Top Software Engineer Jobs in Toronto

Develop and support a cloud-native workload credentials management solution within a SaaS platform. Responsibilities include designing scalable full-stack services, orchestration, APIs, distributed systems, and microservices; providing technical leadership; leading projects through delivery; collaborating cross-functionally; mentoring engineers; and applying engineering best practices. The role requires extensive Go development, cloud and SaaS expertise, modern JavaScript frameworks, and experience operating enterprise systems at scale.

Build and iterate full-stack systems powering AI agents, from user-facing experiences through orchestration and deployment. Research agent orchestration, prompting, and model alignment approaches; collaborate with Product, Design, and Engineering to improve usability; document findings, share technical learnings, and participate in reviews and technical discussions.

Build and iterate on full-stack systems powering autonomous AI agents, from user-facing experiences through orchestration and deployment. Research agent orchestration, prompting, and model alignment approaches; collaborate with Product, Design, and Engineering to improve usability for nontechnical users; document findings, share knowledge, and participate in reviews and technical discussions.

Own full-stack product features from technical scoping through deployment and post-launch iteration. Design schemas, APIs, and business logic; build user-facing applications across frontend, backend, and databases; collaborate with ML researchers, product, design, and engineering; incorporate user feedback; and improve development, testing, and deployment practices.

Build and scale secure automated patching infrastructure for open-source vulnerabilities. Develop Rust and Unix-based CLI tools, package-manager integrations, APIs, testing tools, and developer-facing remediation workflows. Debug ecosystem-specific issues, contribute to JavaScript, React, and TypeScript frontends, and collaborate with security researchers to deliver certified packages and high-quality patches at scale.

Build and own React Native features for Kraken’s consumer mobile app, from product discovery through launch, measurement, and iteration. Partner with Product and Design to create responsive, trustworthy financial experiences using dynamic or real-time data. Guide development for a new Asian-market app, including regional UX, connectivity restrictions, vendors, and telemetry. Contribute to architecture, performance, reliability, code reviews, and product engineering standards.

Owns quality for enterprise identity governance features from design through production. Responsibilities include creating test plans, automating API, integration, end-to-end, and UI testing, building performance and reliability tests, validating data integrity, integrating deterministic CI release gates, troubleshooting distributed systems, reviewing code, addressing production issues, and partnering with engineering, product, design, SRE, and customer teams.

Design, build, deploy, and optimize high-performance distributed data platform services supporting analytics and machine learning. Responsibilities include developing scalable streaming infrastructure, participating in design and code reviews, tuning performance, debugging production issues, collaborating cross-functionally, and mentoring engineers. The role requires expertise in distributed computing, messaging, data processing, cloud technologies, software engineering principles, and reliability practices.

Leads hands-on development of pay-related SaaS features for contingent workforce management, including jobs, worker provisioning, contracts, and integrations. Designs scalable, resilient services and contributes to architecture decisions using Python, React, and AWS. Builds and maintains RESTful APIs, relational database solutions, and high-quality tested code while mentoring engineers and communicating complex technical concepts. Works effectively with ambiguous requirements in an Agile/Scrum environment.

Build and maintain scalable, reliable backend systems and production-ready features for financial instrument data. Design low-latency, highly concurrent services and APIs used by millions of customers. Collaborate with engineering, frontend, data, business, operations, and vendors; lead complex cross-team initiatives; mentor junior developers; and improve system performance, architecture, and team workflows.

Develop and maintain scalable Java and big data applications across the software development lifecycle. Build distributed data-processing tools, REST APIs, and automation; analyze and debug systems; conduct test-driven validation; review code; and collaborate with internal teams and vendors. The role works with technologies including Apache Hudi, Trino, Spark, Kafka, cloud storage, and distributed computing platforms while promoting performance, reliability, modern engineering practices, and continuous technical improvement.

Own the architecture and technical strategy for Square’s go-to-market technology stack. Build and operate production AI agents, automated workflows, and integrations that improve sales productivity. Lead complex technical initiatives across teams, establish reliable and secure AI evaluation practices, make build-versus-buy decisions, and partner with Sales, Product, Data, and Engineering leaders. Mentor engineers, guide design and implementation, and use data and feedback to improve system adoption and business impact.

Build and operate highly reliable card-issuing software and tooling across authorization, clearing, settlement, certification, and network integrations. Serve as a technical expert on card-network specifications, protocols, mandates, and production behavior. Lead complex cross-team engineering work, debug protocol-level issues, influence network requirements, mentor engineers, improve platform reliability, and participate in on-call support for critical financial systems.

