Senior Full Stack Engineer

**Mission:** Sphere has built the world’s first AI-native tax engine that helps companies like Eleven Labs, Replit, Runway AI, Windsurf (+ many more) automate their sales tax, VAT and GST obligations: * We're growing rapidly (34%+ MoM revenue growth) and helping the fastest growing tech companies around the world including Eleven Labs, Replit, Windsurf, Fathom, Linktree, Photoroom, Sierra AI, Zed etc * We’ve spent the last 1.5 years building local rails into tax authorities in both the US and internationally to properly automate compliance processes (no other vendor has done this) * We're building the world's first AI-native tax engine (which will be the foundation for a broader cross border compliance platform; think Deel for international billing) * We're well funded by Felicis Ventures and YC Sphere is looking for a versatile full stack engineer who can jump on different mission critical areas to help accelerate its production - e.g. filing infrastructure, tax engine and new product areas (input tax, withholding tax, e-invoicing). These areas are key levers towards scaling Sphere and growing ARR, meaning that your work will have a direct impact on the growth of the business **Why this is a massive opportunity:** 🌍 Massive TAM: Every business around the world needs this. Compliance isn’t optional. 🌬️ Strong macro tailwinds: Businesses are expanding globally at a faster pace, while tax authorities are cracking down on cross-border compliance, driving urgent demand. ✨ AI advantage: Incumbents can’t scale beyond the U.S.; our AI-native tax engine can. 🔮 Product vision: Indirect tax is just the start; we’re building the Deel for international billing. **What you will do:** _Within weeks:_ * Ship features related to a key component of Sphere’s platform - e.g. filing infrastructure * Own and manage this key component, driving measurable outcomes * Work directly with customers like Eleven Labs, Replit and Windsurf to improve / optimize that key component of the platform (e.g. improve filing generation and submission speed \[x\]%) _Within months:_ * Develop expertise across other key components of Sphere’s platform - e.g. tax engine, new products - to manage and execute improvements in this area * Lead / mentor additional engineers in component areas that you have worked in **What’s important to us:** * The Dog: Grit > pedigree. * Ship fast: If it can be done today, do it today. * Self-starter: No hand-holding * Accountability: You’ll be held accountable to objective, measurable targets each month. * In-person: SF only. **Requirements:** * Strong experience in Python . Our core application backend and data pipeline services are built with Python and Django * While frontend / React may not be your primary focus, you’re not afraid to dive in when needed * Very strong attention to detail. When you work with numbers this is a non-negotiable - it’s not enough to be 99% right. _Nice to have:_ * Experience working with large volumes of transaction data. You’ll be getting very familiar with it! * Experience with Django or Python ORM