Nick Singh | The Data Science Guy ๐Ÿ“• Profile picture
Author of Ace the Data Science Interview. Free Book Preview ๐Ÿ‘‡ https://t.co/1izgOFy1Kt Founder of https://t.co/yyE4B5Ltpf (SQL Interview Prep) Ex-Facebook
Mar 11 โ€ข 6 tweets โ€ข 3 min read
3 SQL Games that will take your SQL skills to the next level

๐Ÿงต๐Ÿ‘‡ 1. SQL Murder Mystery

A murder has happened in SQL city!

Can you use your SQL knowledge to find the killer?

mystery.knightlab.com
Image
Jan 10 โ€ข 5 tweets โ€ข 2 min read
โ€œcouldn't find an internship so I built an AI Robot Handโ€

Creating portfolio projects is an amazing way to stand out on the job hunt but I've never seen someone do a project as well as Alan Lu & his robot hand!

Want your portfolio project to stand out too?

Here's 3 tips ๐Ÿงต โœ… Align the project to your dream job

Want to work in robotics?

Do what Alan did!

Want to work in healthcare analytics?

Go on Kaggle, analyze a free CDC dataset, then visualize your results publicly on Tableau!

Want to be a PM?

Mock up & spec a new feature for Twitter!
Jan 8 โ€ข 4 tweets โ€ข 2 min read
Can you solve this real Microsoft SQL interview question:

โ€œWhich Azure customer buys at least 1 Azure product from each product category?โ€

You're given a customer_contracts table & a table of Azure products. Image Hints:

โ€ข Join the two tables with either a LEFT or INNER JOIN

โ€ข Count all of the distinct product categories that a customer has purchased a product from using COUNT(DISTINCT products.product_category) AS unique_count Image
Jan 2 โ€ข 5 tweets โ€ข 2 min read
Data Science Interviews cover a HUGE range of topics:

๐Ÿ”น Data Structures & Algorithms
๐Ÿ”น Product/Business Sense
๐Ÿ”น Machine Learning
๐Ÿ”น Statistics
๐Ÿ”น Python
๐Ÿ”น SQL

Seems like a lot?

IT F**KING IS !!

Here's why Data Science interviews seem to cover everything under the sun ๐Ÿงต๐Ÿ‘‡ In an ideal world, Data Science candidates are only evaluated on the skills needed for the job they will be doing.

But the reality is that many Hiring Managers don't know exactly what Data Science projects their team will work on next quarter, let alone next year.
Dec 28, 2023 โ€ข 12 tweets โ€ข 3 min read
8 must-read books to land a Product Data Science or Product Analytics job:

(along with a guided 12 week study plan)

๐Ÿงต๐Ÿ‘‡ Image First, refresh your statistics fundamentals by spending 2 weeks on OpenIntro Stats.

Don't skip this step, or you'll get wrecked by the A/B testing & ML concepts built on stats foundations

You can find a free version of the OpenIntro textbook here:
openintro.org/book/os/
Dec 25, 2023 โ€ข 6 tweets โ€ข 2 min read
Advanced SQL Interviews LOVE to test you on Window Functions.

Here's 4 real SQL interview questions from Uber, Google, Spotify & Wayfair to practice SQL window functions like:
โ€ข LEAD()
โ€ข LAG()
โ€ข RANK()
โ€ข DENSE_RANK()
โ€ข ROW_NUMBER()
โ€ข NTH_VALUE()

๐Ÿงต๐Ÿ‘‡ Image ๐”๐›๐ž๐ซ ๐’๐๐‹ ๐ˆ๐ง๐ญ๐ž๐ซ๐ฏ๐ข๐ž๐ฐ ๐๐ฎ๐ž๐ฌ๐ญ๐ข๐จ๐ง

Uses Row_Number() to find the 3rd ride booked:
datalemur.com/questions/sql-โ€ฆ
Dec 11, 2023 โ€ข 14 tweets โ€ข 3 min read
Google recently released an "Interview Warmup" tool, to help candidates who are applying to Data Analytics jobs at Google better prep for their technical interview.

Here's 15 Data Analytics Questions Google expects you to know:

(how many can you answer??) 1. Not all data or inputs for analysis arrive in perfect condition.

