Senior Full Stack Developer, Contract (2)
Building AI dev tools and agentic workflows with LLMs; heavy on prompt engineering, eval pipelines, and deterministic multi-step agents.
About the Role
Senior Full Stack Developer (contract) to architect and build full-stack applications and cloud infrastructure with a focus on agentic LLM workflows, prompt engineering, evaluation pipelines, and production observability. Role is open to candidates across Canada (EST hours) with local Toronto (GTHA) hires expected in-office two days per week; contract runs until December 24, 2026.
Job Description
Role
BIMM is hiring two Senior Full Stack Developers on contract (through Dec 24, 2026) to design and implement full-stack applications and cloud infrastructure that enable agentic workflows. The role combines traditional web engineering (React/Node.js, SSR, API design) with AI-focused responsibilities like prompt engineering, LLM evaluation pipelines, and building deterministic agent/tool workflows.
Key Responsibilities
Core Engineering
- Build and optimize web applications for performance and scalability (SSR, frontend and backend collaboration).
- Design and implement APIs (REST/GraphQL) and ensure production readiness, observability, and SLOs.
- Own cloud infrastructure and deployments required to host scalable, dynamic agent operations.
- Apply security best practices and integrate access/audit patterns.
AI Engineering
- Implement and maintain automated evaluation pipelines (LLM-as-judge, regression suites, golden datasets).
- Define typed input/output contracts for tools and agent skills (TypeScript interfaces, JSON Schema) and handle edge cases and structured errors.
- Own prompt engineering lifecycle: version-controlled prompt templates, parametric input injection, system/user role separation, and prompt regression testing.
- Contribute MCP tooling catalog and integrations (notably GraphQL/Apollo) and participate in rollout readiness, including SLO definition and support documentation.
- Build deterministic, multi-step agentic workflows and orchestration frameworks with graceful failure handling.
Requirements
- Must be available to collaborate in the Toronto office 2 days per week if local to GTHA; remote candidates must work EST hours.
- 5+ years working with modern frameworks and languages (REACT & NodeJS).
- Experience with SSR applications.
- Experience with GraphQL and Apollo; building or integrating REST/GraphQL APIs and defining tool interface contracts and versioning.
- Familiarity with OAuth2/OIDC, API key management, and access audit trail patterns.
- Familiarity with observability practices (logs, metrics, distributed traces) and SLO definition for production APIs.
- Hands-on experience with LLM structured output patterns (function/tool calling) and evaluation approaches (golden sets, LLM-as-judge, prompt regression testing).
- Experience building agentic workflows (multi-step tool chains, state-machine agents, or orchestration frameworks such as LangGraph, LangChain, AutoGen, or custom).
Nice to have
- Experience defining and rolling out engineering standards (coding conventions, PR workflows, testing mandates).
- Experience managing and mentoring engineers and driving AI tool adoption within teams.
- Familiarity with AWS and Docker.
- Experience with Styled Components.
- Experience with prompt caching, semantic routing, output memorization strategies, and instrumentation of LLM calls (traces, token counts) using LangSmith, OpenTelemetry, or custom solutions.
Logistics
- Contract role through December 24, 2026.
- Device requirements: Mac or Windows (no Linux), recent OS versions (Windows 11 or macOS Sonoma/Sequoia or newer; limited Windows 10 allowance), device under 4 years old, and agreement to BIMM security tooling being installed and maintained.
Culture & Perks
- Hybrid-friendly culture (Toronto HQ presence for local hires), team social events, DEI initiatives, and professional development opportunities through the Kyu Collective (training, conferences, Lunch’n’Learns).