He is the chief executive of Studio Lambert, one of All3Media's production companies,[1][2] which produces Gogglebox, Undercover Boss, Squid Game: The Challenge, Race Across the World, The Circle and The Traitors.

[3] In Lambert's previous job at the independent production company RDF, he was responsible for global unscripted hits such as Wife Swap, Faking It and The Secret Millionaire.

Between 1992 and 1994, he produced and directed a six-part documentary series for BBC2 about the Foreign and Commonwealth Office which was filmed in Northern Iraq, the former Soviet Union, Bosnia, Thailand, Saudi Arabia, Europe, the US and in Whitehall.

[21] Lambert continued working with Adam Curtis, executive producing his The Century of the Self (2002), The Power of Nightmares (2004) (winner of BAFTA best factual series award 2004), and The Trap (2007).

In 2007, Lambert resigned from RDF after taking responsibility over a misleadingly edited trailer for a BBC documentary which appeared to show the Queen storming out of a photoshoot with Annie Leibovitz.

[28] Lambert's first major formatted show in his new company was Undercover Boss, which started on Britain's Channel 4 in 2009 and has been produced in dozens of countries around the world.

[29] Studio Lambert produces an American version which premiered on CBS in February 2010 immediately after the Super Bowl to a record-breaking audience of nearly 40 million viewers.

[30] It went on to become the highest rating new show of the 2009-10 television season with an average audience of 17 million viewers[31] and to earn an Emmy Awards nomination for Outstanding Reality Program every year from 2010 to 2016, winning the category in 2012 and 2013.

[49] In 2021, Disney+ announced that Seven Stories, the other scripted company Lambert is involved in as chairman, was making Nautilus a major live-action series based on Jules Verne's 1870 novel Twenty Thousand Leagues Under the Seas.