Recent Data Analyst Interview Questions

Bradley E. - "Here's a simpler solution: select u.username , count(p.postid) as countposts from posts as p join users as u on p.userid = u.userid where p.likes >= 100 group by 1 order by 2 desc, 1 asc limit 3 `"See full answer

Christian B. - "with cte as (select ts.employee_id, e.name, t.id as test_id, max(distinct ts.score) as total from test_results as ts join tests as t on ts.test_id = t.id join employees as e on ts.employee_id = e.id group by ts.employee_id, e.name, t.id) select employee_id, name as employee_name, sum(total) as total_score from cte group by employee_id, employee_name order by total_score desc, employee_id asc ;"See full answer

Rishabh L. - "with empbysalary as ( select id, firstname, lastname, salary, department_id, rank() over (partition by department_id order by salary desc) as rnk from employees ) select d.name as department_name, e.id as employee_id, e.firstname, e.lastname, e.salary from empbysalary e join departments d on e.department_id=d.id where e.rnk=1 order by 1; `"See full answer

Kavi S. - "SELECT id, first_name, last_name, salary FROM employees ORDER BY salary DESC LIMIT 3 `"See full answer

Daniel C. - "select name, stock from products p left join transactions t on p.id = t.product_id order by date desc limit 1"See full answer

Victor N. - "--country names are UPPERCASE but the table in the in the question showing lowercase. That's why it took me a while to figure it out until I ran the country column WITH RECURSIVE Hierarchy AS ( SELECT e.Emp_ID, CONCAT(e.FirstName, ' ', e.MiddleName, ' ', e.LastName) AS FullName, e.Manager_ID, 0 AS Level, CASE WHEN e.Country = 'IRELAND' THEN s.Salary * 1.09 WHEN e.Country = 'INDIA' THEN s.Salary * 0.012 ELSE s.Salary "See full answer

Niranjan M. - "Interesting question. Let's take a step back and focus on the WHAT and WHY of Google Flights. The narrative for Google Flights as a product or platform imo is: As a platform, I wish to make flight information available, so that users can make knowledgable decisions based on their travel needs. So essentially, it helps users by providing information, so that they can make optimized decisions. In order to determine if Google should introduce ads, we should consider the impact on both val"See full answer

Yashasvi V. - "WITH RECURSIVE fibonacci_series AS ( SELECT 1 AS n, 0 AS fib1, 1 AS fib2 UNION ALL SELECT n + 1 AS n, fib2 AS fib1, fib1 + fib2 AS fib2 FROM fibonacci_series WHERE n < 20 -- Limit the series to 20 numbers ) SELECT n, fib1 AS fib FROM fibonacci_series ORDER BY n; `"See full answer

Erjan G. - "1) select avg(session) from table where session> 180 2) select round(sessiontime/300)*300 as sessionbin, count() as sessioncount from table group by round(sessiontime/300)300 order by session_bin 3) SELECT t1.country AS country_a, t2.country AS country_b FROM ( SELECT country, COUNT(*) AS session_count FROM yourtablename GROUP BY country ) AS t1 JOIN ( SELECT country, COUNT(*) AS session_count FROM yourtablename `GROUP BY countr"See full answer

Ali H. - "SQL databases are relational, NoSQL databases are non-relational. SQL databases use structured query language and have a predefined schema. NoSQL databases have dynamic schemas for unstructured data. SQL databases are vertically scalable, while NoSQL databases are horizontally scalable."See full answer

Aaron W. - "Clarification questions What is the purpose of connecting the DB? Do we expect high-volumes of traffic to hit the DB Do we have scalability or reliability concerns? Format Code -> DB Code -> Cache -> DB API -> Cache -> DB - APIs are built for a purpose and have a specified protocol (GET, POST, DELETE) to speak to the DB. APIs can also use a contract to retrieve information from a DB much faster than code. Load balanced APIs -> Cache -> DB **Aut"See full answer

Anonymous Eagle - "I generate insights through stakeholder requirements and the data I have in hand"See full answer

Kofi N. - "const mergeIntervals = (intervals) => { const compare = (a, b) => { if(a[0] b[0]) return 1 else if(a[0] === b[0]) { return a[1] - b[1] } } let current = [] const result = [] const sorted = intervals.sort(compare) for(let i = 0; i = b[0]) current[1] = b[1] els"See full answer

M D. - "Understand the business problem: Identify the business problem that the AI data product is intended to solve. Identify the target audience: Understand who will be using the data and what problem they will be solving for using the data. This will inform the features and functionality that should be included in the product. Gather and preprocess the data: Collect and preprocess the data that is relevant to the problem that it is being solved for. This will inform the AI algorithm"See full answer

Mark - "Questions: Should we consider US or Global? Is there any existing market insights/research around driverless cars adoption? Can we assume that driverless car technology is production / public ready by 2025? Is this focus on commercial or consumer use? Assumption: Let's look at US to start for our estimation since Driverless car regulation and adoption trend will probably differ per country Let's also assume we want to estimate market size for driverless cars in 2025 for consume"See full answer

Priyanka D. - "Target Consumers: corporate clients - for business meetings students (in school, college) aspirants who want to take competitive exams/tests Identify underserved customer needs: re-application leads to post-it's not being sticky enough space crunch so user needs to be precise post-its need to stick from all 4 corners for it to be readable and so it folds less writing with pen, marker gets imprinted on next page Define Value Proposition: a small piece of paper with concise list of"See full answer

Shreya S. - "Firstly, I would like to be in a room with all the stakeholders (tech/business) and the decision makers. Now starts the analysis of the situation. Certain questions that I will be looking for an answer are- Is this a new issue? or an old one? What is the severity and priority of the feature in the release? In terms of business values. How long would it take the engineering team to fix the issue? Can we manage for a workaround meanwhile the issue gets fixed? What are the risks inv"See full answer

Sreenisha S. - "Let me tell you about a time where a website I managed suddenly showed slow performance and the mistake on our side was it was unnoticed until a user reported the issue to management. As a PM for that project, I took full responsibility of the situation and worked with the engineering team to quickly resolve it. This mistake taught me the importance of focusing and monitoring non functional requirements as well in addition to new feature development /adoption where I was mostly spending my time"See full answer

Ashley C. - "I follow a variation of the RICE framework when prioritizing how I ship product features. I start by looking at: Reach: Because the customer segmentation across our product portfolio is so similar, I tend to hold a lot of weight on product features that will maximize our customer reach with a minimal LOE. Impact: After establishing which customer segments will benefit from the product feature, I determine the urgency and estimated impact on each customer segment based on customer i"See full answer