Malgosia joined WindEurope in 2004, working her way up from intern to deputy CEO. She is responsible for all business operations, PR and membership strategy. She was announced one of the Wind's 100 most influential female power-brokers, deal-makers and influencers in A Word about Wind 2017 report. In 2015, the Recharge magazine has proclaimed Bartosik as one of the 40 under 40, in acknowledgement of her key contribution in driving WindEurope's successful operations, and a celebration of the decade of outstanding commitment to the development of the wind industry in Europe.

Since March 2020, Malgosia co-ordinates the activities of the RE-Source Platform. The Platform raises awareness on the advantages of renewable electricity sourcing and advocates for the right EU and national energy market legislation to boost green electricity procurement.

She is also Board member of the Global Wind Energy Council and OffshoreWind4Kids, a new initiative aiming at offshore education for children.

Bartosik is a regular speaker at various meeting industry events, advising associations executives and events' planners on creative marketing, crisis management and communication strategies. She is one of the city of Brussels Ambassadors, actively engaged in promotional activities of Europe's capital.