Explain some of the errors or problems you might look for as part of the data cleaning process.
Nov 30, 2023 โ€ข 13 tweets โ€ข 3 min read
My 22-year old coaching client landed a new-grad Machine Learning job at a NYC startup that pays $175k per year ๐ŸŽ‰

($120k base, $40k stock, $15k annual bonus)

Here's the 17 interview questions they were asked:

(how many of these could you answer?) ๐Œ๐š๐œ๐ก๐ข๐ง๐ž ๐‹๐ž๐š๐ซ๐ง๐ข๐ง๐  ๐Ÿค–

1. What is PCA, why is it helpful, and how does it work?

2. What is heteroskedasticity, and how can you check for it?

3. After loading the Boston house prices dataset (it comes with scikit-learn), can you find any outliers in the data?
Nov 21, 2023 โ€ข 13 tweets โ€ข 3 min read
My 22-year old coaching client landed a new-grad Machine Learning job at a NYC startup that pays $175k per year ๐ŸŽ‰

($120k base, $40k stock, $15k annual bonus)

Here's the 17 interview questions they were asked:

(how many of these could you answer?) ๐Œ๐š๐œ๐ก๐ข๐ง๐ž ๐‹๐ž๐š๐ซ๐ง๐ข๐ง๐  ๐Ÿค–

1. What is PCA, why is it helpful, and how does it work?

2. What is heteroskedasticity, and how can you check for it?

3. After loading the Boston house prices dataset (it comes with scikit-learn), can you find any outliers in the data?
Nov 20, 2023 โ€ข 5 tweets โ€ข 2 min read
Linear Algebra is FOUNDATIONAL to Data Science & Machine Learning.

Hereโ€™s 3 FREE Linear Algebra resources I highly recommend to build a strong foundation ๐Ÿงต๐Ÿ‘‡ ๐„๐ฌ๐ฌ๐ž๐ง๐œ๐ž ๐จ๐Ÿ ๐‹๐ข๐ง๐ž๐š๐ซ ๐€๐ฅ๐ ๐ž๐›๐ซ๐š ๐๐ฅ๐š๐ฒ๐ฅ๐ข๐ฌ๐ญ:

At only ~2.5 hours long, in the time it takes you to watch a movie you could instead develop some helpful intuitions about linear algebra!

youtube.com/playlist?list=โ€ฆ
Nov 16, 2023 โ€ข 5 tweets โ€ข 2 min read
Do you know SQL?

PROVE IT โ€“ try to solve this real Microsoft SQL Interview question with me ๐Ÿ‘‡ Image Write a SQL query to identify the top 2 Power Users who sent the highest number of messages on Microsoft Teams in August 2022.

Display the IDs of these 2 users along with total num of messages they sent.

Output the results in descending order based on number of messages. Image
Nov 14, 2023 โ€ข 4 tweets โ€ข 4 min read
Learn Data Science For FREE:

SQLโ†’
Python โ†’
Statistics โ†’
Machine Learning โ†’ sqlbolt.com
LearnPython.org
bit.ly/StatEssentials
bit.ly/CourseraMLCourโ€ฆ Practice Data Science For FREE:

SQL โ†’
Python โ†’
Statistics โ†’
Machine Learning โ†’ DataLemur.com
CodingBat.com/python
bit.ly/StatsInterviewโ€ฆ
Kaggle.com
Oct 27, 2023 โ€ข 5 tweets โ€ข 3 min read
REAL Spotify SQL Interview Question โ€“ can you solve it??

(SQL problem in next Tweet ๐Ÿ‘‡) Image Given three Spotify tables (artists,ย songs, andย global_song_rank)

Write a query to find the top 5 artists whose songs appear most frequently in the Top 10 of the global_song_rank table.

Display the top 5 artist names in ascending order, along with their rank. Image
Oct 26, 2023 โ€ข 7 tweets โ€ข 3 min read
Learn SQL in 30 days for FREE with these 5 amazing resources:

(be sure to bookmark this 30-Day SQL Roadmap)

A thread๐Ÿงต๐Ÿ‘‡ Image Week 1 ๐Ÿ—“๏ธ

Work through the first 12 free interactive lessons on SQL Bolt.

