Top Software Engineer Jobs in Toronto

Build and operate reliable software that automates healthcare processes such as benefit verification and prior authorization. Lead complex product initiatives from discovery through launch, contributing across backend services, interfaces, data models, integrations, and AI-powered workflows. Own technical direction, architecture, testing, observability, safe rollouts, and shared services while partnering with Product, AI, Operations, and users. Mentor engineers and develop AI-native tools and processes.

Build scalable, low-latency backend APIs, event-driven services, model-serving layers, and integrations supporting real-time and batch personalization and recommendation experiences. Design reliable, secure, observable distributed systems using Java and Spring Boot, optimize performance and operational efficiency, and integrate LLM and AI services into production applications. Collaborate with engineering leadership and use AI-assisted development tools to improve delivery and code quality.

Designs and executes functional, integration, API, automated, exploratory, and end-to-end tests for personalization, recommendation, experimentation, and consumer intelligence capabilities. Builds test suites, validates AI-driven outputs and consumer journeys, manages test data, performs cross-browser testing, partners with engineering and product teams, and improves automation coverage, regression efficiency, and defect detection.

Evaluate AI coding agents such as Codex, Claude Code, and Cursor for engineering judgment, response quality, reasoning, usefulness, and trustworthiness. Provide clear written and recorded feedback, distinguish quality levels, and help define standards for excellent AI-assisted development workflows. This is a flexible, remote contract role focused on evaluation rather than production coding.

Design, develop, and maintain high-performance consumer-facing web applications using React, TypeScript, and JavaScript. Lead frontend architecture, performance optimization, accessibility, reusable component development, API integration, experimentation, production troubleshooting, and CI/CD support. Collaborate with Product, Design, QA, Platform, and Architecture teams while mentoring engineers, conducting code reviews, supporting Agile delivery, and improving engineering quality and operational excellence.

Build and operate backend systems, APIs, integrations, automation workflows, and enterprise knowledge infrastructure for AI applications. Develop retrieval pipelines, vector database solutions, and agent-based systems while improving scalability, observability, reliability, and performance. The role requires production software engineering, modern AI architecture knowledge, clear documentation, testing, and collaboration with technical and nontechnical teams.

Build and operate Origin’s AI observability platform across data-collection agents, backend services, infrastructure, inference pipelines, APIs, and React interfaces. Design distributed systems using AWS, EKS, ClickHouse, and Kafka for high-throughput, multi-tenant production workloads. Develop internal coding agents and define AI-native engineering practices while making decisions around storage, APIs, performance, and reliability.

Leads platform engineering efforts by designing scalable systems, developing C# and .NET Core services, improving CI/CD pipelines, automating cloud infrastructure, and advancing DevOps, GitOps, and Infrastructure as Code practices. Mentors engineers, drives technical initiatives, troubleshoots complex issues, supports on-call operations, and improves platform reliability, performance, and deployment efficiency using Kubernetes and cloud platforms.

Develop and maintain automated unit, integration, and end-to-end test frameworks for scalable virtualized server platforms. Define test strategies, performance quality gates, deployment validation, rollback verification, and test plans for microservices. Investigate deployment issues, troubleshoot root causes, collaborate with engineering teams on integration testing, improve test environments, and automate platform service deployments using scripting and CI/CD tools.

Design, develop, debug, and improve Elastic’s cloud control plane and hosted offerings. Provide technical leadership, guide cross-team architecture, establish development best practices, create technical plans, prioritize features and fixes, and collaborate globally with Support and Elasticsearch engineering teams to deliver reliable, scalable SaaS foundations.

Lead the design, development, delivery, and operation of secure, scalable authentication platform capabilities, including sign-in, account recovery, MFA, session management, authorization, and identity federation. Collaborate with Product, Security, Fraud, Compliance, and engineering teams; improve reliability, monitoring, code quality, and security practices; resolve production issues; mentor engineers; and communicate technical decisions and trade-offs.

Leads development of scalable cybersecurity products across frontend, backend, platform, and data infrastructure. Drives architecture, data pipelines, Kubernetes services, observability, API security, CI/CD, and cloud operations. Mentors engineers, leads cross-functional projects, aligns technical solutions with business goals, and evaluates responsible AI-assisted development practices. Requires extensive software engineering experience and expertise in React, TypeScript, Node.js, AWS, streaming systems, databases, distributed processing, and secure application design.

