Small companies trying to scale naturally focus on how to hire the right people to fuel their growth. What often gets lost is what happens when an employee isn't the right fit: in terms of skills or, just as likely, in terms of the company's culture.

The following is a guest post by Joel Gascoigne, the co-founder of Buffer, a social media management tool that lets you schedule, automate, and analyze social media updates.

Here's Joel:

One of the things I enjoy most about building a company is focusing on culture and thinking about how to create an awesome team that is a joy to be part of. A large part of this is creating a set of values and then trying to gather people who feel at home in that environment--and with each other.

Because of our focus on culture we did a number of things early on at Buffer, like try to create a transparent company. But one realization my co-founder Leo and I eventually had was that if we truly want to focus on creating a great culture it would be inevitable that some people would not work out and we would have to ask them to leave.

There is very little written on the subject of firing people, and it's a hard thing to talk about, especially when you are still small. However, since one of our highest cultural values is transparency, for some time I have felt we were not being true to our values by not talking about it.

Hiring for Skills vs. Hiring for Culture

To put things in perspective: Buffer is now a team of 13. Along the way, we've actually let six people go. Fortunately we've never had financial struggles; all of these decisions were based around culture fit.

When we started Buffer I had no concrete ideas about culture. We grew very quickly and my instinct was to fill the gaps we had with the most skilled people I could find.

Once we reached seven people I started to see the importance of building a cohesive team that works well together and is a lot of fun to be part of. A major part of achieving that goal is defining your culture so you can find people who are a great fit for it. So that's when we put our ideas into words and created our cultural values. Then we began to rigorously hire based on those values.

So we've evolved our hiring process: Along with finding people with the right skills, we focus on finding people who are positive and happy, who focus on self improvement, who are humble and grateful, and who will be comfortable with our extreme transparency.

We have what we call a "Buffer Bootcamp," essentially a 45-day contract period with one on one feedback at two weeks, one month, and 45 days. A key goal is to determine whether Buffer is a good fit for the person who may join the team. Not only do we want to make sure that the employee will be a good fit for our company--we also want to ensure our company will be a good fit for the employee.

Why Firing Is Hard, but Important

With this more rigorous process in place we found that some people didn't fit the culture and letting them go was inevitable. Surprisingly, the very act of letting people go has shaped our culture more than anything.

All six employees we let go were great people who did fantastic work. We just realized that they were not a perfect fit for our culture and it made sense to part ways.

It also made sense for them: keeping someone around who is not a great fit is one of the worst things that could happen to them. The feeling of relief when I have let someone go has almost always been mutual; they also felt a sense of relief. I keep this quote from Jim Collins on my wall to remind myself to think in this way:

"Waiting too long before acting is equally unfair to the people who need to get off the bus. For every minute you allow a person to continue holding a seat when you know that person will not make it in the end, you're stealing a portion of his life, time that he could spend finding a better place where he could flourish."

We've had to make tough team changes, but along the way we started to see a ratio emerge: we now know not to be surprised if about one in four of the people we hire don't work out.

While that ratio might seem high, it's backed up by someone as experienced as Silicon Valley investor Marc Andreessen: "If you are super-scrupulous about your hiring process, you'll still have maybe a 70 percent success rate of a new person really working out--if you're lucky," he says.

Does that mean letting a person go is easy? Of course not. We're constantly trying to find the right balance and trying not to be too hasty with our decisions if we feel a slight misalignment with culture. That said, though, if you are not deliberate about culture you can easily end up with a bunch of people who don't work well together. Neither you nor your employees want that to happen.