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Is this position remote?

This role is based in Bucharest, Argentina, Berlin, Brazil, Cluj, London, Toronto, Warsaw. Check the full description for remote or hybrid options.

This position was posted 3 days ago. We recommend applying promptly as positions can fill quickly.

Siena is the first intelligence layer for customer experience, building an operating system of AI agents that learn, remember, and act across every customer touchpoint—from support conversations to shopping experiences to voice and social media interactions. Siena doesn't just automate support; it powers shopping agents, builds persistent customer memory, generates actionable business insights, and creates empathetic interactions that feel human. The company transforms customer connections, turning interactions into intelligence. The team is small, distributed, and highly impactful, focusing on building new AI agents that remember customers, learn from interactions, and connect experiences across channels.
As a Full Stack Engineer at Siena, you will own projects end-to-end, developing and optimizing features within the AI-powered customer support automation platform. This involves close collaboration with product and engineering teams, shaping the roadmap, and building reliable, high-performance systems. The role is suited for engineers who enjoy solving real-world problems, thrive in fast-moving environments, and are proud to ship great products, integrating cutting-edge LLM capabilities into enterprise customer support workflows.

Design, build, and maintain scalable features across the full stack (frontend, backend, and infrastructure).
Collaborate closely with Product to break down scope and deliver in iterative, high-impact releases.
Work on an AI-first product, integrating cutting-edge LLM capabilities into enterprise customer support workflows.
Solve complex engineering challenges, from optimizing API performance to refining microservices architecture.
Maintain and improve our cloud infrastructure (AWS) with a DevOps mindset.
Share knowledge and mentor teammates, fostering a strong engineering culture.

5+ years of software engineering experience in Node.js, React, TypeScript, and Express.
Solid experience with cloud environments (AWS – Fargate, Lambda, EC2, SQS).
Strong database skills with PostgreSQL and Redis.
Familiarity with CI/CD pipelines (CodePipeline, GitHub Actions, or similar).
Product-focused mindset—you think beyond just code and care about business impact.
Deep experience in microservices architectures and scalable systems.

Meaningful impact. Your work directly shapes our product and company.
Globally distributed team working at the bleeding edge of CX and AI.
Great salary plus the opportunity for equity or stock grants.
Learning budget. If you're growing, so are we.
The thrill of building something new. Join us at a stage where your contributions matter most.
AI-fluency. Make AI your second nature.
Tackle unsolved problems. We’re redefining how customer experience will look like in the next decades.
Everyone gets premium accounts (ChatGPT, Claude, Perplexity Pro, Cursor, Lovable) plus a quarterly budget for new tools.