Speaking after his company posted strong half year results with revenues, profits and staff numbers all up, Clarke said there were good opportunities to be had in the next six to 12 months.
"There are good careers to be had and good projects to be involved in.We are not a boom, but the technical challenges are going to get harder, which is good for a company like us."
Clarke said business secretary Lord Mandelson was "dead right" when telling the CBI on Monday that now is a good time to be an engineer.
"Industry today is not about mills and smokestacks," said Mandelson. "It is about the next industrial revolution and the low-carbon or post-carbon technologies that will define the 21st century. If you really want to change the world, choose a career in engineering."
Clarke said staff numbers were unlikely to increase as much as of the last six months, but that recruitment was continuing.
"We have not got a recruitment freeze," he said.
Recruitment, he said, was likely to focus on specialist skills. "We have been hiring building physicists into the Middle East for carbon reduction, and have just bought MG Bennett and Associates for their nuclear expertise."
Clarke the company was well prepared for the current economic climate.
"The storm started some time ago. Cut-backs were evident six months ago. The lack of finance for PFI happened over a year ago. The banking crisis started 18 months ago. It is very important to put things in that context that is why we have positioned the company where we have and focused on where business is good. And it is paying off, and we are where we are.
"We remain confident of our outlook for the rest of the year. In the next six months to a year we will see quite strong perservations – short term delays, then accelerations, then delays. The signs are there that some clients wish to accelerate expenditure – which was well trailed ahead of Darling's speech on Monday. People are already saying to us "have you got the resources to accelerate design?
"As a result we will have to be quite agile between clients as they programme forward and backwards. But there are good opportunities and it is a time to be very confident."