Senior Software Engineer

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.