Firstbase.io (YC W21) — The all-in-one startup operating system
Incorporation, compliance, bookkeeping, and taxes – all in one place.
Firstbase.io is a Y Combinator company in the Winter 2021 batch. Its directory entry describes it as: The all-in-one startup operating system. The founder listed is Mark Milastsivy (Founder) (Y Combinator directory entry, March 8, 2021).
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Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
Firstbase | Incorporation, compliance, bookkeeping, and taxes – all in one place.
Firstbase helps anyone to build a US business. Start a company, set up banking, payments, and payroll, and manage a business — online, from anywhere.
The title and description the site itself served, answering 200. Not a cached copy and not the company's directory entry — what was live when we asked.
Mark Milastsivy
Founder
Founder&CEO of Firstbase.io. Based in NYC.
Founders, titles and bios as the company published them. Photographs are our own copies of the ones on that record, so they do not break when the original link expires.
One of 158 companies held here in B2B › Operations.
No investor is drawn from a Form D — the form states how many invested and never who. The one investor on this graph is named because a batch has exactly one.
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Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
A Full Report on Firstbase.io: verified, sourced, every claim cited, ready in a few minutes. See pricing.
What the Full Report on Firstbase.io covers
The Short Answer
Which Company This Is
What They Do, And How The Money Works
Who Runs It, And How To Reach Them
The Money: Funding, Valuation, Runway
Who Pays Them, And Who They Are Up Against
Warning Bells
Sources
6 cited sources found
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