Major banks are working hard to lock in the most promising fintech ventures that come their way, although hopeful start-ups have all too often been pushed back out the door by cultural mismatch.This was the conundrum discussed by a panel of big bank in-house venture capital managers at tech expo CeBIT, running in Sydney this week.A case in point: Todd Forest, managing director of NAB Ventures, said he and his team may field up to 1000 approaches each year. In his ideal world (and that of his risk averse big bank peers) onboarding a new fintech partner could involve up to 300 questions and other associated box ticking.In a more pragmatic world, a promising technology may slip through his fingers. To counter that, Forest said, NAB has developed a "junior version" of what is otherwise a very process-driven proof of concept exercise."The advantage is to recognise [the fintech is offering] something that the bank can't do" he said. One of the buzzwords thrown around in this and other panel sessions that followed was "adjacency" - that is, a non-competing but complementary area of the industry sector or wider economy.One example of this was proquo, initially set up as a market place for small business to business, as a joint investment with Telstra. Now both those giant companies are finding their creation works for themselves as well, if used as a procurement source for goods and services under A$75,000.Heath Brown, executive director of client experience and innovation at CBA Innovation Labs had a similar anecdote in regard to Airtasker. He admitted that his team, while in the development to proof of concept stage, intended it as an external identity management platform for service providers and consumer. But they realised it had wider application for the bank's main business. He also revealed that three years on, "finding these adjacencies is one area where our effort is going."However, the introduction and "onboarding" process needed to become more efficient, and also not to fail once inside the bank itself, Brown said. "We knew we had to improve the onboarding process for proof of concept. A risk person on our Sprint team is just as important as an engineer - in fact, looking at the risk of what can go wrong and mitigating that, it's the first box to tick before we even get to value proposition," he said.Katie Mihell, director of business development at Westpac agreed. "You can have a very enthusiastic business sponsor, but the stumbling blocks are where the various support areas have to come in and sign off: legal, insurance, information security group - know up front what the technology protocols are. It's the no 1 value add." "Risk - be aware of the risk environment. And there is finance: due diligence might kill a deal if the start-up looks like it'll run out of money before it's properly up and running," Mihell said.Michael O'Shea, head of customer led innovation at Bendigo and Adelaide Bank pointed to cultural mismatch as his