In response to a study that found Facebook's female engineers received 35% more rejections of their code than male engineers, the social networking giant has released its own study that found a difference by rank but not gender. Now the question has become, are female engineers rising the ranks at the same rate as their male peers?

The first study was conducted by an unnamed former Facebook engineer and viewed by the Wall Street Journal last Fall. She said she analyzed five years worth of code and found the 35% rejection rate, as well as that women waited 3.9% longer to have their code accepted and got 8.2% more comments and questions on it than men.

Code is, of course, what makes every feature, update and service on the social network work. (See Facebook TIPs Fiber Scale, Builds Connected World, Facebook Launches 3D Video Capture: Surround 360 and Facebook: Operations Comes First.)

Facebook called the study inaccurate and incomplete and conducted its own instead, which found no gap by gender, but one by an engineer's rank. Rather than debunk the original study's claims of gender bias, many are interpreting these new findings to mean Facebook doesn't promote its female engineers at the same rate as the males. It doesn't share its gender breakdown by its eight level of engineering roles, but has made public that 17% of its engineering roles are filled by women -- a low number, but not an uncommon one at tech companies in the Valley. (See Uber Employs 15% Women in Tech Roles.)

We'll be discussing gender bias and company cultures at Women in Comms' upcoming conference in Austin on Monday, May 15. You can register to join right here!

That there aren't enough women in engineering roles at Facebook or any tech company is no secret. It's a problem that many say they are trying to rectify starting with releasing annual diversity reports to bring transparency to the issue. Facebook has been a leading voice in this cause with COO Sheryl Sandberg as a well-known advocate for women, but it's also come under fire before for its hiring process for engineering roles. (See Facebook Steps Up Its Paid Leave Policies and What Facebook's Recruiting Woes Tell Us.)

Facebook CEO Mark Zuckerberg admitted to the WSJ that gender bias is an issue, but outside of optional bias training courses, it's unclear how the company plans to address it in any meaningful way.

"Any meaningful discrepancy based on the complete data is clearly attributable not to gender but to seniority of the employee," Facebook said in a statement. "In fact, the discrepancy simply reaffirms a challenge we have previously highlighted -- the current representation of senior female engineers both at Facebook and across the industry is nowhere near where it needs to be."

— Sarah Thomas, , Director, Women in Comms