Java architect Jobs in Toronto, ON

Job Title: Java Architect / Principal Software Engineer
Location: Downtown Toronto, ON
Hire Type: Contract

Role Summary

We are looking for a Staff/Principal Software Engineer who thrives in ambiguity, builds systems from the ground up, and ships quickly. This is a highly hands-on Individual Contributor (IC) role with significant architectural influence.

The ideal candidate will be responsible for both system architecture and hands-on implementation, working at the intersection of edge computing, backend services, AI/ML platforms, and data science.

Key Responsibilities

• Design and build end-to-end signal flows, including edge detection, ingestion APIs, processing, storage, and downstream routing.
• Architect edge-layer solutions across edge-worker runtimes and CDN-layer compute for token detection, header manipulation, and signal capture with minimal latency impact.
• Build backend services using Java Spring Boot, including APIs, validation/normalization pipelines, data persistence, and platform foundations.
• Define integration patterns for third-party vendors, including identity and trust providers.
• Implement JWT validation, public-key caching, and deterministic signal ingestion.
• Build platform capabilities supporting ML inference, including structured data access layers, feature pipelines, and model-registry integration.
• Make technology decisions around storage, transport reliability, observability, security, and governance on AWS.
• Drive rapid prototyping, demos, iterative architecture refinement, and production implementation.
• Work closely with Data Science, Product, Engineering, and partner teams.

Must-Have Skills & Experience

• 10+ years of experience building production-grade distributed systems.
• Strong Java and Spring Boot expertise.
• Strong system design and architecture experience.
• Proven experience taking greenfield projects from 0 to 1.
• Experience selecting technologies/frameworks and building the initial architecture from scratch.
• Hands-on implementation experience - must be a strong coder, not an architecture-only candidate.
• Experience building features supporting ML inference pipelines, data normalization, feature pipelines, model serving, or similar AI/data platforms.
• Strong experience with AI-assisted development tools, such as GitHub Copilot, LLM-powered workflows, or agentic coding assistants.
• Strong AWS experience across compute, storage, networking, and IAM.
• Experience with edge computing/CDN execution environments such as Edge Workers, CDN Functions, Lambda@Edge, or equivalent.
• Experience with microservices and event-driven architectures.
• Excellent communication and stakeholder management skills.
• Ability to independently drive technical decisions in an ambiguous environment.

Critical Client Expectations

The client is specifically looking for candidates who:

• Have greenfield/0-to-1 project experience and have personally selected and established the technology framework.
• Are highly experienced with AI-assisted development while remaining strong hands-on engineers.
• Demonstrate exceptional system design and architecture capabilities.
• Have strong implementation and coding experience.
• Communicate clearly and confidently with technical and non-technical stakeholders.
• Are naturally curious and probing - candidates should ask why, what, when, where, and how rather than simply agreeing with requirements.
• Can challenge assumptions, identify gaps, and propose thoughtful technical solutions.
• Thrive in a fast-paced, startup-like environment with evolving requirements.

Nice-to-Have

• Identity, trust, or security domain experience.
• JWT/JWS, PKI, OAuth 2.0, bot detection, or token verification.
• Python experience for data engineering or scripting.
• Databricks or similar AI/data platform experience.
• Observability at scale, including distributed tracing, structured logging, and dashboards.
• Experience with multi-party integration platforms or network services.
• Open-source contributions or community involvement.