Top Python Jobs in Toronto

Design, build, and maintain SparkSQL/PySpark data pipelines in the central data lake to ingest IoT, product, and unstructured data (video/audio). Produce reliable computed tables for analytics, model training, and dashboards; integrate external datasets; ensure high data quality and uptime; and collaborate with Data Science, ML, and cross-functional teams.

Lead detection, incident response, and digital forensics across macOS/Windows/Linux; act as Incident Commander, triage alerts, use SIEM, build investigation scripts and automated runbooks, collaborate with stakeholders on insider threat and security operations improvements.

Design, build, and operate scalable data ingestion, replication, and lakehouse infrastructure to move petabytes of data into a Delta Lake on S3. Improve reliability, observability, security, and developer experience for Spark/Databricks processing. Develop internal libraries and tooling (Go/Python), collaborate with cross-functional teams, and help shape long-term data platform and AI-ready infrastructure.

Design, build, and operate large-scale Spark/PySpark data pipelines and the enterprise data platform. Implement data integrations, transformations (Python/SQL), monitoring, and data quality. Build MCP servers and AI-enabled tooling, optimize performance, mentor engineers, and lead cross-functional data projects to enable analytics and automation.

The Senior Data Platform Engineer at 1Password will design, build, and maintain data systems and streaming architectures, ensuring data quality and governance for real-time access.

Senior individual contributor building and maintaining underwriting and credit decisioning ML systems for Cash App Borrow and Afterpay. Responsibilities include feature engineering, model training, calibration, experimentation, deployment, monitoring, and portfolio-level analysis. Collaborate with cross-functional teams to align models with business and regulatory goals and develop AI-native engineering workflows and governance for reliable, auditable model development.

Design, build, and operate distributed ledger, transaction, settlement, and treasury systems. Develop durable ledgering APIs, emit trusted data for finance, maintain high-reliability services to SLOs, lead complex cross-team projects, mentor engineers, and integrate AI tooling across the development lifecycle.

Lead technical direction for developer platform tooling: CI/CD, build systems, and AI coding agents. Design, build, and scale AI agents for coding, code review, testing, release automation, and incident response. Standardize tools, mentor engineers, drive cross-team technical projects, and represent the platform externally.

Design and build a next-generation reliability platform for production systems, lead delivery of quarterly goals, collaborate across product/design/analytics, support operations and on-call, set code and design standards, mentor engineers, and integrate AI/LLM-assisted tooling to improve service health and debugging.

Lead and deliver backend batch infrastructure work: own quarterly goals, design and build reliable scalable compute for batch workloads, collaborate with product and stakeholders, run ops/on-call, set code/design standards, mentor engineers, and drive platform reliability and performance.

Lead the evolution of the recommendations engine system into a scalable distributed architecture, ensuring production stability and performance while mentoring engineers and collaborating with ML teams.

The Senior Software Engineer will design and develop scalable systems for a cloud-based SaaS platform, lead technical discussions, and ensure high-quality code delivery.

Own, build, and optimize Spark-based production data pipelines and ML data lake on GCP Dataproc to support recommender systems. Collaborate with ML engineers, resolve performance bottlenecks, and deliver scalable, reliable data products for AI-driven personalization.

The Senior Data Engineer will design and maintain streaming data pipelines, develop analytical databases, and ensure data system reliability while collaborating with teams across the organization.

Build and maintain scalable, reliable ML data platform systems to support dataset generation, model training, analytics, monitoring, and large-scale inference. Collaborate with ML, software, and infrastructure engineers to design cost-efficient data lake and training infrastructure using vendor and open-source tools to enable next-generation ML models.

Build, operate, and extend Affirm's data platform and application tooling to enable self-service data applications at scale. Implement platform features (provisioning, CI/CD, access control), integrations, data governance, automation, observability, and on-call operations. Contribute to roadmap for semantic layers, agentic data tooling, and AI-native workflows while raising engineering and operational standards.

Build and maintain scalable integration and end-to-end test automation frameworks and CI pipelines. Optimize test execution, improve stability and reporting, support engineering teams with triage and best practices, write technical specs/ADRs, participate in on-call rotation, and collaborate across regions to evolve the companys test strategy and developer productivity tooling.

Design, deploy, and maintain end-to-end ML-driven risk solutions at scale to detect and prevent fraud, abuse, and credit risk. Lead technical decisions, build ML tooling and processes, apply state-of-the-art models and third-party data, investigate emerging risk patterns, and collaborate with platform and cross-functional teams to ensure reliable real-time model operation.

Senior Sales Engineer supporting pre-sales for Mastercard Identity in North America. Act as product expert to qualify prospects, design technical solutions, run proofs of value, provide training, create documentation, present at events, and relay customer feedback to Product. Leverage data science and machine learning knowledge, API/web architecture expertise, Python and SQL skills, and strong communication to drive sales and ensure smooth onboarding.

Analyze advertising inventory to maximize value, design tests, synthesize data into reports, and identify revenue opportunities in gaming.

Build and maintain agentic workflow components and the platform requirements knowledge base to ensure features ship across GitLabs deployment targets. Implement integration surfaces (issues, MRs, design docs, CI/CD), collaborate with platform teams to translate expertise into structured requirements, and write tests, documentation, and evaluations for agentic-workflow behavior and assessment accuracy.

Develop and maintain cloud-based IoT applications for manufacturing. Design secure, scalable full-stack solutions, APIs, data integrations and pipelines. Collaborate with architects, product owners, developers, and stakeholders; follow DevOps and agile practices; mentor team members and troubleshoot production issues.

Test and validate AI models and software for automotive use cases: generate ground truth, build annotated datasets and testing frameworks, evaluate technologies, support R&D engineers, coordinate projects and outsourced work, and collaborate with internal and external partners to drive innovation and product readiness.

The Senior Developer Experience Engineer will own CI/CD infrastructure and internal tools, improve developer productivity, and foster team collaboration through effective tooling and automation.

Build and maintain backend features for Agent Observability across the GitLab monolith and AI gateway. Design and implement GraphQL/REST APIs, improve automated tests (RSpec), collaborate cross-functionally, troubleshoot production issues on Tier 2 on-call, and help shape responsible AI integration and platform architecture.