Senior Fullstack Engineer

Siena AI; Toronto; Hybrid; CAD 80,000 - 120,000; Full time

Job summary

Join a forward-thinking startup on a mission to revolutionize customer experience through empathetic AI. As a Full Stack Engineer, you'll own projects end-to-end, developing features for an AI-powered customer support platform. This role offers the opportunity to work with cutting-edge technology and make a real impact in automating workflows. Collaborate with a dynamic team and embrace an AI-first philosophy that empowers creativity and innovation. If you're passionate about solving real-world problems and thrive in fast-paced environments, this is the perfect opportunity for you.

Benefits

Flexible time off

Learning budget

Competitive compensation

AI tool accounts

Remote work flexibility

Qualifications

• 7+ years of software engineering experience with a focus on full-stack development.
• Strong database skills, particularly with PostgreSQL and Redis.

Responsibilities

• Design and maintain scalable features across the full stack.
• Collaborate with Product to deliver high-impact releases.

Skills

Node.js

React

TypeScript

Express

PostgreSQL

Redis

CI/CD pipelines

microservices architecture

Education

Bachelor's degree in Computer Science or related field

Tools

AWS

Fargate

Lambda

EC2

SQS

Next.js

Terraform

Job description

About Siena

Siena is building enterprise empathic AI Agents powered by reasoning-adept LLMs. Siena is the first AI Agent of its kind, designed to integrate with existing systems and interact with customers across multiple channels from a single, unified platform.

If you're excited about the intersection of human-to-machine communication and want to be part of a team driving innovation and making a real impact in automating agentic workflows, join us on our mission to revolutionize customer experience through empathetic AI.

Our AI-First Philosophy

At Siena, AI isn't just a tool—it’s embedded in our DNA. We believe that leveraging AI-first workflows empowers individuals to work smarter, faster, and more creatively. Our team embraces AI-powered augmentation in everything we do, from research to execution, making us more efficient and innovative every day.

About the Role

As a Full Stack 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 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 You’ll 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 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.

Bonus Points

• Experience with Next.js and LLM integrations.

• Infrastructure as Code (CDK, Terraform).

• Python programming skills.

• Event-driven architecture experience.

• Background in customer support software.

Why Join Us

We’re a startup, so no fancy offices or corporate fluff. But here’s what we do offer:

• Make a real impact. Your work directly shapes our product and company.

• A voice that matters. In a small team, every perspective counts—yours included.

• Work your way. Whether it’s from home, a coffee shop, or a moon base—if you're productive, we’re happy.

• Competitive compensation. Great salary plus the opportunity for equity or stock grants.

• Flexible time off. Take at least 15 days—more if you need it.

• A 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.

• Tackling meaningful challenges. We’re redefining how work gets done through AI.

Our values

We’re not about corporate jargon—here’s what truly matters to us:

• Curiosity and creativity: You always seek new knowledge, ask questions, and explore different perspectives to deepen your understanding.

• Customer empathy: You are driven by our customers’ success. You see needs they can’t articulate.

• Resilience: You bounce back from setbacks, adapt to change, and thrive in the face of challenges.

• Ownership and autonomy: When things break, you fix first, explain later.

• Relationships: You create bonds with your colleagues - building trust and sharing success.

• Craft and speed: You balance vision with pragmatism. Your standards pull everyone higher.

• Open and direct: You share and receive feedback. You are open about what’s working and what not.

AI-First Tooling

To ensure you stay at the cutting edge of AI-driven work, we provide:

• Perplexity Pro account

• ChatGPT Pro account

• Claude Pro account

• Quarterly budget for experimenting with new AI tools

• A culture that encourages AI experimentation and adoption

We encourage our team to explore and integrate AI tools into their workflows, allowing them to maximize efficiency and innovation in their roles.

At Siena, we’re not just looking for people who can do a job. We’re looking for people who want to break boundaries, create the future, and reshape industries. If that’s you, we look forward to your application.

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.