Staff Software Engineer responsible for building and operating Block’s card issuing platform at the network boundary. The role requires deep expertise in card networks, ISO 8583, authorization and clearing flows, certifications, mandates, and direct network connectivity. Responsibilities include writing production code, developing conformance tooling, debugging protocols, leading cross-team technical initiatives, influencing network requirements, mentoring engineers, supporting AI-assisted development, and participating in on-call operations for critical financial systems.

Investigate and modify browser engine subsystems through hands-on experimentation, prototyping, instrumentation, profiling, and performance analysis. Build capabilities supporting reliable programmatic web interaction while evaluating correctness, compatibility, and efficiency. The role requires deep browser internals expertise, strong C++ or Rust proficiency, systems debugging experience, and understanding of web platform behavior. Engineers will collaborate with technical leadership, use AI-assisted development tools, and document reproducible results, including unsuccessful experiments.

Own and deliver high-availability authentication, verification, and fraud experiences across web, backend, and mobile interfaces. Lead quarterly goals, technical planning, system delivery, code quality, operational availability, and on-call support. Collaborate with product, design, and analytics stakeholders, resolve complex technical and business issues, mentor engineers, and promote engineering standards. The role requires expertise in React or Vue, JavaScript or TypeScript, large codebases, scalable architecture, and effective communication.

Own the architecture and technical strategy for Square’s go-to-market technology stack. Build and operate production AI agents, automated workflows, and scalable integrations that improve sales productivity. Lead complex technical initiatives across teams, establish AI reliability and security guardrails, define evaluations and success metrics, and guide build-versus-buy decisions. Remain hands-on across prototyping, implementation, testing, deployment, and operations while mentoring engineers and influencing senior business and technical stakeholders.

Develop and ship autonomy software for outdoor, production robots across perception, localization, state estimation, motion planning, and controls. Build fleet coordination, simulation and CI, logging/telemetry pipelines, and operator tools. Validate on real hardware, support field deployments, and ensure software degrades gracefully at remote sites.

Lead development of a massively distributed edge compute platform. Design fault-tolerant systems, external APIs, high-throughput traffic routing, and Kubernetes-based resource management. Establish architecture standards, reliability metrics, security practices, and technical governance. Collaborate with AI/ML, hardware, networking, and security teams; communicate risks to executives; manage customer requirements; review code; and mentor engineers on distributed systems best practices.

Design, build, and operate large-scale distributed scanning services in Python and Go. Own systems design, implementation, deployment, scalability, reliability, observability, and production support for internet-wide and customer-specific security scans. Collaborate with security, product, data, and infrastructure teams to deliver scanning and threat-intelligence capabilities, improve architecture and performance, and mentor engineers.

Designs and develops healthcare interoperability and patient information systems using InterSystems IRIS and HealthShare. Builds HL7 and FHIR integrations, data exchange pipelines, ObjectScript applications, APIs, web interfaces, and optimized database solutions. Works directly with customers and clinical stakeholders to gather requirements, define technical specifications, conduct demonstrations and testing, and deliver compliant systems using secure protocols and controls.

Develop and optimize InterSystems IRIS and HealthShare healthcare integration solutions, PIMS platforms, patient workflows, and enterprise data exchange products. Gather customer requirements, design technical architectures, implement HL7 and FHIR integrations, build APIs and web interfaces, optimize databases and high-volume processing, and configure security and compliance controls. Support demos, testing, onboarding, and technical delivery while collaborating with customers, clinical teams, vendors, and stakeholders.

Design, build, deploy, and maintain critical software supporting scientific experiments, instruments, data systems, and infrastructure. Translate ambiguous research needs into reliable software milestones, develop integrations and high-volume data workflows, solve concurrency and performance issues, and improve testing, observability, and release practices. The role also includes architecture decisions, code review, mentoring, technical leadership, and collaboration with scientists and engineers.

Principal Software Engineer leading architecture and implementation of resilient, low-latency distributed systems for the RunMyJobs platform. Responsibilities include technical strategy, full-stack development, AI-assisted software development, CI/CD and observability, code and design reviews, quality improvement, troubleshooting, and mentoring. The role requires expertise in Java, microservices, cloud platforms, containers, frontend technologies, databases, automated testing, and AI developer tools, with broad technical ownership but no direct people management.

Build, maintain, and improve highly automated build, release, testing, and continuous delivery infrastructure. Develop internal tools and automation, collaborate with Development, QA, and Operations, and implement AWS-based technologies to scale infrastructure and accelerate testing. Partner with internal customers to roll out projects, monitor adoption, gather feedback, and refine processes. The role requires software development experience, cloud and containerization knowledge, and cross-functional collaboration.