One of the co-founders of Tyro Payments - its current head of sales, Andrew Rothwell - is to leave the organisation on 19 May "to pursue a new opportunity in a start-up technology business," the fintech announced yesterday. A new director of sales has been identified and an announcement is expected in coming weeks. Rothwell said Tyro has grown from a three-person start-up to over 400, and so he felt it was time for him to move on.This continues a degree of churn and expansion at the top of Australia's only tech firm to hold an unrestricted banking licence, backed by an injection in December 2015 of about $100 million in fresh growth equity capital, raised from Tiger Global in New York, TDM Asset Management in Australia, and Atlassian co-founder Mike Cannon-Brookes.It was believed to have been the largest private equity capital raise for a fintech business in Australian history, valuing the business at more than half a billion dollars.In October last year, Gerd Schenkel, a former Telstra Digital executive director and founder of NAB's digital banking start-up UBank, was appointed chief executive officer, with long-time CEO Jost Stollmann remaining with the company in a newly created executive director role.In January this year, former PayPal executive Kareem Al-Bassam was appointed Tyro's new head of product. Al-Bassam has more than 15 years of experience in the global payments industry.He founded PayPal Credit in Australia, with the launch of SMB Lending product, PayPal Working Capital.  In its first two years of operation, PayPal Working Capital originated more than $100 million in loans in Australia, according to his new employer, Tyro.Natalie Dinsdale, Tyro's new head of marketing, was also appointed in January. She has more than 17 years' experience as a marketer in entrepreneurial and challenger financial services challenger organisations in Australia and the UK, including Egg (UK's first online bank), Virgin Money, UBank and Bankwest.