[2] After graduating from Cambridge University in 1987 and working in advertising for three years, Langan joined Granada Television's drama serials department where she served as a script editor for daytime soap operas.
In April 2009, she was appointed Creative Director of BBC Films, giving her control of a £12 million annual budget and which projects are commissioned for development.
[6] In 1990, Langan began her career in film production as an assistant developer for Tessa Ross at British Screen.
[7] The following year, she responded to an advertisement for a script editor at Granada Television's drama serials department, located in Manchester.
[5][7] In 1993, Langan returned to London to work for Andy Harries at Granada's newly created comedy department, where she script-edited September Song, the television adaptation of An Evening with Gary Lineker, and the second series of Rik Mayall Presents.
The Perfect Match was broadcast in September 1995, and shortly afterwards, Harries asked Langan to develop more ideas from Bullen.
Langan produced Cold Feet, guiding Bullen through his script drafts, and hiring Father Ted director Declan Lowney to shoot it.
[10] For the series, Langan tried to achieve a written and visual style that differed from regular sitcoms by avoiding "one-liners and quick laughs" and hiring directors who had done little television work before.
Her only other project was producing David Nicholls' romantic comedy series Rescue Me with Tiger Aspect Productions for BBC One.
[16] In September 2002, Langan signed a new contract to develop new projects at Granada's combined drama, film and comedy department.
At the end of 2002, she began developing Peter Morgan's The Deal, a dramatisation of the political rise of Tony Blair and Gordon Brown.
[22] In September 2006, Langan made a low-key departure from Granada to take up a position as an executive producer with BBC Films.
The film was adapted by Peter Morgan, executive produced by Andy Harries, and starred Michael Sheen as Clough.
[5] Following David M. Thompson's announcement that he would be retiring from the post of head of BBC Films in September 2007, Langan was widely expected to take over his duties.
[30] In 2010, Langan also executive produced The Special Relationship—the final part of Peter Morgan's "Blair trilogy"—and StreetDance, the first British feature film to be made in 3D.