Technology

A weeder task is a super simple programming task that should be second nature. Some options for different stacks:

• JavaScript - use array functions to turn the input into a given output (2-3 lines of code)
• React-specific - pass data from an input field to a text field in separate components (5-10 lines of code, we provide the rest)
• Python - various list, dict, or set comprehension tasks
• Rust - something with iterators or traits

Basically, we just want to know if they can write basic code in the position we're hiring for.

I only vaguely know what you mean by “We were hoping to say they needed to write some tests to get a code review”.

The "programming challenge" isn't really a challenge for programming skill, but more of a software engineering challenge to see how they turn vague requirements into a product the company could ship.

Let's say the task is to build a CLI store, where the user inputs items and quantities they want to buy, and the app updates inventory after a sale. For the sake of time, we'll say data doesn't need to persist between runs.

I think any developer could build something like that in about 15-20 min, maybe less if they're familiar with that kind of task. In Python, it's basically an input() loop that queries an "inventory" dictionary and updates an "order" dictionary.

However, there are also a bunch of corner cases:

• user inputs invalid item
• insufficient inventory
• invalid quantity
• add the same item twice (not an error, maybe a warning?)
• what if user decides to abandon the purchase and start over?
• if we make it concurrent (i.e. a server with multiple users), how do we ensure inventory is correct?

After they build the basic solution, we ask them an open ended question: how confident are you that the code is correct? They wrote it in 20 min or so, therefore the confidence should be pretty low. I'll then ask what they'd do to get more confidence.

A good software engineer doesn't only want to ensure the happy path works, but that the corner cases are handled and those uses will continue to work regardless of what other developers add in the future. So I'm looking for one or all of:

• peer review of the code
• unit tests
• documentation

If they say it's perfect and to ship it, that's concerning, especially if I identified an issue in the process of them solving it. We identified the same issue twice for that candidate that relied on AI, and they still said "ship it," and we also noticed other issues as well that we didn't tell them about.

So we're looking both for competence and self awareness. Know your stuff, but also recognize your limitations. Meeting the requirements is only half of development IMO, you also need to maintain it long term.