Jayasekera while contemporaries in school included Richard de Zoysa, Chanaka Amaratunga, Uthum Herat, Saliya Ahangama, Guy de Alwis, Devaka Fernando Palitha Kohona, Mendaka Samarasinghe and PL Munasinghe.
He held this position as chief executive officer of the SEC while as director general of the SEC, he held positions as a member of the Public Enterprises Reform Commission of Sri Lanka and the Sri Lanka Accounting and Auditing Standards Board.
Wikramanayake contributes to national bodies through service in committees for formulating codes on corporate governance established by the Institute of Chartered Accountants of Sri Lanka, the Securities and Exchange Commission of Sri Lanka and committees on corporate law appointed by the Government of Sri Lanka and the National Review Committee, to which he was appointed by the Ministry of Finance to review performance of State owned enterprises.
In 2009, Wikramanayake was appointed by the Central Bank of Sri Lanka to a four-member expert panel to advise financial institutions on making use of a stimulus package offered by the Government of Sri Lanka to overcome the effects of the financial crisis.
His publications include Butterflies of Sri Lanka (co authored with his daughter, Ariesha Wikramanayake) and Wildflowers of Sri Lanka,[10] continuing an association (comparable to that with the law and S. Thomas' College, Mt Lavinia) lasting 3 generations [11] or more (his grandfather E. B. Wikramanayake founder president of the Wildlife Protection Society of Sri Lanka[12] and also served as a member of the S. Thomas' College, Mt Lavinia board of governors).