Top Software Engineer Jobs in Toronto

Design, build, and operate production AI agent systems using modern LLM APIs and agent SDKs. Own end-to-end architectures, integrations, observability, progressive delivery, and reliability. Mentor engineers, participate in technical design reviews, and collaborate with product peers to deliver scalable, stable legal AI agent tooling.

Lead technical strategy and architecture for fintech products, mentor engineers, design and implement high-throughput distributed web applications (invoicing, payments, payroll), drive multi-team technical decisions, review code, and improve engineering practices.

Hands-on technical leader building full‑stack customer-facing features across React/TypeScript frontends and Python/Node backends, contributing to AI capabilities (LLM integrations, agentic workflows, MCP), setting technical standards, mentoring engineers, and driving delivery from design through production.

Build full‑stack web features from zero to one, integrate with third‑party APIs, design and manage state machines for financial workflows, own features through launch and post‑launch customer iteration, and maintain high code quality and accountability.

Design, build, and maintain backend foundations and internal developer platform tooling. Integrate AI-native workflows, consolidate platform primitives (developer portal, local dev, service templates, GraphQL, event-driven patterns, OpenAPI), and improve CI/CD pipelines. Collaborate with platform and product teams and raise engineering standards to accelerate developer productivity.

Design, build, and maintain backend foundations and tooling for an internal developer platform. Lead consolidation of platform primitives (developer portal, templates, GraphQL, event-driven patterns, OpenAPI, CI/CD). Collaborate with product teams, raise engineering standards, and integrate AI-native workflows to accelerate developer productivity.

Lead design and implementation of compliance and multi-region deployments, build IaC (Terraform/Atmos) for AWS/GovCloud, develop full-stack features (TypeScript/React Native), establish shift-left tooling, ensure architectural consistency across regulated and commercial environments, drive cross-team technical initiatives, troubleshoot distributed systems, and produce documentation and audit-ready standards.

Build and maintain a shared quality platform and test automation frameworks, design AI‑assisted test authoring and test harnesses, own CI integration and build reliability, eliminate flaky tests and systemic test debt, deliver shared testing utilities, collaborate with product teams, Quality Advocates, and SRE, and evaluate/adopt emerging AI testing tools to improve developer productivity and release confidence.

Design and implement full-stack customer-facing features using React, TypeScript, and Python. Contribute to AI-powered capabilities (LLM integrations, agentic workflows, MCP/A2A), ensure code quality, collaborate with product and design, own workstreams end-to-end, and mentor through pairing and reviews.

Own and evolve high-throughput backend services that deliver machine learning-powered predictions to merchants. Responsibilities include API design, service decomposition, Python development, PostgreSQL and Kafka integration, distributed systems reliability, observability, feature pipelines, ML serving, model deployment, versioning, rollback, and prediction monitoring. The engineer will partner with Data Science, lead architectural decisions and technical reviews, mentor teammates, and establish strong engineering practices for production data products.

Design, implement, and maintain scalable Python/Django infrastructure and distributed systems on AWS. Own features from conception to deployment, troubleshoot complex issues, optimize database performance, and collaborate with product and engineering teams to deliver production-ready, well-tested solutions for large datasets.

Own the full software development lifecycle for a healthcare admissions platform. Build and release React interfaces, REST APIs, background services, internal dashboards, feature-flag systems, and DevOps automations. Write TypeScript and SQL, maintain scalable distributed systems, improve workflows, triage production incidents, and deliver automated testing and zero-downtime releases. Translate customer needs into reliable product capabilities that improve post-acute care admissions and placement decisions.

Design and develop scalable, high-performance data and API infrastructure for real-time processing. Mentor engineers and collaborate with teams to enhance AI model evaluations.

The Full-Stack Product Engineer will design and develop AI-focused products, manage the feature lifecycle, and advocate for process improvements.

The role involves designing and building data pipelines for analyzing user feedback on AI models, ensuring data quality and infrastructure scalability.

Lead transaction reconciliation efforts, develop scalable ledger infrastructure, implement payment flows, and own backend platform projects end-to-end.

As a Senior Backend Engineer, you'll design scalable backend systems, build foundational architecture, and manage complex projects within a voice AI-driven platform.

As a Senior Full-Stack Engineer at Retell AI, you'll develop scalable systems and intuitive interfaces, bridging backend integrations with frontend experiences, focusing on voice automation solutions.

Develop, integrate, and unit test features for Nokia's Service Router OS. Collaborate with product managers and QA to gather requirements, troubleshoot and perform root cause analysis, and take ownership of modules while working cross-functionally to deliver high-quality embedded software.

Lead and deliver full-stack SaaS features: design architecture, implement Node.js back-end APIs, develop React/Vue/Ember front-ends, write tests, debug, mentor engineers, and collaborate in Agile to build scalable cyber-risk solutions.

Own and deliver end-to-end backend and platform systems that move real money. Collaborate with Product and Design to define scope, build reliable production services, participate in on-call and incident response, and improve team tooling and processes.

As a Staff Software Engineer at Arc, you will lead the design and development of a new AI-native banking platform, focusing on reliability and scalable systems for cash management and treasury solutions, while influencing product direction and mentoring team members.

Build high-performance, scalable simulation infrastructure and tooling for autonomous vehicle development. Design systems for scenario generation, simulation execution, synthetic data, and reinforcement-learning workflows. Collaborate with ML, perception, and controls teams to improve realism, performance, and validation pipelines while writing production-quality C++ and Python code, contributing to architecture, testing, and documentation.

Design, build, and optimize high-performance AI infrastructure systems to support intelligent agents, ensuring reliability and scalability for millions of users.

The Staff Software Engineer will design and implement core platform development, improve system foundations, and lead technical initiatives to enhance AI automation deployment across organizations.