Senior Backend Developer

Senior Backend Developer
Company: ViafouraLocation: Toronto / Remote (Canada)Employment Type: Full-timeSalary Range: $135,000 – $165,000 CAD annually

About Viafoura
Viafoura is a technology software company headquartered in Toronto. Our CommunityOS platform helps media brands build direct audience relationships: boosting registrations, engagement, and revenue on owned platforms. Our platform is accessed by nearly 1 billion monthly users and is deeply integrated into our customers’ CMS, identity management, and DMPs/CDPs to provide a seamless user experience.

About the Role
As a Senior Backend Developer, you’ll own significant pieces of the platform end-to-end: real-time engagement services (conversations, live chat, moderation), identity and audience systems, and the event pipelines that connect them — systems that serve production traffic at the scale of hundreds of millions of monthly users. You’ll design, build, and operate what you ship, working closely with your Team Lead and the Product team to deliver new capabilities for our clients while raising the engineering bar across the team.Our backend is built on Vert.x — an event-loop, non-blocking runtime. If your Java experience is exclusively Spring MVC-style thread-per-request development, expect a significant (and rewarding) shift.
Key ResponsibilitiesArchitecture & Systems Design

• Architect and implement highly scalable, distributed microservices-based applications.
• Design resilient, event-driven architectures and API contracts that support high-volume real-time data processing.
• Drive technical decision-making for long-term system maintainability, scalability, and performance optimization.

Backend Development (Java & Microservices)

• Design, develop, and maintain robust microservices using Java on non-blocking frameworks (Vert.x).
• Implement efficient code patterns, conducting thorough code reviews to ensure quality and adherence to best practices.

Data Engineering & Storage

• Architect and optimize high-performance data storage solutions, including MySQL, OpenSearch, and other NoSQL stores and caches.
• Build and maintain reliable pub/sub messaging systems and real-time data pipelines (Apache Kafka).
• Plan and execute complex, zero-downtime data migrations — evolving schemas and moving live data (dual-write, backfill, cutover) while systems serve production traffic.
• Optimize database performance, query efficiency, and complex data models.

Leadership & Delivery

• Own projects end-to-end: write the design doc, defend it in review, lead implementation across multiple engineers, and carry it through production rollout and post-launch operation.
• Collaborate with product and cross-functional teams to define service boundaries and deliver new capabilities.
• Mentor junior developers and lead initiatives that improve engineering processes and team excellence.
• Participate in our on-call rotation (currently one week on, three weeks off) and troubleshoot production issues to maintain system reliability.

Required Qualifications

• 5+ years of senior backend development experience in Java, including work across more than one framework or runtime model — e.g., non-blocking/reactive stacks (Vert.x, Netty, RxJava) — not solely Spring Boot.
• Strong JVM fundamentals independent of any framework: concurrency and threading models, event loops vs. thread-per-request, memory and GC behaviour under load.
• Track record as the technical owner of a project end-to-end — from design doc through production rollout — and the accountable engineer when things went wrong: incidents, rollbacks, postmortems on systems you designed.
• Proven experience building and scaling high-volume microservices architectures.
• Expertise in event-driven design using Apache Kafka for high-throughput data streams.
• Strong command of SQL (MySQL) and NoSQL database design, query optimization, and performance tuning.
• Proficiency in containerization (Docker) and orchestration (Kubernetes) within distributed environments.
• Experience with modern CI/CD pipelines, observability (logging/monitoring), and debugging in production.

Nice to Have

• Hands-on experience with a full datastore migration — schema and live data both moved, with a zero-downtime cutover.
• Proficiency in additional languages (Rust, Go, Node.js).
• Deep knowledge of cloud-native development (AWS) and Infrastructure as Code.
• Experience with alternative messaging platforms (SQS, RabbitMQ).
• Background in performance engineering and automated testing.

What We Offer

• Comprehensive health benefits
• Professional development opportunities
• Remote-friendly work environment
• Collaborative and innovative team culture

To Apply: Please submit your resume. Links to GitHub repositories, live projects, or a portfolio are welcome but not required.
Viafoura is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. All qualified applicants will receive consideration for employment without regard to race, colour, religion, gender, gender identity, sexual orientation, age, or disability.
Accommodations are available on request for candidates taking part in all aspects of the selection process. If you require accommodation, please contact careers@viafoura.com.