Back End Developer

CirrusLabs; Toronto; On-site; CAD 120,000 - 170,000; Full time

Job summary

CirrusLabs in Downtown Toronto is seeking 10 Senior Python Backend Engineers to drive a critical platform modernization. You will design, build, and deploy robust microservices, focusing on high availability, security, and scalable RESTful APIs using Python.

You will work in an agile environment, collaborating with cross-functional teams to ensure low-latency systems and strong observability. This is an on-site, high-impact role with long-term extension potential based on performance.

Qualifications

• Bachelor's or Master's degree in Computer Science, Engineering, or a related field from a recognized Canadian university.
• 5 to 10+ years of professional software development experience with backend focus.
• Expert proficiency in Python (not data science or scripting).
• Extensive RESTful API design and OpenAPI/Swagger documentation.
• Strong Microservices and distributed systems design experience.
• Experience with SQL (PostgreSQL/MySQL) and NoSQL (DynamoDB/Cassandra/MongoDB).
• Hands-on cloud experience (AWS, Azure, or GCP).
• Solid Git, CI/CD pipelines, and modern ops practices.
• Excellent system design capabilities and trade-off articulation.

Responsibilities

• Architecture & Design: Design, develop, and deploy high-availability microservices and RESTful APIs using Python.
• System Development: Build and maintain scalable backend systems with high transaction volumes and low latency.
• Database Management: Design and optimize schemas for SQL and NoSQL databases.
• Cloud Infrastructure: Deploy and manage apps in public clouds using containers and orchestration.
• DevOps & CI/CD: Champion modern DevOps practices with CI/CD pipelines and IaC.
• Collaboration: Participate in design reviews, code reviews, and documentation with cross-functional teams.
• Observability: Implement monitoring, logging, and alerting for system health.

Skills

Python

Backend engineering

API design

Distributed systems

System design

CI/CD

Cloud fundamentals

Education

Bachelor's or Master's in CS

Tools

Docker

Kubernetes

AWS

Azure

GCP

OpenAPI/Swagger

PostgreSQL

MySQL

MongoDB

DynamoDB

Cassandra

Job description

Location: Downtown Toronto, ON (100% Onsite)

Contract Duration: Immediate start through December 2026 (High likelihood of extension based on performance)

Experience Level: 5-10+ Years

Interview Process: Mandatory In-Person Technical Interview in Downtown Toronto.

About the Role

We are seeking 10 highly skilled Senior Python Backend Engineers to join a critical platform modernization initiative. This is a high-impact role focused on building robust, scalable, and secure microservices that power core business operations. You will be working in a collaborative, agile environment to solve complex distributed-system challenges.

Core Responsibilities

• Architecture & Design: Design, develop, and deploy high-availability microservices and RESTful APIs using Python.
• System Development: Build and maintain scalable backend systems capable of handling high transaction volumes with low latency.
• Database Management: Design and optimize schemas for both relational (SQL) and non-relational (NoSQL) databases.
• Cloud Infrastructure: Deploy and manage applications within public cloud environments (AWS/Azure/GCP), utilizing containerization and orchestration tools.
• DevOps & CI/CD: Champion modern DevOps practices, implementing robust CI/CD pipelines and infrastructure-as-code.
• Collaboration: Participate in system design reviews, code reviews, and technical documentation. Collaborate effectively with cross-functional teams to ensure seamless integration.
• Observability: Implement monitoring, logging, and alerting solutions to ensure system health and performance.

Required Qualifications (Must-Haves)

• Education: Bachelor's or Master's degree in Computer Science, Engineering, or a related field from a recognized Canadian university or college.
• Experience: 5 to 10+ years of professional software development experience, with a strong focus on backend engineering.
• Programming: Expert proficiency in Python (not data science/scripting focused).
• API Development: Extensive experience designing and building RESTful APIs with JSON and documenting via OpenAPI/Swagger.
• Architecture: Strong background in Microservices and Distributed Systems design (event-driven architecture, messaging queues).
• Databases: Proven experience with both SQL (e.g., PostgreSQL, MySQL) and NoSQL (e.g., DynamoDB, Cassandra, MongoDB).
• Cloud: Hands-on experience with at least one major cloud provider (AWS, Azure, or GCP).
• DevOps: Solid understanding of Git, CI/CD pipelines, and modern operational practices.
• System Design: Excellent system design capabilities and the ability to articulate trade-offs.

Preferred Qualifications (Nice-to-Haves)

• Domain: Experience in the Financial Services, Payments, or Fintech sector.
• Containerization: Production experience with Docker and orchestration tools like Kubernetes (EKS/AKS/GKE).
• Security: Knowledge of security best practices, compliance standards, and IAM.
• Observability: Experience with tools like Datadog, Prometheus, Grafana, or ELK Stack.