In 2011, Wasilewska joined the European External Action Service, heading Division for Conflict Prevention, Peace Building and Mediation Instruments,[4] and Division for Election Observation and Democracy Support.[5] In September 2016 she was appointed EU ambassador to Jamaica, accredited to Belize, Bahamas, Turks and Caicos Islands and the Cayman Islands, as well.[6]
Her term ended in August 2020[7] and by the end of 2020 she was appointed EU ambassador to the Barbados, the Eastern Caribbean states, the OECS and Caricom/Cariforum.[8]
Wasilewska specializes in conflict-sensitive development, post-conflict democracy building, and nonproliferation of small arms and light weapons.[3]