Financial infrastructure designed for the builders

Vertical: Technology

Mercury products: Treasury, IO, Invoicing, Payroll, Quickbooks integration, Bill Pay, Reimbursements

Founded in 2025 and headquartered in San Francisco, Sazabi is building the observability platform for engineering teams whose codebases now include collaborators that don't sleep. The product treats AI behavior as a new class of telemetry, ingesting logs autonomously and letting engineers root-cause issues through a natural-language interface rather than hours inside a dashboard.

For most of the last decade, Sherwood Callaway spent his days making sure other engineers never had to think about him.

At Brex, he helped start the Infrastructure and Observability teams — the kind of work measured in alerts that never fire, dashboards no one needs to check, and outages that don't happen. By the time he started Sazabi in 2025, he'd developed a particular reflex for how scaling systems break: the small assumption that holds fine at ten users and gives out at ten thousand.

That reflex carried into the company he founded. Sazabi is building for engineers whose work has changed shape — codebases that now include collaborators producing thousands of lines a day, often into systems no human reviewed line by line before they shipped. The observability stack built for hand-written code wasn't designed for what that produces downstream, and Callaway's thesis isn't a faster dashboard. It's a different interface: engineers ask a question in plain English, and the system returns a root cause. In short: logs as the Occam's razor of observability, with AI doing the work of pulling answers from them.

That same approach shaped how he picked a finance stack for the business, and why.

The phrase is a useful frame for a company built by someone who spent a decade evaluating platforms for a living. He wasn't looking for a single feature to clinch the decision. He was looking for the cumulative signal — small choices, made well, that add up to something he'd trust without thinking about it.

Spend works the way engineering does at Sazabi: rather than queueing against a single corporate card, the team issues virtual credit cards per vendor and spending category, with merchant categories and limits set at provisioning. New ad platform access for a campaign, a SaaS subscription tied to a specific tool, a one-off vendor seat — each gets its own card, and each closes when the use case closes. Spend rolls up without anyone having to reconstruct what came from where.

Idle cash earns , in lower-risk, high-liquidity portfolios that don't require active management. Auto-transfer rules move balances between checking and on a schedule. Payroll runs from the operating account directly — no out to a third-party processor, no separate reconciliation surface.

Recurring vendor payments and one-off transfers move through Bill Pay, with the same approval and audit trail as everything else and, as Sazabi moves from early-access engagements toward paying customers, Invoicing handles billing from inside the same platform that already handles cards, payroll, and reconciliation. Nothing new to bolt on when the revenue starts moving.

For a lean team, 'financial state' isn't something to reconstruct at the end of the month. With Mercury's Quickbooks integration, accounting runs in parallel with Sazabi's day-to-day operations. Transactions, bills, memos, and vendor tags move into the ledger, so up-to-date bookkeeping becomes the default.

Callaway's team is efficient and technically ambitious — the kind of operation that, by most playbooks, would already be carrying a few specialized finance tools and a part-time bookkeeper. It has neither. From a single platform, Sazabi manages:

• Credit cards with merchant-locked limits tracked at the moment of authorization
• Treasury yield on idle cash, with auto-transfer rules moving balances on schedule
• Bill Pay, Invoicing, and Payroll, processed and reconciled inside one system
• QuickBooks sync, keeping finances current without manual intervention

Callaway spent a decade evaluating platforms for a living. The one he picked for his own company doesn't ask for a second look.