Senior Full Stack Developer, Contract

BIMM • Toronto, ON

2d • CA$50 - CA$100 • Hybrid

About The Position

BIMM is seeking a Senior Full Stack Developer on a contract basis until December 24, 2026. This role is hybrid for local candidates in the GTHA region, requiring two days per week at BIMM HQ in the Distillery District. Remote candidates across Canada are welcome, with the expectation of working EST hours. BIMM is a Toronto-based agency that combines data, technology, and creativity to deliver high-performing campaigns and digital products. The Technology department is a distributed team of over 50 Developers, QA, and Architects working with a leading-edge technology stack. This is an existing vacancy with a dedicated workspace available.

Requirements

• Be available to collaborate with the team in our Toronto office 2 days per week.
• 5+ years of working knowledge with modern frameworks and languages (REACT & NodeJS)
• Familiarity with OAuth2/OIDC, API key management, and access audit trail patterns
• Experience with SSR applications
• Experience with GraphQL and Apollo
• Experience building or integrating MCP-compatible REST/GraphQL APIs; familiarity with tool interface contracts, versioning, and consumer documentation.
• Familiarity with SLO definition and basic observability practices (logs, metrics, distributed traces) for production API services.
• Hands-on experience with LLM structured output patterns: function/tool calling
• Familiarity with LLM evaluation approaches: building golden test sets, LLM-as-judge pipelines, and prompt regression testing; ability to quantify output quality with measurable metrics rather than vibes.
• Experience building agentic workflows — multi-step tool chains, state machine-based agents, or orchestration frameworks (LangGraph, LangChain, AutoGen, or custom) — with an emphasis on deterministic routing and graceful failure handling
• Use a Mac or Windows device (Linux or other OS not supported)
• Windows 11 or macOS Sonoma/Sequoia or newer is required
• Windows 10 may be used up to October 2025
• macOS Big Sur, Monterey, and Ventura are not permitted
• Device must be less than 4 years old
• Agree to have us install and maintain BIMM’s security tools on your device. These tools must remain active, with all permissions and configurations unchanged for the duration of the contract

Nice To Haves

• Demonstrated experience defining and rolling out engineering standards at a team or org level (coding conventions, PR workflows, testing mandates, API contracts)
• Experience managing and growing engineers — performance conversations, career development, structured feedback
• Track record of driving AI tool adoption within an engineering team — not just using the tools but creating the onboarding, guidance, and culture around them
• Comfort operating at the intersection of technical leadership and delivery management — you can write the ADR and run the retro
• Familiarity with AWS & Docker
• Experience with Styled Components
• Experience with prompt caching, semantic routing, or output memorization strategies to reduce non-determinism at scale.
• Ability to instrument LLM calls with structured traces (input, output, latency, token count, tool calls invoked) using frameworks like LangSmith, OpenTelemetry, or custom logging; can define SLOs for agent task success rates

Responsibilities

• Optimizing website performance: Making sure websites load quickly and efficiently.
• Developing APIs (Application Programming Interfaces): Creating interfaces that allows different applications to communicate with each other.
• Understanding the entire web development process: Having a holistic view of how the front end and back end work together.
• Working with different technologies: Being proficient in a variety of programming languages, frameworks, and tools.
• Build and maintain automated evaluation pipelines (evals) for agent and skill outputs — including LLM-as-judge scoring, regression test suites, and golden dataset validation — so that prompt and model changes are measurable before they ship.
• Define strict input/output contracts for MCP tools and agent skills using typed schemas (TypeScript interfaces, JSON Schema); ensure tools handle edge cases, surface structured errors, and never return ambiguous output that an LLM must interpret.
• Own the prompt engineering lifecycle for assigned tools and skills — version-controlled prompt templates, parametric input injection, and structured system/user role separation — ensuring prompts are testable, reproducible, and free of implicit context drift.
• Contribute to the team's MCP tooling catalog — implement, test, and document MCP-compatible API integrations (particularly GraphQL/Apollo and developer portal tooling); participate in rollout readiness reviews including SLO definition and support contact documentation.

Benefits

• Access to Kyu Collective network’s resources, training, offices, and more.
• On-site Lunch n’ Learns, conferences and online courses for personal and professional development.
• Inclusive and accessible work environment.
• Accommodation for recruitment/interview process available upon request.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed