Principal Engineer

Jobtailor; Toronto; On-site; CAD 180,000 - 240,000; Full time

Job summary

Jobtailor is seeking a Senior Backend Architect to own the technical direction of a live, revenue-generating platform in Toronto. You will drive architecture evolution, ensure zero-downtime changes, and harden the system with tenant isolation and security.

You will scale throughput, establish SLOs, observability, and incident practices, and lead performance and capacity work ahead of demand. This role blends hands-on coding with founder-level ownership in a fast-paced, low-process environment.

Qualifications

• 10+ years building and operating cloud-native backend or platform systems.
• Owned the scaling of a production SaaS or data platform through rapid customer growth: hardening, re-architecture under load, and maturing an early product to enterprise grade.
• Deep hands-on experience with high-throughput distributed systems: event streaming or message queues, async processing, idempotency, retries, backpressure.
• Strong performance engineering: profiling, load testing, horizontal scaling, capacity planning.
• Production reliability ownership: observability, SLOs, incident management, fault-tolerant design.
• Multi-tenant SaaS experience, including tenant isolation and noisy-neighbor problems.
• Proficiency in Python and JavaScript/TypeScript (Next.js).
• Hands-on daily coder with founder-level ownership; comfortable in low-process, high-ambiguity environments.

Responsibilities

• Own technical direction and architecture evolution of a live, revenue-generating platform.
• Scale throughput and reliability while customers onboard, including zero-downtime changes to running systems.
• Harden the platform: tenant isolation, rate limiting, security, data integrity.
• Establish observability, SLOs, and incident practices as the customer base grows.
• Lead performance and capacity work ahead of demand, not behind it.
• Raise engineering standards through design reviews and mentorship.
• Partner with Product to balance platform investment against feature delivery.
• Identify and retire scaling risks and technical debt before they compound.

Skills

Cloud-Native Backend

Distributed Systems

Python

TypeScript

JavaScript

Observability

Tools

Kafka

ETL

API Platforms

Integration Platforms

AI/LLM-Driven Capabilities

Job description

• Own technical direction and architecture evolution of a live, revenue-generating platform
• Scale throughput and reliability while customers onboard, including zero-downtime changes to running systems
• Harden the platform: tenant isolation, rate limiting, security, data integrity
• Establish observability, SLOs, and incident practices as the customer base grows
• Lead performance and capacity work ahead of demand, not behind it
• Raise engineering standards through design reviews and mentorship
• Partner with Product to balance platform investment against feature delivery
• Identify and retire scaling risks and technical debt before they compound

Requirements

• 10+ years building and operating cloud-native backend or platform systems
• Owned the scaling of a production SaaS or data platform through rapid customer growth: hardening, re-architecture under load, and maturing an early product to enterprise grade
• Deep hands-on experience with high-throughput distributed systems: event streaming or message queues, async processing, idempotency, retries, backpressure
• Strong performance engineering: profiling, load testing, horizontal scaling, capacity planning
• Production reliability ownership: observability, SLOs, incident management, fault-tolerant design
• Multi-tenant SaaS experience, including tenant isolation and noisy-neighbor problems
• Proficiency in Python and JavaScript/TypeScript (Next.js)
• Hands-on daily coder with founder-level ownership; comfortable in low-process, high-ambiguity environments
• Built or scaled an integration platform, ETL/data pipeline product, or API platform (connectors, transformation pipelines, webhooks) (Nice to Have)
• Kafka or similar streaming infrastructure at scale (Nice to Have)
• Supply chain or logistics systems exposure (WMS, OMS, TMS, EDI integrations) (Nice to Have)
• AI-assisted engineering workflows; AI is deeply embedded in how we build (Nice to Have)
• Experience shipping AI/LLM-driven capabilities in production (rag, generation pipeline, agentic workflows) (Nice to Have)

Core Competencies

Demonstrates expertise in scaling cloud-native backend systems, ensuring production reliability, and implementing performance engineering practices. Proficient in Python and JavaScript/TypeScript, with a strong focus on multi-tenant SaaS architecture and observability.

Highest-signal resume keywords

• Cloud-Native Backend Systems
• Performance Engineering
• Production Reliability Ownership
• Multi-Tenant SaaS Experience
• High-Throughput Distributed Systems

ATS Optimization Keywords

Hard Skills

• Python
• JavaScript
• TypeScript
• Event Streaming
• Message Queues
• Async Processing
• Load Testing
• Capacity Planning
• Fault-Tolerant Design
• Tenant Isolation

Soft Skills

• Mentorship
• Leadership
• Collaboration

Industry Keywords

• SaaS
• Data Platform
• Observability
• Incident Management
• Scaling Risks
• Technical Debt

Tools & Technologies

• Kafka
• ETL
• API Platforms
• Integration Platforms
• AI/LLM-Driven Capabilities