Senior Engineer, Internal tools

About A1 There are over 5 billion users using basic applications today such email, notes, tasks that are not AI-native. Our mission is to build a proactive smart assistant for everyday users to bring intelligence to conversations, errands, organising and workflows, with minimal prompting. 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 behavior. Our objective is to help users complete tasks daily enjoyable with over ~90%* reduced time. Role You are the engineering backbone of the internal tools team. Building and maintaining the platforms that every team in the company relies on. Your work directly increases organizational efficiency and enables teams to move faster. You’ll own systems end-to-end, from scoping and architecture through production deployment and iteration, connecting multiple business systems into a seamless, reliable internal ecosystem. What You'll Do Build & Ship Design, build, and maintain internal platforms and tools that serve People, Finance, Ops, Sales, and Engineering teams. Own features end-to-end: requirements, architecture, implementation, testing, deployment, and monitoring. Write clean, well-tested, production-grade code. You hold yourself to the same bar as customer-facing products. Architecture & Integration Build API-first integrations across the internal ecosystem — connecting HRIS, CRM, finance platforms, knowledge management, and developer tools into a coherent stack. Design for reliability, performance, and scale — what you build today must hold as the company grows 5–10x. Eliminate data silos. Build clean data pipelines that maintain a single source of truth across systems. Own your services in production: monitoring, alerting, incident response, and post-mortems. AI & Automation Build AI/LLM-powered features into internal wo