Mesut Altan graduated from Yıldız Technical University, Department of Mechanical Engineering in 1995. He worked as Project Coordinator at Cantes Klima between 1995-2002. In 2002, he left this company and became the founding partner of Birleşim Mühendislik AŞ, which produces mechanical system solutions.
In 2006, with the aim of establishing Birleşim Group companies, Birleşim İnşaat AŞ; In 2011, Birleşim Makina AŞ was added to the group companies.
In 2014, he signed a strategic partnership and acquired 100% shares of Erde Mühendislik, one of the leading companies in the electrical contracting sector, and turned it into an engineering company that produces electromechanical contracting solutions, which will be among the firsts in the sector together with Birleşim Mühendislik. In 2016, the Company opened the Ataşehir Park-Inn By Radisson Hotel and invested in the hotel management sector; in 2018, the Company added Toro Makina AŞ to its group companies and invested in the construction equipment sector.
As of 2020, Birleşim Grup Enerji Yatırımları AŞ- BGE, which started to serve in the field of renewable energy, has included Edikli SPP, Uluder SPP and Gülbahar SPP plants, all of which are licensed, respectively, under its roof. While realizing the Menekşe WPP investment in the field of wind energy, it added ZEN Energy to its energy group in 2023. With Zen Energy, solar power plants with a total installed capacity of 48 MWp were commissioned in Burdur, Eskişehir, Kırıkkale, Kütahya, Isparta and Uşak.
At the end of 2022, he acquired 70% of the shares of Solar Santral AŞ, which provides holistic services to its customers from project development stage to financing, from installation to operation of the power plant, for Solar Energy Based Electricity Generation Plants (SPP), and brought it to Birleşim Engineering subsidiary.
Mesut Altan continues to serve as the Chairman and Vice Chairman of the Board of Directors of Birleşim Mühendislik AŞ, Erde Mühendislik AŞ, Solar Santral AŞ, Birleşim Yeşil Enerji AŞ, Birleşim Makina AŞ and Birleşim İnşaat AŞ within Birleşim Group.