For the same reasons a resume is never enough to get you the job you really want, no one hires a new employee based on their resume alone. Qualifications, education, experience, it all matters, but most hiring managers quickly scan and sort resumes before moving on to the next step in the hiring process.

So how can you get better at reviewing resumes to identify the candidates you want to interview? The following is from Simon Wistow, the co-founder and VP of Product Strategy at Fastly, who looks for three key things on every resume. (Fastly is an edge cloud platform, which basically means it delivers content incredibly quickly by leveraging its network of servers around the world to reduce delivery latency and increase performance; the closer the content to a device, the quicker it's delivered.)

What three things does Simon look for on every resume?

Here's Simon:

Hiring good people is part art and part science. It takes a lot of time and energy to vet prospective candidates, so the interviewing process focuses on identifying the truly top people for the job.

The resume is overrated and doesn't necessarily give you the best sense of someone's strengths and weaknesses to determine whether they are worth exploring further. A resume can only take you so far.

But a resume does reveal how candidates want prospective employers to view them.

When looked at through that filter, resumes can be useful, if you know what hidden clues to look for. After interviewing hundreds of candidates over the years -- I helped to grow our engineering team from one to 100 in five years -- here are the top three things I look for when reviewing resumes:

1. Obscure experience.

Most companies look to see if candidates have experience that is the same or similar to the position they are hiring to fill. Startups, in particular, are under pressure to move fast and they're hiring for specific roles.

But I don't hire people to perform only a current task; I hire people who can do what I need done now and who have the potential to do what I need done in six months. This usually means I'm looking for people who can envision the past, present, and future and who can problem solve. I'm looking for people who have the tenacity to chase down problems to get to their root cause.

You want to find someone who can grow as the company grows -- someone who can step up and take leadership or mentorship roles as the company grows.

Information that might signal a red flag or be overlooked by others -- tasks that are weird, obscure, or seemingly irrelevant -- leap out at me. They can say a lot about a person.

For example, odd details can indicate someone has the ability to learn new things and be adventurous, instead of coasting on a skill set they already possess. Small details can show a person's willingness to move outside of their comfort zone at work.

I once hired an engineer whose resume mentioned that he had developed "networked laundry machines," and he turned out to be one of our most creative hackers.

When you have experience outside of the tech bubble, you take on a new perspective and can come at a problem (and solve it) differently.

2. Depth or breadth?

People are typically grouped into generalists or specialists; rarely is someone both. Startups need both types of people at different stages of their company's growth, and for different projects.

Look for depth of knowledge in a particular area, or breadth of knowledge across a spectrum of areas. I want to see that the individual has mastered an area of work and will be a go-to person. Or, I want to see that the individual has worked on a wide variety of domains: Every new space you work in gives you more tools you can bring to bear on a problem or a different way of looking at an issue.

If all you've worked on are Ruby-based web apps, then every issue will look like a Rails-shaped nail.

3. What's not there.

One of the main reasons I don't put a ton of faith in resumes is because they are implicitly biased and don't tell the whole story. Resumes tell you only what the candidate wants to reveal, accentuating flattering efforts and omitting others. Two people who had identical jobs and similar performance will likely have resumes that provide dramatically different views.

There's also a bias attendant during job interviews, but that bias favors different skills than those revealed in written form. Conversational skills and good chemistry can turn a candidate who was mediocre on paper into a promising new hire. Likewise, excellent job experience at reputable companies and perfectly aligned skills can keep a candidate in the running even if they bomb the interview.

It's also important to note that resumes can differ by culture; a British CV is very different than an American resume. It's important to take these nuances into account.

Your goal is to anticipate these biases and be prepared for them. Try to determine from what's not on the resume what the candidate doesn't want you to know or find out.

Hidden red flags can include frequently changing jobs, software monoculture, stuck in the same role for too long... use your experience in your industry to create your own list of trouble signs, and then pay close attention to what is not on the resume.

Of course your assumption may be wrong. How will you know?

That's what the interview is for.