This will teach you
โ—‹ SELECT
โ—‹ WHERE
โ—‹ JOINS
โ—‹ Aggregate Functions

Don't worry about the Update/Create/Alter table lessons - skip these!

sqlbolt.com
Oct 2, 2023 โ€ข 6 tweets โ€ข 3 min read
3 SQL Games that will take your SQL skills to the next level

๐Ÿงต๐Ÿ‘‡ 1. SQL Murder Mystery

A murder has happened in SQL city!

Can you use your SQL knowledge to find the killer?

mystery.knightlab.com
Image
Sep 26, 2023 โ€ข 14 tweets โ€ข 3 min read
Google recently released an "Interview Warmup" tool, to help candidates who are applying to Data Analytics jobs at Google better prep for their technical interview.

Here's 15 Data Analytics Questions Google expects you to know:

(how many can you answer??) 1. Not all data or inputs for analysis arrive in perfect condition.

Explain some of the errors or problems you might look for as part of the data cleaning process.
Sep 20, 2023 โ€ข 11 tweets โ€ข 3 min read
A past coaching client of mine interviewed for an entry-level Data Science job in Los Angeles that paid $110k per year.

Here's the 19 interview questions they were asked:

(how many of these could you answer?) ๐’๐ญ๐š๐ญ๐ข๐ฌ๐ญ๐ข๐œ๐ฌ ๐Ÿ”ข

1. Explain the difference between population variance vs sample variance

2. Describe a p-value to a 13-year-old (8th grader)

3. What Does an R-Squared Value of 0.9 Mean?
Jul 29, 2023 โ€ข 6 tweets โ€ข 3 min read
3 SQL Games that will take your SQL skills to the next level

๐Ÿงต๐Ÿ‘‡ 1. SQL Murder Mystery

A murder has happened in SQL city!

Can you use your SQL knowledge to find the killer?

https://t.co/UHBZEOfdYgmystery.knightlab.com
Image
Jul 26, 2023 โ€ข 5 tweets โ€ข 2 min read
Linear Algebra is FOUNDATIONAL to Data Science & Machine Learning.

Hereโ€™s 3 FREE Linear Algebra resources I highly recommend to build a strong foundation ๐Ÿงต๐Ÿ‘‡ ๐„๐ฌ๐ฌ๐ž๐ง๐œ๐ž ๐จ๐Ÿ ๐‹๐ข๐ง๐ž๐š๐ซ ๐€๐ฅ๐ ๐ž๐›๐ซ๐š ๐๐ฅ๐š๐ฒ๐ฅ๐ข๐ฌ๐ญ:

At only ~2.5 hours long, in the time it takes you to watch a movie you could instead develop some helpful intuitions about linear algebra!

youtube.com/playlist?list=โ€ฆ
Jul 15, 2023 โ€ข 13 tweets โ€ข 3 min read
My 22-year old coaching client landed a new-grad Machine Learning job at a NYC startup that pays $175k per year ๐ŸŽ‰

($120k base, $40k stock, $15k annual bonus)

Here's the 17 interview questions they were asked:

(how many of these could you answer?) ๐Œ๐š๐œ๐ก๐ข๐ง๐ž ๐‹๐ž๐š๐ซ๐ง๐ข๐ง๐  ๐Ÿค–

1. What is PCA, why is it helpful, and how does it work?

2. What is heteroskedasticity, and how can you check for it?

3. After loading the Boston house prices dataset (it comes with scikit-learn), can you find any outliers in the data?
Jul 12, 2023 โ€ข 11 tweets โ€ข 3 min read
A past coaching client of mine interviewed for an entry-level Data Science job in Los Angeles that paid $110k per year.

Here's the 19 interview questions they were asked:

(how many of these could you answer?) ๐’๐ญ๐š๐ญ๐ข๐ฌ๐ญ๐ข๐œ๐ฌ ๐Ÿ”ข

1. Explain the difference between population variance vs sample variance

2. Describe a p-value to a 13-year-old (8th grader)

3. What Does an R-Squared Value of 0.9 Mean?