Sentio, a Seattle startup building a tool to help developers monitor different layers of their blockchain-based applications, announced a $6.4 million round led by Lightspeed Venture Partners. The company was co-founded last year by Fuyao Zhao and Chongzhe Li. The duo sold their last startup Insight.io to Dutch search giant Elastic in 2018. Sentio said it will use the funding to grow headcount from 10 to around 15-to-20 people by next year. Other participants in the round include Hashkey Capital, Canonical Crypto, Essence VC and GSR Ventures.