"We never had a policy that prevented us from re-employing former workers. But now we are putting a lot more emphasis on our re-hire policy. The bank's businesses are growing fast and we have a huge manpower requirement. We realised that a number of people, who have previously worked with us, want to join back. Hence, this programme has been introduced," Philip Mathew, chief people officer at HDFC Bank, told Business Standard.

The bank aims to re-hire as many as 3,000 former employees in next 12-18 months. Apart from using formal channels like staffing agencies, the bank is leveraging social networking sites (Facebook, LinkedIn, Twitter, etc.) to contact former employees with job offers. "It is a formal hiring campaign with some degree of informality," said a senior banker with HDFC Bank.

The lender believes that this strategy will not only help in improving employee productivity but will also inject fresh ideas to grow businesses profitably. Many of HDFC Bank's former employees work in different industries. If they join back they will be able to share their experience and introduce new ideas. At the same time, these workers are familiar with the culture, systems and processes of the bank.

"This will ensure best of both worlds. They know what to expect, how to deliver – hence the learning and unlearning curve for them will be much shorter. Also, their ideas and experience will help the bank," said the banker. Business heads of the bank have extended their support to this programme, he claimed.

Globally, management consulting firm McKinsey is believed to have pioneered the concept of 'alumni relations' or staying in touch with employees who have left the organisation. But in India such a practice is not common.

While re-hiring, however, the bank is not relaxing any of its standard assessment processes. "Even for former employees we are following a competitive process. We are identifying those who previously had a good track record with us and doing well in their new organisations. Then they go through the similar process that we follow while recruiting new employees," Mathew said.

He added that the bank has not abandoned its lateral hiring programme, which continues and is expected to complement the Khoj project.

Former employees are not necessarily being re-hired to do the same job that they were previously doing at HDFC Bank. Many of them have joined in new departments. Majority of former employees are currently being added in the branch banking business, where the manpower requirement is generally high.

HDFC Bank had 68,165 employees at the end of March, 2014.