Senior Full-Stack Developer – Node.js/React

S I Systems; Toronto; On-site; CAD 90,000 - 130,000; Full time

Job summary

S I Systems in Toronto seeks a Senior Full-Stack Developer to join a collaborative product engineering team. This hands-on role leads technical initiatives, mentors developers and provides direction when requirements are not defined.

The successful candidate will contribute to both new application development and ongoing platform improvements while solving a range of technical and product challenges, from backend APIs to modern React-based front-ends.

Qualifications

• Experience building modern web apps with React.
• Strong AWS and cloud-native development knowledge.
• Infra-as-code experience with Terraform.
• Experience with messaging queues or event-driven architectures.
• Proven ability to lead technical projects as an individual contributor.
• Experience mentoring junior/intermediate developers.
• Strong problem-solving and ambiguity management.

Responsibilities

• Lead technical initiatives from small improvements to cross-functional projects.
• Design and develop scalable backend APIs using JavaScript/Node.js.
• Build modern, responsive web applications with React.
• Mentor junior/intermediate developers.
• Define technical direction and drive delivery from concept to completion.
• Collaborate with product, engineering, and stakeholders.
• Support infrastructure-as-code and cloud-based practices.
• Contribute to event-driven and messaging-based architectures.
• Identify opportunities to improve performance, reliability, and developer experience.

Skills

JavaScript

Node.js

React

AWS

Terraform

Event-driven architectures

Mentoring

Problem solving

Ambiguity handling

Tools

Terraform

CI/CD

Docker

Messaging queues

Job description

We are seeking a Senior Full-Stack Developer to join a collaborative and innovative product engineering team. This is a hands-on individual contributor role for someone comfortable leading technical initiatives, mentoring developers and providing direction in situations where requirements may not be fully defined.

The successful candidate will contribute to both new application development and ongoing platform improvements while helping the team solve a variety of technical and product challenges.

Key Responsibilities

• Lead technical initiatives ranging from smaller improvements to larger, cross-functional projects
• Build modern, responsive web applications using React
• Mentor junior and intermediate developers
• Help establish technical direction and challenge existing approaches when appropriate
• Work through ambiguity and take ownership of solutions from concept through delivery
• Collaborate with product, engineering and other stakeholders
• Support infrastructure-as-code and cloud-based development practices
• Contribute to event-driven systems and messaging-based architectures
• Continue identifying opportunities to improve performance, reliability and developer experience

Must-Have Qualifications

• Experience developing modern web applications with React
• Solid understanding of AWS and cloud-native application development
• Experience with infrastructure as code, preferably Terraform
• Experience working with messaging queues or event-driven architectures
• Demonstrated ability to lead technical projects as an individual contributor
• Experience mentoring or supporting the development of junior and intermediate team members
• Strong problem-solving skills and the ability to work effectively through ambiguity

Nice-to-Have Experience

• TypeScript
• Styled Components or similar frontend styling frameworks
• Containerization technologies such as Docker
• CI/CD pipelines and automated testing
• Experience working in product-focused or financial technology environments

We are seeking a Senior Full-Stack Developer to join a collaborative and innovative product engineering team. This is a hands-on individual contributor role for someone comfortable leading technical initiatives, mentoring developers and providing direction in situations where requirements may not be fully defined.

The successful candidate will contribute to both new application development and ongoing platform improvements while helping the team solve a variety of technical and product challenges.

Key Responsibilities

• Lead technical initiatives ranging from smaller improvements to larger, cross-functional projects
• Design and develop scalable backend APIs using JavaScript and Node.js
• Build modern, responsive web applications using React
• Mentor junior and intermediate developers
• Help establish technical direction and challenge existing approaches when appropriate
• Work through ambiguity and take ownership of solutions from concept through delivery
• Collaborate with product, engineering and other stakeholders
• Support infrastructure-as-code and cloud-based development practices
• Contribute to event-driven systems and messaging-based architectures
• Continue identifying opportunities to improve performance, reliability and developer experience

Must-Have Qualifications

• Strong JavaScript and Node.js experience, particularly building backend APIs
• Experience developing modern web applications with React
• Solid understanding of AWS and cloud-native application development
• Experience with infrastructure as code, preferably Terraform
• Experience working with messaging queues or event-driven architectures
• Demonstrated ability to lead technical projects as an individual contributor
• Experience mentoring or supporting the development of junior and intermediate team members
• Strong problem-solving skills and the ability to work effectively through ambiguity

Nice-to-Have Experience

• TypeScript
• Styled Components or similar frontend styling frameworks
• Containerization technologies such as Docker
• CI/CD pipelines and automated testing
• Experience working in product-focused or financial technology environments

Disclaimer:

AI may be used in evaluating candidates.

This posting is for an existing vacancy.