Ending a year in which it was criticized for a lack of diversity in its work force, Twitter, the social media service, has hired a new executive in charge of dealing with the issue.
Jeffrey Siminoff has replaced Janet Van Huysse as the companyâs vice president of diversity and inclusion, according to tweets written by Mr. Siminoff and Ms. Van Huysse.
Mr. Siminoff, 50, was previously head of diversity at Apple, and he co-founded Out Leadership, a lesbian, gay and transgender advocacy organization.
Twitter is facing difficult business and cultural transitions. The companyâs stock has fallen about 37 percent this year as its leadership team, which was overhauled over the summer when Jack Dorsey returned as chief executive, has struggled to attract new users and advertisers.
In October, Twitter issued a dismal financial forecast that eclipsed otherwise healthy quarterly results.
Twitter confirmed Mr. Siminoffâs hiring on Tuesday, but declined to comment on the criticisms that it had faced over its number of female and minority employees.
Employees at Twitter have openly discussed Twitterâs difficulties in hiring and retaining women and minorities, an issue that arose most recently in November, after the San Francisco company cut more than 300 jobs.
The Rev. Jesse Jackson, the civil rights leader, wrote to Mr. Dorsey that he was concerned Twitter had laid off a disproportionate number of minorities and asked the company to release a breakdown of the workers affected. And in a widely read blog post, Leslie Miley, a former engineer, wrote that after the job cuts, âTwitter no longer has any managers, directors or v.p.s of color in engineering or product management.â
Mr. Miley wrote that black adults accounted for about a quarter of Twitterâs users, but black employees made up about 2 percent of the companyâs work force.
Ms. Van Huysse, Twitterâs diversity head at the time, wrote in a blog post in August that Twitter had set a goal to have women account for 16 percent of tech roles and 25 percent of leadership roles.
In the United States, Twitter also planned to increase the number of African-Americans and Hispanics in tech roles to 9 percent and in leadership roles to 6 percent, according to the post.
Twitter was committed to becoming a more diverse company âto reflect the vast range of people who use Twitter,â Ms. Van Huysse wrote. She left after six years at the company and has not announced what she will be doing next.