Staff Software Engineer

MEET SIENA Siena is the Agent of Record for consumer brands. One agent that owns the entire customer journey, running on a shared intelligence layer no point tool can replicate. Consumer brands run ten or more disconnected tools to manage their customers. We collapse that stack into a single agent. It started with support, the hardest surface a brand has, and it expands from there: Shopping Agent, Social Agent, Siena working alongside a brand's own operators. One agent across every surface, with shared memory, shared context, and shared tools. Hundreds of brands already run real customer volume on Siena in production. This is built, working, and growing, and we are racing to build what comes next. THE TEAM We are a small, fully distributed, global team. We have built leverage into how we work, which is what lets a team this size move at the speed we do. We hire athletes. Everyone here owns real outcomes, defaults to writing over meetings, communicates with directness, and acts the moment they see something worth acting on. Low ego, high standards, fast clock. If you want to own real problems rather than close tickets, keep reading. ABOUT THE ROLE This is a Staff-level role for an engineer who operates beyond their own projects. You will decide how core parts of the platform get built, raise the bar for the whole engineering team, and own the hardest technical problems we have. You will work across the full stack and the full lifecycle: setting architecture, making the cross-cutting calls, and making the engineers around you measurably better. You will partner directly with product and leadership to shape what we build and how we build it. High autonomy, high trust, high consequence. It is built for someone who wants exactly that. WHAT YOU'LL DO - Set technical direction and architecture for major areas of the platform, and bring the rest of engineering with you. - Own our hardest problems end to end: the ambiguous, cross-cutting, high-stakes work where the right path is not obvious yet. - Make the build/buy and architectural calls that shape the platform for years, and write down the reasoning so others can build on it. - Take cutting-edge language models into production inside enterprise customer workflows, where reliability and safety actually matter. - Multiply the team. Raise the engineering bar through design review, technical mentorship, and the standard you set by example. - Identify the technical initiatives we should be running, rather than waiting to be handed them. - Keep us honest on reliability, performance, and scale as we grow across channels and brands. WHO YOU ARE - You have operated at Staff level, or you are clearly ready to. You are the person other engineers turn to when a decision is hard. - 7+ years of software engineering, with a track record of technical leadership across teams or systems. Years are a floor, not the signal. - Deep full-stack strength in our core stack: Node.js, React, TypeScript, Express. - Strong with AWS in production (Fargate, Lambda, EC2, SQS) and with PostgreSQL and Redis. - Fluent in microservices and distributed systems, and clear on when not to reach for them. - Comfortable owning CI/CD and infrastructure with a real DevOps mindset (CodePipeline, GitHub Actions, or similar). - Product-minded. You think in customer outcomes and business impact, not tickets closed. - You have shipped LLM-powered features to production. This is a must, not a bonus. You know what breaks when models meet real users at scale. - Direct, low-ego, high-ownership. You fix first and explain after, and you give and take honest feedback without flinching. BONUS POINTS - Next.js. - Infrastructure as Code (CDK, Terraform). - Python. - Event-driven architecture. - Background in customer support or CX software. WHY SIENA? - Real ownership. You will own problems, not tasks, with the autonomy to solve them your way and the trust to do it without a manager in your inbox. - Work that ships and matters. What you bui