In some work with a small international consulting firm, I was asked to support them in developing a strategy. The creation of this strategy was a fun and easy process. However, democratic management, glacial decision-making and being super nice to each other defined the organisational culture and this got in the way of execution. The strategy remains on the shelf 18 months after its creation. The execution was a disaster. (Also read: 49 tough CIO interview questions.)

Culture matters. It may not be something you spend much time thinking about but it underpins how people operate in a team or company. It's like a perfume in the air programming attitudes and behaviours. Team and company cultures are intertwined and interdependent. As a leader in your company, what matters is to be very clear on the culture within both your team and the company. This knowledge will help prevent smart plans being undermined in the way of the consulting company in the opening story.

As a mentor and coach at a London accelerator, I've had the privilege to work with a few tech startups. Those with single digit employees lose no sleep over culture, and understandably so. Some combination of all staff are involved with almost all the decisions in the company. It's easy for them to stay focused on what matters when they practically live 24 hours of each day together.

This changes with the size of the startup. One company I advise has 40 employees in two locations. As this CEO looks to expand the company, he's faced with several important questions about staff and the hiring process. What should I be looking for in the interview and how can I make sure others are looking for the same criteria? Who was the right person for the new role? Why is the operations person not fitting in?

By his own admission, the CEO is spending too much time dealing with people who don't fit into the company. Getting this wrong is catastrophic.

At the heart of these questions is what is the DNA of the company being built. This DNA or culture provides a framework to ensure the company hires and grows in a way that is intentional. The culture defines the type of people who will fit in, the behavior that is rewarded or not, and even the organisational structure.

The work with the CEO of the startup is to think through a company culture that matters to him. Given this is his startup, it will be closely aligned to his values.

It's fascinating to have the opportunity to really be intentional about both creating and living the culture that matters. I don't doubt that this clarity around the culture will be a defining feature of the company's success.

Whether you run a company, or manage a team, there is an opportunity for all of us to be much clearer around the successful DNA of our own teams. The lesson is to not ignore that which we can't see. The culture will perfume your team and company - you get to choose if it's a good smell or a bad one.