Crypto infrastructure company Alchemy said Thursday it raised $250 million in a Series C round led by Andreessen Horowitz (a16z), valuing the company at $3.5 billion and padding an already hefty venture war chest for building out crypto’s Web 3 stack.

“We actually haven’t touched any of the money” from Alchemy’s $80 million Series B announced in March, said co-founder Joe Lau, “because we’re profitable as a business.”

Alchemy, which provides developer services to decentralized finance (DeFi), non-fungible token (NFT) and other crypto projects, is fast becoming the blockchain world’s version of Amazon Web Services (AWS).

Alchemy’s behind-the-scenes positioning makes it one of the most prolific rails for crypto infrastructure, though most end-users are unfamiliar with the brand. It focuses on Ethereum, its layers 2s and the Flow blockchain but has plans to stretch further.

Read more: ‘AWS for Blockchains’ Alchemy Closes $80M Funding Round at $505M Valuation

Adding a big backer to Alchemy’s term sheet was as important as stocking extra cash, CEO Nikil Viswanathan said in an interview. Andreessen Horowitz (a16z) is one of crypto’s most active venture firms and invests in many of Alchemy’s clients.

“We power virtually every NFT [marketplace], we power the majority of DeFi, we power most of the top apps in this space,” Viswanathan said. “Working with a16z is just another extension for us, so that we can see all the early projects get onboarded.”

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Added early investor Paul Veradittakit of Pantera Capital, “Alchemy pioneered the core developer platform that supports the entire blockchain industry.”