Senior Fullstack Engineer

Meet Siena

Siena is the first intelligence layer for customer experience. Were creating an operating system of AI agents that learn remember and act across every customer touchpointfrom support conversations to shopping experiences to voice and social media interactions.

Siena doesnt just automate support; it powers shopping agents builds persistent customer memory generates actionable business insights and creates empathetic interactions that feel human.

Were transforming how businesses understand and connect with their customers turning every interaction into intelligence that makes the next one better.

The team

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

If youre excited about building something that doesnt exist yet keep reading. Were building agents that dont just respond to customersthey remember them learn from every interaction and connect experiences across channels.

About the Role

As a Full Stack Engineer at Siena youll own projects end-to-end developing and optimizing features within our AI-powered customer support automation platform. Youll work closely with product and engineering teams shaping our roadmap while building reliable high-performance systems. This role is for engineers who love solving real-world problems thrive in fast-moving environments and take pride in shipping great products.

What Youll Do

• 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.

Who You Are

• 7 years of software engineering experience in 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 mindsetyou think beyond just code and care about business impact.

• Deep experience in microservices architectures and scalable systems.

Bonus Points

• Experience with and LLM integrations.

• Infrastructure as Code (CDK Terraform).

• Python programming skills.

• Event-driven architecture experience.

• Background in customer support software.

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 youre 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. Were 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. Theyre direct about feedbackboth giving and receiving itbecause they care more about getting things right than being polite.

They maintain high standards while moving at startup speed and they build real relationships with teammates because they know thats how great work gets done. When things get tough they adapt and keep pushing forward.

Our approach to AI

The people who thrive here treat AI like a natural extension of themselves. Theyve 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.

Everyone gets premium accounts (ChatGPT Claude Perplexity Pro Cursor Lovable) plus a quarterly budget for new tools. But the magic happens in how we share knowledge. Demo days where someone shows off a clever workflows. Slack threads about which model handles a specific use case better. Learning from each others AI workflows.

At Siena were not just looking for people who can do a job. Were looking for people who want to break boundaries create the future and reshape industries. If thats you we look forward to your application.

We use AI-assisted screening tools as part of our hiring process. All decisions are made by humans. You can request a human-only review at .

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.

Required Experience:

Senior IC