<![CDATA[Interview ML: Resources]]>https://interviewml.substack.com/s/resourceshttps://substackcdn.com/image/fetch/$s_!nohV!,w_256,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc0aa431e-84b4-4de5-97eb-42044587dfa3_183x183.pngInterview ML: Resourceshttps://interviewml.substack.com/s/resourcesSubstackSun, 10 May 2026 04:04:59 GMT<![CDATA[Question - Creating a Quick Data Pipeline]]>https://interviewml.substack.com/p/creating-a-quick-data-pipelinehttps://interviewml.substack.com/p/creating-a-quick-data-pipelineSat, 15 Apr 2023 16:30:32 GMTHi, 

Suppose you're given the following dataframe:

Using this data, write a data processing pipeline to perform the following actions to the data:

  • Groups the dataframe by a specified column and returns the mean age of the group

  • Converts the column name to uppercase

If you're using Python, you can build the dataframe using the below code:

— Answer for the previous article:

with helper as (select candidate_id from candidates where lower(skill) in ('python','tableau','postgresql'))

select candidate_id from helper group by candidate_id having count(*)>=3 order by candidate_id

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]]><![CDATA[Question - Data Science Skills (SQL) - Easy]]>https://interviewml.substack.com/p/data-science-skills-sql-easyhttps://interviewml.substack.com/p/data-science-skills-sql-easySun, 26 Mar 2023 14:51:17 GMTGiven a table of candidates and their skills, you're tasked with finding the candidates best suited for an open Data Science job. You want to find candidates who are proficient in Python, Tableau, and PostgreSQL.

Write a query to list the candidates who possess all of the required skills for the job. Sort the output by candidate ID in ascending order.

Assumption:

  • There are no duplicates in the candidates table.

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Answer: 

with helper as (select candidate_id from candidates where lower(skill) in ('python','tableau','postgresql'))

select candidate_id from helper group by candidate_id having count(*)>=3 order by candidate_id
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