In addition to being an advocate, Madelaine holds a degree in civil engineering from the Technion, and previously served as city engineer in Petah Tikva for more than 10 years and as the manager of the building licensing department at the Bat Yam Municipality and as the regional director of the Building Licensing Department of the Tel Aviv Municipality.

Ongil has extensive experience in all aspects connected with planning and construction, giving legal and planning opinions, escorting town planning schemes and building licenses, TAMA/38, legal representation before the various planning authorities, lodging objection and appeals, filing administrative and High Court of Justice petitions, expropriations, betterment levies, Israel Land Authority and more.

Possesses experience in the registration of building contracting companies and in obtaining approvals for Palestinian workers.

Member of the property and real estate forum of the Israel Bar.

Heads the planning and construction department of the firm.