The 11 best summer internships

This winter, many college students are gearing up for their summer of working, networking and making $6,000 per month or more.

Decades ago, college students may have been happy to earn some pocket money over the summer by waitressing or being a lifeguard, but high-achievers want their summer experiences to benefit both their careers and their bank accounts.

During the winter months, top U.S. corporations from Apple (AAPL) to Chevron (CVX) post summer internships ads, looking for the right students to fill their rosters. Employment site Glassdoor, which has more than 27,000 open intern positions currently posted, noted that securing that plum summer role may require students to jump through several hoops.

"What has changed in recent years is the intern interview process mirrors the real employee interview experience," said Scott Dobroski, associate director of corporate communications at Glassdoor.

Interns may first have an initial phone interview, which, if successful, could be followed up by a second phone interview. After that, plan on an in-person interview to meet the team they could end up working with during summer break, he added.

While that might sound like an extensive process for a temporary job, Dobroski noted that interns at tech companies stand to make $6,000 per month, or the equivalent to an employee earning $72,000 per year. That's far higher than the U.S. median household income of about $52,000. After graduating, interns are sometimes hired for full-time roles, while many make valuable professional connections.

In compiling its list of highest rated companies for internships, Glassdoor considered the rating the company received from its previous interns, as well as the difficulty level of the interview process.

Read on to find the top 11 companies for internships.

​1. Facebook

This marks the second year in a row that Facebook (FB) has reached the top of the list. Open summer internships include roles in business development, analytics and design. Would-be applicants are told they'll be working on problems such as building software and mining data for business insights.

Interns at the social-media service can make more than $6,000 per month. Prior interns praised Facebook as providing them with the opportunities to work on challenging, interesting tasks, the study found.

Getting a summer job isn't as easy as making a friend on Facebook, however. The interview difficulty process was rated 3.1 on of a 5-point scale, making it one of the most difficult among the top 11 companies.

​2. Chevron

This multinational energy company, which is making its debut on Glassdoor's list, is looking for a range of interns, from students focusing on finance to those studying engineering. Interns often make $6,000 per month, according to data reported on Glassdoor.

The interview process is also deemed easier than that at Facebook, with interns giving Chevron a 2.5 rating for the difficulty of its interview process.

Former interns praised the company for its good pay and benefits, and the professionalism of its staff.

​3. Google

Google (GOOG) has become known for its tough interview process for full-time hires, with applicants asked questions such as "How much does the Empire State Building weigh?"

Interns say getting a summer job at Google is tough, giving it 3.3 points for interview difficulty, or the second-highest among the 11 companies on this list. But once inside, interns say Google provides a great experience including training classes, accessible workers and supportive managers. Interns report making $6,000 to $7,000 per month.

​4. Quicken Loans

The largest online retail mortgage lender scores points for providing students with a great summer work experience in the finance industry. The interview process was less intense than at tech giants such as Google and Facebook, with Quicken Loans receiving a 2.7 difficulty rating.

Interns at Quicken are probably making less money than at a tech giant, more in the range of $2,000 per month, Glassdoor's Dobroski said. Former interns describe their summer jobs as teaching them a great deal about the mortgage industry, while working at a forward-thinking company.

​5. eBay

Like other tech companies, e-commerce giant eBay (EBAY) can be harder to crack than nontech businesses, with interns ranking the difficulty of its interview process at 3.0, or just behind Facebook.

Interns report working with top executives, including the CEO, and being included by regular employees. Other bonuses include "Bagel Wednesdays" and what interns call "a very competitive salary," which can be $6,000 per month or more.

​6. Yahoo

While the one-time Internet giant is still trying to find its footing under CEO Marissa Mayer, Yahoo (YHOO) has nevertheless jumped to the No. 6 spot on Glassdoor's ranking from No. 14 last year, Dobroski noted.

"They are very well aware they need the best and brightest to compete with the likes of Google and Apple," he said. That's providing great internship opportunities for students.

The company had one of the lower ratings for interview difficulty among tech companies, scoring a 2.9. Former interns said Yahoo's workers are dedicated, making for a good workplace.

​7. Epic Systems

While not a household name, health care software company Epic Systems ranked highly among interns for its combination of good pay, interesting projects and flexibility. Its interview difficulty rating is 3.1, or on par with Facebook.

Based in Wisconsin, the privately held company touts its eco-friendly buildings and its headquarter's 811-acre campus. Interns can make about $5,000 per month, according to Glassdoor.

8. Schlumberger

Schlumberger (SLB), the world's largest oilfield services company, earns a 3.0 rating for the difficulty level of its interview process, the same as eBay. Interns can make between $4,000 to $6,000 a month.

Interns praised the company for providing a chance to learn about the oil and gas industry, while working in a helpful environment.

​9. NBCUniversal

The media giant, owned by Comcast (CMCSA), has an internship program that offers summer roles in departments ranging from business development to film production. Interns can expect to make about $2,000 per month, Dobroski said.

The interview difficulty rating is 2.9, putting it on par with Yahoo. Former interns praised NBCUniversal's professional development sessions that are paired with summer work experience.

​10. Boston Consulting Group

This management consulting firm might be a great place to work during the summer, but just scoring the job is going to be tough. BCG earned a 3.8 rating for its interview difficulty level -- the highest on Glassdoor's survey.

The company says its internship program provides students with the chance "to experience the life of a consultant." One former intern said BCG employees and management were friendly, while career development is a priority.

​11. Apple

The most valuable corporation in the U.S. is also one of the most desirable places to find a summer job. And it has one of the tougher interview processes, with interns giving it a 3.1 ranking, like Facebook.

Undergrad students can find internships in fields ranging from design to operations, according to Apple, which describes its summer opportunities as "hands-on learning at its best."

The best of the rest

Another 14 companies are on Glassdoor's list for best internship opportunities in 2015. Below are those companies, ranked from No. 12 through No. 25.

12. State Farm

13. Microsoft

14. Intel

15. Walt Disney

16. Qualcomm

17. ExxonMobil

18. National Instruments

19. Morgan Stanley

20. Procter & Gamble

21. Cummins

22. Liberty Mutual Insurance

23. PepsiCo

24. Hewlett-Packard

25. Broadcom