Rapidly scaling your business can involve going on what might feel like a hiring spree.
Every entrepreneur dreams of launching something that gets an instant, positive response from the market. But being a runaway success can come with its own challenges -- one being the need to build up a team that'll help your business continue to grow, and to do so fast.
In this atmosphere, it can be tempting to try to fill seats as quickly as you can, and let hiring quality slip. But not taking the time to be thoughtful about who you're bringing on can be a disastrous mistake. As the saying goes, it pays to hire slow and fire fast.
My company, Funding Circle, doubled in size in the U.S. over the course of about a year. This means I've interviewed a lot of candidates at various levels. These are the four big things I usually look for, above and beyond the specific skills required to be successful in a particular role:

1. Mission and values alignment.

The fundamental thing I look for in any candidate, regardless of department or level, is alignment with our company's mission and values. We've taken a lot of time to define exactly what our company has set out to do in the world, and the five traits and qualities that we feel are most important.
Anyone who wants to join our team should demonstrate that those same things matter to them.
To test whether a candidate fits this qualification, think about what living your values and mission would mean for someone in that particular role in your company. Ask questions that get to the heart of how they think about those things and what they've done in relation to them in the past.

2. A problem-solving mindset.

In a rapidly scaling business like ours, the challenges we face day-to-day are often new and ambiguous. Most roles require someone who can remain graceful under pressure and think independently.
Another useful skill is the ability to put structure around problems -- the ability to take an amorphous issue and think about it in a systematic way.
Situational interview questions, in which a candidate describes how they would handle a hypothetical scenario, are useful in teasing out problem-solving abilities. The person's conclusion is important, but pay just as much attention to the thought process they used to reach it and how they defined the problem.

3. A clear vision about how they fit in.

Few jobs today require order-taking automatons. For every position, I am looking for candidates who demonstrate leadership qualities and a sense of vision for themselves, their team, and the company. Even if the role doesn't involve leading an office or a department -- today -- the team member will likely lead a project or a process at the very least.
You can ask the person about their leadership style and goals, but you'll also want to pay attention to whether they demonstrate other skills and traits you expect a leader in your organization to have -- for example, how they think about mentorship or whether they learn from their mistakes.
You should also evaluate the person's perspective about the business and its capabilities, an understanding of the broader field, and a view about how to succeed with those factors in mind.

4. Strong communication skills.

This may seem like a basic one, but it's hard to overemphasize just how important good communication skills are. To be successful in many roles, you need to be able to communicate in the right way with many different types of stakeholders.
Interviews are good opportunities to assess someone's communication skills. Are they clear about what they are looking for and how that aligns with the role they've applied for? Are they honest? Do they avoid giving superficial answers? Do they know who they are and what they want, and clearly and consistently communicate this throughout the interview process?
An interview is an opportunity to determine whether a job candidate is a good fit for an open role -- and vice versa. By focusing on these four areas, you can hone in on a few of the things that matter most to the success of both the candidate and your company.