About the Role At Arc , we are on a mission to amplify employees at local businesses using AI. With years of experience building and scaling commerce tools for businesses - from farmers markets and neighborhood coffee shops to global retailers, restaurant chains, and major sports venues - we know how to deliver mission‑critical technology that integrates easily, delights customers, and works every time. Voice drive-thru is our first product on that journey: an AI voice agent that takes real orders at the drive-thru speaker, in real time, integrating directly with a business's existing POS and hardware. Done well, this means more revenue, faster lines, and fewer mistakes for the operators we serve. As a Senior Software Engineer, you'll take ownership of the hardest technical problems across our stack including backend and AI systems: designing for reliability, speed and accuracy under live drive-thru traffic. This is a high-leverage, high-autonomy role for someone who wants to shape the technical direction of a fast-moving product, not just execute tickets. What You'll Do Design and evolve the core architecture of our conversational AI and voice-ordering systems, balancing latency, reliability, and correctness in a live, in-lane drive-thru environment Lead complex, cross-cutting technical initiatives - from POS and hardware integrations to evaluation and observability of AI agent behavior - that span multiple systems and teams Set technical direction and standards for the backend, and mentor and onboard new hires. Partner closely with product and operations to translate the real-world, on-the-ground needs of local business operators into robust technical solutions Improve how we test, evaluate, and monitor AI agent quality, given the unique challenges of validating non-deterministic, conversational systems Debug and resolve the gnarliest production issues, especially ones spanning real-time audio, third-party integrations, and distributed services What We're Looking For 5+ years of professional software engineering experience, with a track record of owning significant systems end-to-end Deep experience with backend systems in Python (or similarly strong general backend fundamentals with a willingness to go deep in Python) Experience designing for reliability and correctness in real-time or latency-sensitive systems Comfort operating with ambiguity - you can take a loosely defined problem and drive it to a well-architected solution Strong judgment about when to build for scale vs. when to move fast - and the communication skills to bring others along with your reasoning Bonus: experience with conversational AI/LLM-based systems, real-time audio/telephony platforms, or integrating with third-party/legacy POS or specialized hardware Why Join Us You'll have significant influence over both the product and the engineering culture at an early-stage company solving a genuinely hard, high-stakes problem: real-time AI that talks to real customers, in service of a mission to help local businesses run better. Voice drive-thru is just the beginning - your decisions will help shape what comes next.