Each year, Google receives more than two million job applications from around the world and hires several thousand of those candidates.

It takes an average of six weeks to secure a hire, and every candidate needs to be screened by their potential boss, potential colleagues, and a hiring committee.

"If you wondered if this takes a lot of Googler time, it does," Google's SVP of People Operations Laszlo Bock writes in his book, "Work Rules!". But he says that time has been cut down significantly by making the hiring process more efficient.

In the early days of the company, hiring would take four to 10 hours of a manager's time each week, with top executives spending a full day on it. By 2013, the company had grown to 40,000 employees but had slashed that time to one and a half hours a week. (Today, the company has more than 60,000 employees.)

Bock explains that years of research and experimentation helped Google get hiring exceptional people down to a near science. "There are four simple principles that can help even the smallest team do much, much better at hiring," he writes.

We've explained them below.

1. Set an uncompromisable high standard.

Google's board selected Sundar Pichai to succeed Larry Page as Google CEO last August.

You will be able to quickly determine if someone is worth even an initial interview by setting the bar high and not budging it.

"Before you start recruiting, decide what attributes you want and define as a group what great looks like," Bock writes. "A good rule of thumb is to hire only people who are better than you."

This applies to all positions, he explains. If you're hiring an administrative assistant, don't simply look for someone who can answer a phone and schedule your meetings; find someone who will make your job easier by organizing your time and priorities better than you ever could.

And if an employee search is taking longer than you would like, be patient and concentrate more of your effort on the task.

"Do not compromise," Bock writes. "Ever."

2. Find candidates on your own.

Google works with some recruitment firms, but only in specific situations in which outside expertise is a requirement, such as building a new team in another country.

The company has used third-party job boards like Monster in the past, but pulled back from them after its reputation grew sufficiently, mostly because it found that too many of those sites' users send out generic mass job applications.

Today, Google relies on its own careers portal and the referrals it solicits from Googlers. And when your company begins growing, Bock says, "ask your best-networked people to spend even more time sourcing great hires."

He also recommends that managers make use of LinkedIn, Google+, alumni databases, and professional associations to discover talent.

3. Put checks in place to assess candidates objectively.

An organization the size of Google can afford to have a large group of people spend time with each candidate, but even smaller companies need to avoid placing the burden of hiring someone onto one individual.

"Include subordinates and peers in the interviews, make sure interviewers write good notes, and have an unbiased group of people make the actual hiring decision," Bock writes. "Periodically return to those notes and compare them to how the new employee is doing, to refine your assessment capability."

4. Provide candidates with a reason to join.

Google's Mountain View headquarters.

Jonathan Rosenberg, former SVP of products and current advisor to Alphabet CEO Larry Page, used to keep 200 Google employees' résumés in his office.

"If a candidate was on the fence about joining Google, Jonathan would simply give them the stack and say: 'You get to work with these people,'" Bock writes.

According to Bock, the candidate would look through the impressive collection, including everyone from the inventor of JavaScript to Olympic athletes, and ask Rosenberg if he had cherry-picked them — to which he would honestly reply no. The technique worked every time.

"Make clear why the work you are doing matters, and let the candidate experience the astounding people they will get to work with," Bock writes.