the open-source programming code. If you haven’t encountered any problems using it, mention any possible disadvantages to open source technology you’re aware of.
“I’ve worked with both Hadoop and MySQL without facing any major problems. Nevertheless, I realize that using open source databases or software utilities has its drawbacks. For example, you have to rely on advice from user forums, as there is no formal customer support to address your issue. Another thing is that developers don’t spend a lot of time on their user interface, so you may lack the resources you need to get started.”
Question: 3 State and describe the different types of SQL joins.
How to Answer
The basic types of SQL joins are: inner, left, and right (in SQL theory, there is one more type of join – full. However, it is used very rarely today). The easiest and most intuitive way to explain the difference between the inner, left, and right joins is by using a Venn diagram, which shows all possible logical relations between data sets.
The INNER JOIN lets us select all records from Table A and Table B, as long as there is a match between the columns.
The SQL LEFT JOIN returns all records from the left table, plus the matched values from the right table. In case there are no matches, the left join still returns all rows from the left table and a NULL value from the right.
Regarding the functionality of the SQL RIGHT JOINS – it is identical to LEFT JOINS, but with the opposite direction of the operation.
Question: 4 What is a primary key and a foreign key?
How to Answer
A primary key is a column (or a set of columns) whose value exists and is unique for every record in a table. It’s important to know that each table can have one and only one primary key.
Therefore, you can think of a primary key as the field (or group of fields) that identifies the content of a table in a unique way. For this reason, the primary keys are also called the unique identifiers of a table.
Another crucial feature of primary keys is they cannot contain null values. This means, in an example with a single-column primary key, there must always be a value inserted in the rows under this column. You cannot leave it blank.
One last remark about primary keys – not all tables you work with will have a primary key, although almost all tables in any database will have a single-column or a multi-column primary key.
A foreign key, instead, is a column (or a set of columns) that references a column (most often the primary key) of another table. Foreign keys can be called identifiers, too, but they identify the relationships between tables, not the tables themselves.
In the relational schemas form of representation, relations between tables are expressed in the following way – the column name that designates the logical match is a foreign key in one table, and it is connected with a corresponding column from another table. Often, the relationship goes from a foreign key to a primary key, but in more advanced circumstances, this will not be the case. To catch the relations on which a database is built, we should always look for the foreign keys, as they show us where the relations are.
Question: 5 How many types of data structures does R have?
How to Answer
This question is important because virtually everything you do in R involves data in some shape or form. The most commonly used data structures in R are these:
• Vectors (atomic and lists);
• Data frames;
Question: 6 What modeling tools have you used in your work so far? Which do you consider efficient or powerful?
How to Answer
Even if data modeling isn’t one of your main responsibilities, your role as a data architect requires you to have an in-depth understanding of data modeling. If you lack the experience, demonstrate that you are well-informed on the topic and mention the data modeling tools you find most useful. The interviewer will value that you’re at least familiar with the subject.
“I’ve used mainly both Oracle SQL Developer Data Modeler, and PowerDesigner. I can say that the Oracle Data Modeler has been more than sufficient for my needs with its dimensional modeling, and integrated source code control that supports collaborative development. However, PowerDesigner also boasts some wonderful technology-centric metadata management capabilities for data architects, and business-centric techniques for non-technical coworkers. Overall, I think both tools are worth the try, depending on the company’s needs.”
Question: 7 What’s your experience with batch and real-time data processing?
How to Answer
Each of these data processing methods can be applied depending on the business case. If you have experience with only one of them, provide examples of situations where the other processing method would be a better fir. This will indicate you have a basic understanding of both batch and real-time data processing.
‘I’m familiar with both types of data processing. However, I’ve had more exposure to batch processing. That’s because one of my responsibilities was to write programs that captured, processed, and produced output for the company’s billing department. As I mentioned, I’ve had less experience with real-time data processing. However, I know our company uses it to take immediate action on the data collected from our stores’ POS systems.”
Question: 8 In your role as a data architect, what metrics have you created or used to measure the quality of new and existing data?
How to Answer
Having established processes to ensure the quality of data is key to a company’s data infrastructure. With this question, the hiring manager wants to assess your relevant experience. Make sure you highlight the particular dimensions you’ve monitored to validate the data quality.
“I’ve always been involved in ensuring data quality in my job as a data architect. My team and I monitored some specific dimensions to validate the quality of data. These included completeness, uniqueness, timeliness, validity, accuracy, and consistency. Monitoring these dimensions helped us detect inconsistencies that could negatively affect the accuracy of data analysis.”
Question: 9 Tell us about a situation when you made changes to a company’s data management systems and the impact it made on the company.
The data needs of companies change and hiring managers want to make sure they hire an architect that will not only adapt to the new requirements but will also take up the initiative to implement these changes and introduce some new improvements. If you are just beginning your career as a Data Architect and you don’t have experience in dealing with such changes, think of a hypothetical situation that will demonstrate your problem-solving skills and hands-on approach to challenges.
