“I don’t know” is almost always the wrong answer.

Whether you’re asked about the circumference of the Earth, the number of cups in a gallon, or the land speed velocity of an unladen Swallow – answering, “I don’t know,” is wrong 100% of the time.

While I would never advocate making up an answer in the hopes of your inquisitor not knowing the answer themselves, It’s never okay to say only “I don’t know,” and leave it at that. It is important to admit your knowledge gaps, but to not seek to fill them in is selling yourself short.

Monty Python – crossing the Bridge of Death

When you reach a mythical ‘Bridge of Death,’ which you must cross, the Keeper of the Bridge requires you to answer three questions. Telling this guy you don’t know the answer, is a really bad idea. After all he will cast you into the Gorge of Eternal Peril if you get it wrong or don’t know the answer.

Take your time, ask clarifying questions if need be, but if you really have no idea, the correct answer is “I’ll find out.”

Nearly every interview I’ve been on has included a question or two that I flat-out didn’t know the answer to. Each time, I made sure to remember or write down the question that had stumped me and to research the answer afterwards. With a little time and concerted effort, you can find the answer, and it’s a great opportunity to follow-up.

Ultimately, the answer to anything you don’t presently know is, “I don’t know … yet.”

On the topic of changing project or job

I used to think that changing jobs every couple of years was risky and could lead to less job security.

In the last couple of years, I have learned that the inverse is true. (at least for my industry and skill-set.)

I’ve stopped caring whatsoever about annual performance assessments and “moving up in the company” but rather focus on delivering projects successfully and keeping my eye out for the next cool project to work on. Outside your current company, nobody cares about your eleven-star annual reviews at another company – nobody.

There are enough failing software projects to jump into and get back on track to last me many lifetimes.

Software projects don’t (and shouldn’t) last forever. If you stick around after it ships, and v1 should ship in a year or less, you’re either doing maintenance or put onto the next project the big wigs deem to be important work for your team. At that point, don’t limit yourself to the project you’re given unless you can be passionate about it. Some folks can be passionate about whatever project they are on currently – and in a lot of ways I envy them- but as a “glass was designed twice as large as it needs to be” engineer, I cannot.

Find something you’re passionate about. I promise you it’s out there.