[1][4] In 2013, Lagum took part in a casting call for Africa's Next Top Model taking a 16-hour bus ride from Kampala to Nairobi.

She was later called by host Oluchi Onweagba and was chosen to fly to Cape Town as one of the twelve finalists for the show.

[5][6] Lagum quickly gained notice from the judges and guests of the show, winning several best photos along with the opportunity to appear in an editorial spread for South African Elle for having received best picture in week 9.

Lagum has also appeared in Lookbooks for Hugo Boss, Area, Narciso Rodriguez, Kenzo, Acne Studios, Guerlain, Nordstrom, Barneys New York, Sonia Rykiel, Saks Fifth Avenue,[10][15][16] as well as advertorials for Kenzo[17][18] and advertising campaigns for Marc Jacobs, shot by David Sims.

[22] Lagum played the role of Queen of Sheba in the fantasy romantic drama film Three Thousand Years of Longing directed by George Miller which had its theatrical release in 2022.