Finix, a startup that provides payments-related services to other companies, announced it has extended its Series B financing with a $30 million investment led by Lightspeed Venture Partners and American Express Ventures. The fintech startup has now raised over $96 million in venture capital. According to CEO and co-founder Richie Serna, $90 million of that total was grabbed in the last year alone. Finix declined to disclose its revenue, revenue growth, new valuation, current profitability, or number of customers in an interview with TechCrunch. Serna was willing to disclose that…