Sphere Scales AI Tax Compliance Engine Following $21 Million Series A

Cross-border tax compliance remains a primary operational headache for software companies expanding internationally. Sphere, founded in 2022 out of Y Combinator’s W22 batch, is addressing this by building an AI-powered compliance platform that automates sales tax, value-added tax (VAT), and goods and services tax (GST) obligations. The company serves enterprise customers including Eleven Labs, Replit, and Windsurf, operating out of headquarters in San Francisco with a team of 28 employees.

According to reporting from TechCrunch and Pulse 2.0, Andreessen Horowitz led a $21 million Series A round into Sphere to expand its automated platform. The round included participation from Felicis, Uncommon Capital, and angel investors who founded companies including Go1, Lyft, BetterUp, Xendit, and Flexport.

Building Local Tax Rails and Specialized LLMs

Sphere’s platform handles four operational tasks: monitoring indirect tax exposure, registering businesses with government tax bodies, calculating and collecting accurate taxes directly inside customer billing systems, and filing returns to authorities.

To power these workflows, the engineering team spent 18 months establishing direct software integrations into tax authorities across both the United States and international markets. The platform runs on a Django and Python backend paired with a Next.js and React frontend.

Alongside direct tax integrations, Sphere uses specialized large language models and web data extraction pipelines to collect, parse, and monitor changing tax legislation and rate changes across global jurisdictions. This regulatory data is structured and pushed into Sphere’s core web application and exposed to client systems via API. The company intends to use this infrastructure as the foundation for a broad international billing and compliance system.

Team and Leadership

Sphere is led by co-founder and CEO Nicholas Rudder, an Australian native who relocated from Sydney to San Francisco. Rudder brings a background in technology and finance, including past experience at Macquarie, covered by AFR and The Australian.

The founding team also includes Arnold Lee, Luigi Charles, and Adrian Sarstedt. Charles studied Computer Science and Mathematics at Columbia University from 2015 to 2019 and previously scaled stablecoin payments infrastructure before co-founding Thesis Labs and robotics startup Darwin. Sarstedt is based in Germany.

Hiring Push Across Engineering, Compliance, and Sales

Sphere currently lists 16 open positions across technical development, localized tax operations, and go-to-market teams.

The technical team is making senior hires at its San Francisco headquarters. The company is actively recruiting an AI Agent Infrastructure Lead ($220,000 to $280,000 USD per year) to manage agentic pipelines, alongside a Lead AI Engineer ($250,000 to $280,000 USD per year) focused on the core tax extraction architecture. Core software development is expanding via a Senior Backend Engineer (Infrastructure) and a Senior Product Engineer.

On the domain side, Sphere is building dedicated regulatory leadership with remote roles including an E-Invoicing Lead and a Salt Lead in the United States, as well as TRAM Trainers in both the US and Europe to manage compliance workflows.

The commercial team is expanding in parallel to capture software clients across continents. Post-Series A go-to-market roles include an Account Executive (Europe) ($220,000 to $260,000 USD per year), an onsite Account Executive (SF) ($220,000 to $260,000 USD per year), and an onsite Sales Development Representative ($75,000 to $140,000 USD per year).

Open Positions at Sphere

See all open roles at Sphere