5 interesting things (11/3/2020)

Never attribute to stupidity that which is adequately explained by opportunity cost – if you have a capacity for only 10 words, those are the 10 words you should take – “prioritization is the most value creating activity in any company”. One general, I really like Erik Bernhardsson writing and ideas, I find his posts insightful.

Causal inference tutorials thread – check this thread if you are interested in causal inference.
The (Real) 11 Reasons I Don’t Hire you – I follow Charity Major’s blog since I heard here in ״Distributed Matters” in 2015. Besides being a very talented engineer, she also writes about being a founder and manager. Hiring and is hard for both sides and although it is hard to believe it is not always personal and a candidate has to be a good match for the presented company, for the future company, to the team. The company would like to have exciting and challenging tasks for the candidate so she will be happy and grow in the company, And of course, we are all human and make mistakes from time to time. Read Charity’s post in order to examine the not hiring decision from the employer’s point of view.

The 22 Most-Used Python Packages in the World – an analysis of the most downloaded Python packages on PyPI over the past 365 days. Some of the results are surprising – I expected pip to be the most used package and it is only the fourth after urllib3, six and boto core, and requests to be ranked a bit higher. Some of the packages are internals we are not even aware of such as idna and pyasn1. Interesting reflection.

Time-based cross-validation – it might seem obvious when reading but there are few things to notice when training a model that has time dependency. This post also includes Python code to support the suggested solutions.

DevSkiller 2019 report – few comments

I read a blog post about DevSkiller report analyzing some trends and I read the original report and I have some comments to make.

“Companies from Israel are the most selective”

According to the post, companies in Israel are considered the most selective since they consider only 12.26% of the developers they test. Another point of view is that Israeli companies give less weight to résumés and would rather test the applicant skills. This can increase the diversity and give a chance to more people. I think that it is a good practice for an industry that lacks more than 10,000 professionals (see here)

“72% of companies are looking for JavaScript developers and JS is the most popular IT skill developers are tested in (40%)”

JavaScript is used both front-end (e.g. react) and back-end tool (e.g. node.js) and I think that the popularity 

. I think grouping it together is too broad. Also, the SQL skill is somehow a side requirement of many positions and is almost worthless on its own. The big gap between JavaScript (40%) and HTML\CSS (20%) is weird, specifically when they compare it to the StackOverflow 2019 report where they were JavaScript had 67.8% and HTML\CSS have 63.5% and they were one after the other. The numbers themselves do not matter, just the gap and the order.


On a side comment, interpersonal skills such as team player, leadership, responsibility are ignored in this report and that’s a shame. They are sometimes more important when hiring someone. 

“React, Spring, ASP.NET, MySQL, HTML, Data Analysis, and Laravel are the most popular technologies in their respective tech stacks”

CSS is a tech stack? Weird analysis from my point of view, maybe web development would have been a better title.

Is it a surprise that HTML and CSS are tested together? I find it hard to believe that an employer looks for an employee that is skilled only with one of those, they are tightly coupled.

In this section in the post, I miss a mention of NoSQL technologies.

General comments

Obviously, they use their data which is great but there might be a selection bias to pay attention to. For example, companies that look for JavaScript developers are not able to screen for themselves and therefore use their services. Comparing to companies the loop for Python developers. In the section about technologies tested together, they point out that the most common combination last year was Java+SQL and this year it is JavaScript + CSS. Maybe their screening service for Java+SQL is not as good as their screening for JavaScript + CSS and therefore companies do not use it.

The completion rate of the test is impressive (93%).

There is a detailed analysis of the geography of the hiring companies and the candidates’ origins. I am also interested in demographics such as age, gender, marital status. I know that not everything is legal to have or ask. But I wonder if parents are more likely or less likely to complete the tests (or even start them). Are women as likely as men to pass the tests? Are there feminine and masculine technologies?

Data about years of experience and the correlation to technologies used and the probability passing the tests would also be interesting.