Founding Engineer - Abacus

About AbacusAbacus is reinventing how accounting firms operate by building AI agents that automate the tedious, repetitive workflows that teams currently face. Our core engine combines advanced OCR and LLMs to deliver truly intelligent back-office automation. We're already working with large enterprise clients, generating meaningful revenue, and backed by top-tier investors. We've accomplished all of this as a team of two, and we're excited to grow our team. If you want to shape the future of AI-powered operations and own meaningful technical work from day one, this is the place.The RoleWe're hiring our first Founding Engineer to own and expand the core machine learning engine behind Abacus. You'll report directly to the co-founders and work in person from our SF office. This is a rare opportunity to join a high-growth company as an early engineer with massive autonomy and influence over product and technical direction.In your first 3-6 months, you'll:Improve and scale our ML extraction engine using LLMs and OCROwn backend architecture and infrastructure decisionsBuild and ship greenfield features to expand the workflows we automateOver the next year, you'll help lay the groundwork for our engineering org as we scale, while staying hands-on and focused on impact.What You'll DoLead development of our ML-powered document extraction engineArchitect backend systems with performance and scalability in mindBuild and deploy new automation features for tax firmsCollaborate closely with the founders on product and user needsHelp define our engineering culture and technical roadmapWhat We're Looking ForMust-haves:1-5 years of experience, ideally in high-ownership or early-stage environmentsStrong backend development skills, particularly in PythonProven 0→1 builder (side projects, startup experience, or both)Willingness to work from our SF office, 5 days/weekWillingness to complete a technical take-home exercise as part of the processNice-to-haves:Experience with LLMs, OCR, or data extraction systemsExposure to AI infrastructure or evaluation frameworksWhy Join UsNo ceiling on ownership or growthSignificant equity and high-leverage role at a fast-growing startupTop-tier health insurance, daily lunches, and an in-office baristaYou'll help define the trajectory of the product, team, and company!