Here’s an example of such a situation.
While working for my previous employer, I was part of a project aiming to make data more accessible to all company employees. Each department’s data was siloed and team members in other departments couldn’t access it. Acquiring data outside one’s own department was a dull and tiresome process that prevented timely analyses. I actively took part in making data sharing among the company’s departments easy without compromising data security. Thus, analysts were able to complete their projects in time using a much more robust dataset than before. This made it possible for senior management to make fast and better-informed strategic decisions.
Question: 10 What issues have you faced while leading teams tasked with data/database strategy development?
Tell us how you solved these issues.
How to Answer
You can approach this question in a more general way, or describe a real situation you and your team have faced when working on a specific task. Either way, make sure you point out your problem-solving skills and the ability to work in a team to reach a common goal.
“In my experience as a data architect, I’ve often worked with teams to develop changes in the data architecture of our company. Of course, people on a team come from different backgrounds and have varying opinions that affect their priorities. What I’ve discovered is that making compromises is crucial to the success of the task, along with staying open-minded to others’ ideas. That said, once we’ve identified our common goals, a consensus has always been easy to reach.”
Question: 1 What challenges have you faced working with colleagues with no technical background?
How did you address and overcome these challenges?
How to Answer
Data architects often work with other departments within a company. That involves collaborating with people who lack technical background and understanding of the data processes. The interviewer would like to assess your communication style and your ability to reach common ground with your coworkers, in spite of your differences. Describe a specific situation to illustrate the issues you encountered and how you solved them.
“I believe a good data architect should understand the needs of the different departments across the company. That said, I’ve had to work with people who don’t fully understand my role and responsibilities on numerous occasions. Some of my coworkers would pose requests that I had to reject due to our data architecture limitations. And that has lead to certain tensions. I’d say overcoming such challenges takes time. Gradually, we learned more about each other’s work which helped us brainstorm possible solutions. All in all, making the extra step to educate myself and the others made has made all the difference.”
Question: 2 How would you describe your work style?
How to Answer
This question is not so much about your personality, but more about how you approach your work to get things done. Talk about the way you handle tasks and projects, and how you communicate with coworkers and clients. Your work style might be: collaborative, well-structured, speedy, flexible, or independent. No matter what word you choose to describe it, keep the job description in mind and how your work style fits the profile.
“I’d describe my work style as collaborative. I like to work on full-team participation projects and co-create with my teammates. If I’m not sure of the direction I should take on a project, I always consult with my team. This way we can work toward consensus and align our ideas.”
Question: 3 How would you resolve a conflict within your team?
How to Answer
The hiring manager wants to hear about your ability to professionally solve team issues when they occur. Think of an example where you had to use your communication skills to handle a conflict with your coworkers. Or when you managed to help 2 of your teammates find common ground as a mediator.
“I like to think I have excellent conflict management skills. As a data architect in a large company, I’ve worked in a high-stress environment. And that has sometimes caused tension to build up among team members. When this escalates to a conflict, I try to deal with it openly. Usually, I’d organize a group meeting where everyone can voice their concerns. This is how we can sort out the issue and move on with our work on the project.”
Question: 4 What is the most critical factor for you when taking a job?
How to Answer
There are a lot of factors that may influence your decision to take on a new job. These include:
- career growth opportunity;
- work/life balance;
- travel required for the role;
- medical and health benefits;
- perks such as a gym membership, onsite kids center, spending account;
- paid vacation time;
- the company’s location;
- the company’s reputation and culture.
Share with the interviewer which factors are most important to you when you consider starting a new job. If you aren’t sure about all the details regarding this position, this is a good time to get informed.
“The most important factors for me, as a data architect, are the company’s industry and the workplace culture. The first one predefines the projects I’ll be involved in. The second one indicates if the work environment will be positive and teamwork-oriented. To me, those are equally important to compensation and benefits.”
Question: 5 Are you also interviewing with any of our close competitors?
How to Answer
If the interviewer wants to know if you’re also applying for a job at a competitor’s company, you can give a direct answer. However, you should refrain from giving away the name of the company or sharing too many details. Let the interviewer know you aren’t putting all of your eggs in one basket. At the same time, try to leave the impression that you are critical when it comes to the companies you apply at.
“I wouldn’t disclose the names of the competitors I’m currently interviewing with. However, I can tell you that I’m in the mid-interview stages with 3 other companies. That said, your company is my first choice and I’m happy that we’ve reached the final stage in the process.”
Question: 6 How would you assess your performance in the interview so far?
How to Answer
This is a question you should answer openly. Generally, you would know if you performed well, or if your interview were a disaster. In fact, if you address the issues of your performance, you might get a chance to answer some additional questions that could give you extra points.”
