4 Lessons From My 4 Data Interviews

A couple weeks ago, I interviewed for four very different data positions. I have listed them below along with their respected industries:

• Business Intelligence Engineer (FAANG)

• Senior Data Engineer Consultant (IT Consulting)

• Entry Level Data Scientist (Banking)

• Data Analyst II (Healthcare)

Here’s what I learned..

Lesson 1: Know Your SQL!

While all positions were very different, there’s one thing that each interview had in common…SQL!

The importance of knowing SQL cannot be overstated. Not often will the starting point of your project be a simple .csv or Excel file. At the very least, you need to be able to query a database to retrieve the data you need and create your own dataset. Here are some of the SQL concepts I was tested on or asked about:

Joins

Know the differences between INNER, LEFT, and RIGHT joins. Know when you would use the INNER vs LEFT and vice versa. I was even asked about the CROSS JOIN.

GROUP BY & Aggregates

Understand how to aggregate your data and use GROUP BY. Practice use cases that would include MIN(), MAX(), AVG(), etc. These are helpful to create reports with metrics and KPIs so the end user can measure the performance of a business process.

Filtering With the WHERE Clause

Know how to build queries with not only one condition, but multiple conditions in the WHERE clause.

SQL Interview Problems Resources

I mainly used Stratascratch to practice SQL. Its by far my favorite site to practice SQL interview questions.

Lesson 2: You Won’t Be a Good Fit Everywhere

Understand that every interview is a two way street. You are interviewing the hiring team just as much as they are interviewing you. I had a rough interview for a position that I thought I really wanted, but after it was over I realized it was not a good fit.

Know what you value in a team and ask those questions. Here are some examples:

• What are some of the current pain points that your team is facing?

• What kind of work/projects would I be expected to do?

• How is the team positioned in the company? Is it considered as a strategic partner for key decision making?

• What is the work life balance like? How many hours does the team typically work in a week?

• What are things I can do in my first 90 days to make you not regret hiring me?

Lesson 3: Not Everyone Will See Your Worth

Know what you bring to the table and put a number on it. Be realistic, but also understand that not everyone will see you at that value.

That doesn't mean you are not worth it though! Be able to articulate your value well so you don't have to settle for less.

This can be tough for those of us who don’t like to talk about ourselves.

A great exercise a mentor did with me was to write down 3 things that I do very well. He then told me that when discussing my value, my answers should always highlight at least one of those 3 things. It changed my whole perspective.

If you think about it, the way you brand yourself in interviews and your resume can make a quite the difference in your salary. You need to take into account of the market, your skills, and your experience. And unfortunately, many of us downplay our experience and transferrable skills which can lead to us taking less than what we deserve.

Lesson 4: Network, Network, Network!

I was personally referred to 3 out of the 4 positions. I accepted an offer from 1 of the 3. Its no secret that it's who you know, not what you know. And you can get to know so many people by networking and building relationships. I can't stress this enough.

Are you in any data communities? I am biased, but my private discord community Data in Motion is a great example of the many data communities you can be involved in. I have had multiple referrals and job opportunities from connections I have made through data communities.

Another great way to network is through social media. LinkedIn is a great way to interact and form professional relationships. And the best part is that it does not take as much energy as in person networking in my opinion.

My Favorite TED Talk

I wanted to end this article with my favorite TED talk. This was given to me by a mentor at a previous job and it changed my whole perspective of networking.

All the best,

Kedeisha Bryan