Renault has announced that Nick Chester, the team's chassis technical director, has departed the French outfit in the midst of its major restructuring plan.
Chester first worked with Renault back in 2002 as a race engineer, and remained at Enstone over the years, including when the original team was acquired by Lotus.
The British engineer took over from James Allison as technical director at Lotus in 2013 and remained in place when Renault bought back its former team at the end of 2015.
"I have enjoyed 19 years in a team with great spirit and have worked with an incredibly loyal and talented group of people," commented Chester who has begun a period of gardening leave.
"I am looking forward to a new challenge and wish everybody in the team all the best for the future."
Renault has under-performed its expectations this season, failing to inch closer to the sport's Mercedes-Ferrari-Red Bull trio of front-runners and outpaced by engine customer McLaren.
The writing was perhaps on the wall for the 50-year-old Chester when Renault announced last month the arrival of former McLaren man Pat Fry, a nomination that followed that of former Williams engineer Dirk de Beer as Renault's head of aerodynamics.
"Nick has been a key part of Enstone for almost 20 years," said Renault F1 managing directir Cyril Abiteboul.
"His passion for the team has never wavered, despite experiencing some extremely challenging times.
"More recently, his commitment, technical insight and enthusiasm have inspired us to move from the back of the grid to the front of the midfield.
"We would like to sincerely thank Nick for everything and wish him every success in the next stage of his career."