Zak was appointed as assistant coach to the England and GB men's teams in July 2020 following a hugely successful spell in charge of the Welsh men's set up.
In 2019, he led them to retain their top flight EuroHockey Championship status for the first time in two decades as they finished sixth, their joint-highest placing at the tournament. He also led them on a rise in the world rankings from 36th to 18th and played a crucial role in the development of players such as Jacob Draper and Rupert Shipperley.
Having previously assisted the men's senior team and the GB Elite Development Programme on occasions, Zak also enjoyed a very fruitful spell in charge of Buckingham HC's women too, helping them earn promotion to the Women's Premier Division and appear in three consecutive League Finals weekends after winning five Conference West titles. However, perhaps most notably he took charge of the indoor team that won their first ever Super 6s title in 2020.