Own the technical direction and delivery of WEX’s data acquisition platform. Build reusable, high-performance batch, CDC, and streaming ingestion services with schema validation, reconciliation, recovery, lineage, security, observability, and auditability. Lead architecture and code reviews, establish testing and CI/CD practices, mentor engineers, resolve cross-team dependencies, and support production escalations. The role requires hands-on development of scalable distributed systems and configuration-driven connectors.

Build and operate production AI infrastructure powering intelligent agents at scale. Develop high-performance Rust services for model inference, orchestration, and execution; design scalable distributed systems; establish MLOps, observability, guardrails, and failure recovery; and optimize latency, throughput, reliability, and cost. Partner with agent systems and infrastructure teams to turn prototypes into hardened services serving millions of users.

Design, build, operate, and maintain Grafana’s distributed search and storage systems. Drive projects from ideation through customer delivery, own system reliability and performance, participate in on-call rotations, contribute to open-source projects, and collaborate on technical design. The role also involves mentoring teammates, learning a large cloud-based codebase, and improving services based on customer feedback.

Own the quality strategy for high-volume batch analytics systems and data pipelines. Design automated test frameworks, validate REST APIs and distributed microservices, assess architecture risks, and execute functional, performance, security, and accessibility testing. Maintain Jenkins and TestNG CI/CD suites, lead exploratory validation, influence cross-functional engineering practices, and mentor junior engineers. The role focuses on ensuring reliability, scalability, and customer trust in cloud-based, multi-tenant platforms.

Build, refactor, test, and maintain secure, scalable cloud services and microservices for Guidewire’s insurance platform. Design REST or gRPC APIs, use Java and Spring, work with containers and cloud platforms, and apply CI/CD and DevOps practices. The role also involves responsible use of AI-assisted coding tools, collaboration in agile cross-functional teams, observability, code quality, and continuous improvement.

Build and scale full-stack systems supporting tens of thousands of creators. Own features from concept through production, collaborate with Product, Design, and go-to-market teams, incorporate customer feedback, and maintain high standards for quality and reliability while shipping quickly. The role requires strong product intuition, user-centered thinking, first-principles reasoning, and end-to-end ownership in a fast-paced environment.

Lead end-to-end technical ownership for an e-commerce platform service area. Design, build, and ship production features; modernize legacy systems; establish architecture and engineering standards; optimize platform performance; plan roadmaps and sprint priorities; mentor engineers; improve developer productivity; and contribute to hiring. The role requires hands-on TypeScript, JavaScript, React, Node.js, AWS, Python, and Django experience in a remote United States or Canada environment.

Implement and ship Storage Encryption Everywhere in Firefox’s Gecko engine. Responsibilities include schema migrations, encrypted data storage, integration testing, Web Platform Tests, Gecko tests, code review, specification clarification, release shepherding, and fixing correctness, performance, and regression issues across Nightly, Beta, and Release channels.

Build and maintain scalable, cloud-native APIs and core marketplace systems. Lead software architecture and testing discussions, collaborate across teams, and improve application reliability, performance, telemetry, and operational health. The role uses .NET Core and related technology stacks, front-end JavaScript frameworks, Kubernetes, AWS, PostgreSQL, OpenTelemetry, and AI development tools.

Design, build, and maintain reliable backend APIs, services, and systems. Collaborate with stakeholders and engineering teams to deliver scalable features, shape technical roadmaps, improve tooling and processes, document services, and uphold engineering standards. The role emphasizes highly available production services, data pipelines, and fraud prevention or compliance expertise within banking or fintech.

Build and deploy software solutions at Stripe, collaborate on multi-person coding projects, learn unfamiliar systems, communicate technical work clearly, and use AI tools responsibly to accelerate development. Engineers may specialize in frontend, backend, infrastructure, or other technologies while contributing to production systems, code reviews, large codebases, and independently managed projects.

Own the end-to-end quality strategy for a connected healthcare platform, prioritizing patient safety, privacy, security, and reliability. Build and maintain web, mobile, and API test automation; define release criteria; test access controls and AI-powered features; create evaluation datasets and synthetic test data; integrate testing into CI/CD; investigate failures and defects; and mentor engineering and QA teams on quality practices and responsible AI-assisted testing.

Develop and optimize high-performance React Native weather applications used by millions. Own features end to end, including clean coding, testing, CI/CD deployment to the App Store and Google Play, performance optimization, refactoring, and collaboration across AWS, Go, Node.js, Docker, Kubernetes, and microservices environments.