Software Engineer (4-month contract)

Role overview

AI integrations and delivery

• Design MCP servers and AI integrations using the official TypeScript MCP SDK; build tools, resources, and prompts for AI assistants and agents.
• Implement Streamable HTTP remote transport and stdio local transport where needed, following the current MCP specification.
• Connect tools to APIs and services, handling mapping, pagination, retries, idempotency, and rate limits; keep versions and schemas stable.
• Design user-focused tool sets and clear tool names, descriptions, input and output schemas, and error messages.
• Evaluate how reliably models select and call tools, improve tool design, and test with MCP clients and MCP Inspector.
• Prototype AI use cases with Product and ship promising features to production.

Security and engineering

• Implement authentication and authorization, including OAuth 2.1, so agents access only data their users are permitted to reach.
• Treat tool output as untrusted, guard against prompt injection and excessive permissions, and log tool calls without exposing sensitive customer data.
• Write clean, tested code; participate in code reviews; deploy and run AWS services through CI/CD.
• Monitor tool latency, failure rates, and usage; write setup guides and technical documentation; build for assistive technology users.

Required qualifications

• At least 3 years of professional backend development experience building and running production services and APIs.
• Strong JavaScript or TypeScript and Node.js skills; production REST API design, development, and integration experience.
• Experience with automated testing, Git, code review, and CI/CD, such as GitHub Actions.
• Hands-on experience building AI tool integrations or agent tools, integrating LLMs, using tool calling and structured outputs, prompt engineering, evaluating AI behavior, and AI-assisted development.
• Clear communication, ability to work independently and deliver quickly, and a practical customer-focused problem-solving approach.

Nice to have

• Knowledge of OAuth 2.0 or 2.1, token-based authentication, and access scopes; experience with Express.js or Serverless Framework.
• Experience with AWS Lambda, ECS, or API Gateway; Docker; MongoDB; Auth0 or similar identity providers; AI agent frameworks; or JSON-RPC.
• Experience with Infrastructure as Code, observability and monitoring platforms, third-party SaaS integrations, or web accessibility and assistive technology.

Work arrangement

• Fable is remote-first; the role follows regular Monday-to-Friday Eastern business hours.
• Occasional in-person collaboration may take place at the Toronto office; preference is given to candidates in the Greater Toronto Area, but candidates elsewhere who can travel are considered.

Pay

• Hourly pay range is $50–$70; final rate depends on relevant skills, experience, and internal equity.

Benefits and workplace

• The company describes a collaborative, mission-driven environment focused on building a more inclusive digital world.