Fullstack Software Engineer

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Meet Siena
Siena is the first intelligence layer for customer experience. We're creating 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.

The team
We're a small, distributed team that punches way above our weight. Every person here has outsized impact because we've built leverage into everything we do. This philosophy makes us faster and, frankly, more fun to work with.

About The Role
As a fullstack engineer at Siena, you’ll own projects end-to-end, developing and optimizing features within our AI-powered customer support automation platform. You’ll work closely with product, shaping our roadmap while building reliable, high-performance systems. Your code will power millions of monthly customer interactions across global brands, where reliability and speed directly impact business outcomes.

What You’ll Do

• Design, build, and maintain scalable features across the full stack (frontend, backend, and infra).
• Collaborate with Product to break down scope into iterative, high-impact releases.
• Integrate cutting-edge LLM capabilities into real enterprise workflows.
• 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.
• Exercise high agency and ownership—taking initiative, making decisions, and driving ideas to production.

Who You Are

• 3+ years building in Node.js, React, TypeScript, and Express.
• Strong with PostgreSQL, Redis, and cloud environments (AWS: Fargate, Lambda, EC2, SQS).
• Familiar with CI/CD (CodePipeline, GitHub Actions, or similar).
• Experience with microservices and scalable systems.
• Product-driven—you care about the impact of what you ship, not just the code.
• AI-first—you live in Cursor, Claude Code and are comfortable orchestrating coding agents.
• Naturally curious and proactive; you don’t wait for instructions, you create momentum.

Bonus points

• Next.js, Python, or event-driven architectures.
• Infra-as-code (Terraform, CDK).
• Experience integrating with LLMs in production.
• Event-driven architecture experience.

Why Siena?

• 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.

Our values
The people who thrive here are curious, customer-obsessed, and take ownership without being asked. They fix problems first and explain later. They're direct about feedback—both giving and receiving it—because they care more about getting things right than being polite.

Our approach to AI
The people who thrive here treat AI like a natural extension of themselves. They've built their own ecosystem of agents - some for research, others for debugging, writing, analysis, or writing code. They know which AI works best for what problem.

Siena provides equal employment opportunities to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability, genetics, sexual orientation, gender identity, or gender expression. We are committed to a diverse and inclusive workforce and welcome people from all backgrounds, experiences, perspectives, and abilities.