The Washing Machine Test
Over the course of my career, I’ve interviewed and recruited hundreds of people, candidates for development, team leaders, system architects, and product managers. But what makes some candidates more appealing than others?
Success in all areas requires planning and keeping your eye on the prize, and anyone who is involved with planning or system development must be able to see the big picture and the product’s essence. I expect developers and product managers to understand the Why and the What, before getting into the How.
What makes me smell success?
Usually, interviewers ask candidates to describe a system they helped developed, or the company they work for. They are looking for the details. I, however, expect a candidate to give me the big picture of the product or company, before diving into the details.
Over the years, I honed in on some clues and developed my own little “test” which is indicative to me about the candidate’s ability to see the big picture. Can they capture the character and essence of the product in one sentence?
They need to answer this question: In one sentence, describe what a washing machine does.
The answer is trickier than it seems; take a second to try and answer it yourself before moving on. Can you answer the question?
Finding the essence and seeing the big picture
Hint: The answer I’m looking for is the what, not the how. I want to hear “it washes clothes” or “it cleans clothes”, short and sweet. I asked What it does, and nothing else.
The essence?
- Design a chair for me and not a “plywood square with 4 wooden legs”.
- Explain the feature to me, don’t show me your code.
Some developers are terrific at code writing, but it they can’t explain their feature to me, it tells me 1 of 2 things:
1. If they developed that function, their design skills are poor. A function should have a single, clear purpose.
2. If it was developed by someone else and they use it, it means they don’t really understand the function.
Those are both terrible conclusions.
Here are some answers
In answer to my test question, many developers focused on the How and explained the water volume, the detergent requirements, the fabric softener, which, naturally, required more than one sentence.
- “Mixes cloths in water… fills water… turns them around in the water… ”
An answer of a candidate for Chief Architect. Of course, he failed. 🥺 - “Cleans my clothes. I put them in and expect to get them wet but clean.”
Pass. Answered the “What” and has a sense of humor. - “Removes dirt from the clothes.”
Passed, but explained the requirements and not the “What”. - “Keeps us healthy, and the wife happy. But the naïve answer is that it cleans clothes.”
Passed, but not PC. What might that mean later on! - “Loads the laundry, shuts the door, checks the existence of detergent, tries to fill water, fills water, checks if there is electricity, starts to turn the drum, checks which program the user chose and for how long and how hot, extracts the water, beeps and open the door.”
A real answer! Failed with flying colors. (I hope they used a detergent that is color-safe). 😬 - “Cleans our clothes when they are dirty.”
Good point! It cannot clean what is already clean. Pass. - “Turns clothes fast and makes them rub one against the other while it puts in water and detergent in turns — some kind of algorithm.”
Oh boy. Fail. - “Takes allegedly dirty clothes and cleans them with water and detergent.”
Ok, I’ll pass him begrudgingly. 😕 - “Extracts clean clothes.”
A results-oriented guy. Pass. - “Takes the dirt out the clothes and pours it out.”
Negative-result oriented guy. Doubt. - “Tumbles the clothes, floods them with water and soap and causes the dirt to come out”
Fail. - “Cleans.”
Answer from 2 separate candidates. hmmm… true but… - “Receives orders what to do and you actually choose a program for it to implement.”
Maybe too abstract? Fail.
And the candidates, who proved to be the best product manager material, answered not just the “What” but also gave the “Why”. They not only told me what the appliance does, they also explained the purpose. This is indicative of someone who asks questions and needs to get to the bottom of an issue, understand the reason for doing something, and doesn’t just follow orders. That is the trait of a great Product Manager.
These are some answers from some great Product Managers:
“Frees up time.”
What a great point! Together with other great inventions such the TV dinners and infant formula, the washing machine was one of the inventions that liberated women from their traditional role and allowed them to develop careers. (I heartily recommend reading — Fifty Inventions That Shaped the Modern Economy which discusses these and other inventions that have impacted our lives today.)
“Saves life, working on a daily basis. Keeps things hygienic. “
Hygiene? It’s plausible, it shows thought about the purpose, but it’s too vague overall.
“Takes a manual labor and turns it into an automatic operation with minimal involvement of the operator”.
And my favorite …
“Democratization of the cleaning process — instead of sending the laundry to some central place, you can now do your laundry in the comfort of your own home.”
Bottom line
Here’s my takeaway:
You might argue that it’s not a “scientific” test and that I am biased, but in the majority of cases, the answers from the washing machine test correlated directly with the impression they made on me during the rest of the interview. I was rarely disappointed.
Use this test (don’t forget to credit me :) ), and make sure to send me any interesting answers you get.