If you think that your performance in the interview is going great:
“I’m positive that the interview has been quite successful and I’m satisfied with my performance. Is there anything you’d like me to clarify from our talk?”
If you think that your performance in the interview is not satisfactory:
“I don’t think I managed to portray myself in the best light possible in this interview. However, I’m always trying to do my best. So, if there’s anything I could further clarify for you, I’d be more than happy to do so.”
Question: 7 What would you do if a colleague was using a company phone for personal use?
These types of questions about the unethical behavior of one of your colleagues are difficult to answer. First of all, it is a very awkward situation. Most people don’t want to rat their co-workers but are not OK with unethical behavior neither. That means that they need to make a tough decision between two conflicting actions.
Depending on how serious and unethical the actions of your colleague are, you usually have two options:
• Talk with them before reporting to the
manager and try to convince them to change their behavior
• Report them directly to the manager
In this case, given that a personal phone call from a company phone is not something that endangers the company and its reputation in the long run, you might try to fix the issue yourself by talking to your colleague and explaining to him that using the company phone for private conversations is not allowed. Strengthen your argument by saying that if everybody started doing such things, the company would eventually go bankrupt. Furthermore, he is setting a wrong example for the rest of your colleagues. Given that the company trusted you with this job, you need to repay that with solid work and consistently ethical behavior. If the pattern continues even after you talked to your colleague, you should contact Management.
Had the question involved a more serious violation (sexual harassment, stealing, disclosure of confidential information, etc.) you need to demonstrate your readiness to report the issue directly to your supervisor.
Question: 8 How would you deal with a significant mistake at work?
The best way to deal with a mistake at work is to own up to it. Otherwise, it will haunt you and will probably transform into something that cannot be fixed. A timely reaction could prevent the damage deriving from your mistake and shows strength of character.
One of the worst things that can happen to you is to have a manager who has lost trust in your work.
Hiding mistakes can cause that. It will be much better to confront your manager immediately and admit that you made a mistake. Then, once he knows about the situation, he will be able to take appropriate action in order to resolve the situation. It is more likely that he will know how to address the issue because he is more experienced than you.
The more subtle aspect of this question is about how you learn from significant mistakes. Are you going to remember that mistake and learn from it in the future? Are you going to do everything possible in order to avoid it in the future? What type of precautionary measures would you take? Everybody makes mistakes, yes. The important thing is that you show that you are determined to learn from yours.
Question: 9 What would you do if one of your colleagues was not performing well?
Open communication is the best way to address problems when you are working with people. Remember that. By openly sharing your concerns with your colleague and hearing his opinion, you will make sure that both of you are on the same page about the current situation. You need to fully understand what caused his weak performance.
It could be due to:
• Misunderstanding of his tasks
• Lack of experience in handling this type of tasks
• Personal problems
• Anxiousness to do too much
Then, once you have figured out what the problem is, the next step is to figure out a way to resolve the issue.
For example, you can propose the following solutions:
• Misunderstanding of his tasks – Go through his tasks together and tackle any problematic areas
• Lack of experience in handling this type of task – Depending on the knowledge gap and the deadline that you have you can i) propose to go through the unfamiliar topics together ii) propose to change his assignment with something that he is familiar with and where he can excel
• Personal problems – Offer flexible hours or suggest that he asks the manager for help and explain his personal situation; say that you are behind him and that everyone has difficulties at some point
• Anxiousness to do too much – Explain that the best employees are great at doing well the small things; assure him that he needs to focus on doing well his ordinary tasks without being distracted by issues that are outside of his current capabilities.
Brainteasers: Scenario Based QnA
Question: 1 What is the sum of the numbers from 1 to 100?
There’s a little bit of history coming with this question. The math teacher of young Karl Gauss, the famous mathematician, asked the entire class to sum the numbers from 1 to 100. He expected that the task would require at least half an hour to his students, but was shocked when Gauss gave him the exact number within mere seconds. Anyway, here is how this question is solved. There are precisely 50 pairs of numbers from 1 to 100, whose sum is 101.
1 + 100 = 101, 2 + 99 = 101, 3 + 98 =101, etc. 50 * 101 = 5050 This trick will work for any series of numbers provided that they are evenly spaced. You need to find the sum of the first and the last number and then multiply by the number of pairs.
Question: 2 You are given two containers one is 5 and the other one is 7 gallons. How do you use them to measure 4 gallons of water?
Fill the entire 7 gallon container with water. Then use the water in the 7 gallon container in order to fill the entire 5 gallon container. This would leave 2 gallons of water in the 7 gallon container. Dump the water in the 5 gallon container and then pour in it the 2 gallons of water that are in the 7 gallon container. Fill the entire 7 gallon container with water and then start pouring the water in the 5 gallon container. Given that it is already filled with 2 gallons of water, you will be able to pour only 3 gallons, which means that 4 gallons would remain within the 7 gallon container. This is how you are able to measure 4 gallons of water.