Senior Backend Engineer - Java & Event-Driven Systems

MCD McKesson Canada Corporation / La Corporation McKesson Canada; Mississauga; On-site; CAD 90,000 - 130,000; Full time

Job summary

Purolator is seeking a backend-focused Java engineer to design and build high-volume services behind our logistics and tracking platform. You will own services end to end: design, implementation, tests, and deployment pipelines, with a focus on reliability and maintainability.

The role emphasizes deep server-side work over frontend tasks, with exposure to AWS, CI/CD, PostgreSQL, and event-driven systems. Strong testing habits, good design judgement, and collaboration on APIs across teams are

Qualifications

• Bachelor's degree in computer science or equivalent work experience.
• Experience with automated testing frameworks and a genuine habit of writing tests (JUnit).
• Strong SQL ability and hands-on PostgreSQL experience including schema design and tuning.
• Experience designing and building event-driven systems (message queues, event streams, async processing).

Responsibilities

• Design and build backend services in Java, with an emphasis on clean, maintainable architecture.
• Design and build event-driven services and the messaging/streaming flows that connect them.
• Write and maintain automated tests (unit, integration, and service-level) as part of your work.
• Apply established design patterns appropriately and know when not to reach for one.
• Work with AWS-hosted infrastructure and CI/CD pipelines to deliver changes safely and frequently.
• Model, query, and tune data in PostgreSQL with reasoning about the database.
• Collaborate on API design and contracts with other teams consuming your services.
• Support and operate the services you build by investigating production issues and maintaining health.

Skills

Java backend

JUnit testing

SQL PostgreSQL

Event-driven architecture

AWS

CI/CD

Performance & concurrency

Education

Bachelor’s degree in computer science or equivalent work experience

Tools

Terraform

Job description

Purolator is seeking a backend-focused Java engineer to design and build high-volume services behind our logistics and tracking platform. You will own services end to end: design, implementation, tests, and deployment pipelines, with a focus on reliability and maintainability.

The role emphasizes deep server-side work over frontend tasks, with exposure to AWS, CI/CD, PostgreSQL, and event-driven systems. Strong testing habits, good design judgement, and collaboration on APIs across teams are