Williams has announced that Rob Smedley, its Head of Performance Engineering, will depart the team at the end of the current season.
After a ten-year stint at Ferrari, Smedley joined Williams in 2014 to help guide the British outfit's race operations team at a time of transition following a poor campaign in 2013.
Williams went on to finish third in the Championship for two consecutive years before finishing fifth in 2016 and 2017.
"I have thoroughly enjoyed my time at Williams," commented Smedley.
"The team has been through great change since I joined in 2014 and it has been a pleasure to have played a part in that.
"Williams is a very special team within the F1 community and I’m certain that with all the talent that we have here they will go on and do better things.
"The team will always remain close to my heart. After 20 years in Formula One, however, I feel it’s the right time to reflect on things and evaluate what the next move is.
"I’m thoroughly looking forward to spending more time with my family before deciding on future opportunities."
Williams deputy team principal Claire Williams praised the 44-year-old engineer for his commitment and contribution over the years.
"It has been a pleasure having Rob in our team for the last four years and we will miss him both personally and professionally," said Williams.
"He agreed to join us at a time when our performance was low, and we are grateful that he saw the potential for us to turn things around at that time.
"During his time with us, he has made a significant contribution to the team through his role, but he’s also been just a great person to have at Grove, inspiring many with his enthusiasm and passion for Formula One.
"Rob’s been in the sport a long time, so we totally understand and respect his decision to take some well-deserved time out to spend with his wife and boys," she added.
"We wish him all the best and thank him wholeheartedly for the time, passion and fighting spirit he’s given to Williams."