Seattle tech firm F5 Networks, which has an engineer group in Liberty Lake, has been added to the S&P 500 index, the company said this week. F5 makes load balancing tools and software components that allow major Web companies to manage net traffic efficiently. Also joining the S&P 500 Index is DVD rental service Netflix.

Seattle tech company F5 Networks has hit a nice awards trifecta recently. We care because the publicly traded firm has a substantial presence in Liberty Lake, where a good number of engineers work on their network-optimization hardware and software.

It was listed by Forbes as among the 100 fastest-growing companies, landing in the No. 64 position.

Forbes also placed F5 among its “most trustworthy companies.” It came in with an AGR rank of 53, which is a score based on “accounting and governance risk.” The higher the score, the less risk the company has of exposing shareholders or investors to fraud or financial wrongdoing, according to Audit Integrity, a company that tracks that area.

F5 also landed on Forbes’ companies most actively involved in hiring right now. That list notes that F5’s sales growth and demand for products translates into adding between 80 and 100 hires per quarter. 

Company wide, F5 has added close to 300 positions since last October, said Alane Moran, F5’s director of corporate communications.

Three Washington businesses  — Amazon, Coinstar and F5 Networks — have been added to Fortune mag’s list of 100 fastest growing companies.

All three have headquarters in the Seattle area. F5, which makes network management services and tools, has an engineering office in Liberty Lake.

Amazon moved to No. 30 from its previous rank of No. 52. Bellevue’s Coinstar ranked No. 61, followed by F5 Networks at No. 64.

Fortune’s full list is here.  The Sept. 6 issue also features a section on Washington, profiling the state as a center for world-class innovation and featuring its new export initiative, designed to complement President Obama’s National Export Initiative.

You can see the Washington special section at ChooseWashington.com.

F5 Networks, a Seattle tech firm with a development office in Liberty Lake, is among 80 finalists for Washington’s Best Workplaces, chosen by the Puget Sound Business Journal. The winners will be announced later this summer. The best workplace award identifies firms that have excelled in employee benefit offerings, leadership culture, and work/life balance philosophies.

For more on the awards, try this Puget Sound Business Journal summary.

Founded in 1996, F5 Networks has about 1,800 employees with offices in 30 countries, and revenue of more than $650 million in fiscal year 2009. It develops advanced hardware and software solutions to optimize Web traffic for major companies and organizations.

When we say “major,” think very very big, like Microsoft, Amazon and major operators.