Mercedes have underlined their determination to start winning in Formula 1 by signing two leading names to bolster their design team.
Former Ferrari technical director Aldo Costa joins as engineering director.
And Geoff Willis, who numbers Red Bull among his former teams, will become Mercedes' new technology director.
They will work under the team's technical director Bob Bell - himself a high-profile recruit from Renault earlier this year.
Mercedes have had a disappointing two seasons since they took over the 2009 world champions Brawn in time for the 2010 season.
Their best results are three podium finishes courtesy of Nico Rosberg, and this year they are fourth in the constructors' championship, and have been some way off the pace of the top three teams, Red Bull, McLaren and Ferrari.
BBC Sport understands that the team are under pressure to raise their performance level, and these high-profile appointments are a further signal of a drive to commit resources to strengthen their technical team.
Costa, who starts work on 1 December, was sacked from his role as Ferrari technical director in May after the team's disappointing start to the season, but he is well known to Mercedes team boss Ross Brawn, who previously worked with him at Ferrari.
Costa was a key member of the Ferrari design office under technical director Brawn and chief designer Rory Byrne when they were dominating F1 in the early 2000s with Michael Schumacher, who came out of retirement to drive for Mercedes in 2010.
Willis, who joins Mercedes on 17 October, has most recently been working with the struggling HRT team as a consultant. But - like Bell - he is one of the sport's most respected aerodynamicists.
 | Building a winning team is an exciting challenge for us - we are moving ourselves into the best possible position to achieve our ambitions Ross Brawn Mercedes team boss |
Prior to his position at HRT, Willis held a series of high-profile roles at Red Bull, under their current chief technical officer Adrian Newey, with whom he also worked at Williams during their successful years in the mid-1990s.
Willis was also technical director of the BAR and Honda teams in the early 2000s.
Mercedes said Costa would be responsible for design and development, while Willis would head aerodynamics, vehicle dynamics, control systems and simulation functions.
Brawn said: "Building a winning team is an exciting challenge for us all as we work towards the competitiveness and standards that we aspire to as the Mercedes-Benz works team.
"With a strong technical structure led by Bob Bell, we are moving ourselves into the best possible position to achieve our ambitions."
Other teams have spoken privately of Mercedes offering significant salaries to tempt engineers to join them.
But the team insist their recruitment drive will still keep them within the terms of the Resource Restriction Agreement, which limits staff numbers, research and development and external spend of F1 teams.
Mercedes vice-president of motorsport Norbert Haug added: "We have been putting in place the building blocks for success.
"Our technical organisation was strengthened by the arrival of Bob Bell and, working closely with Ross, he has identified the areas where we can improve still further.
"Aldo and Geoff will reinforce our technical management and bring the experience required to harness the talents of our people in [the team's headquarters at] Brackley; we have also recruited and invested at other levels in order to maximise our competitiveness under the Resource Restriction Agreement.
"Our goal remains to progress step by step in order to establish ourselves as a front-running team for the long term, in line with the tradition of the Mercedes-Benz Silver Arrows."
