A1 is building a proactive AI chat app for everyday users to bring intelligence to conversations, errands, organising and workflows. Unlike traditional chat‑based applications, our product focuses on achieving high reliability for long‑running workflows, persistent context, and real‑world task completion. The system must handle multi‑step reasoning, interact with external tools, and remain reliable despite non‑deterministic model behaviour. As a Backend Engineer, AI, you own the inference and orchestration layer that powers every AI interaction in the product. Your work sits between models and users, where latency, correctness, reliability, and cost directly impact real‑world experience. You will build and operate production systems that turn model capability into fast, stable, observable APIs used across mobile and desktop clients.