Backend Engineer – API Integrations for AI Agents

About the role

Icalia Labs is seeking a contract Backend Engineer to design and deliver secure, usage‑aware API integrations for AI agents and developer platforms. You will work autonomously to translate third‑party documentation into production‑grade connectors, focusing on reliability, security, and precise billing.

Key responsibilities

• Define connector specifications for external APIs.
• Implement secure API proxying and authentication injection.
• Validate whitelisted API operations and request paths.
• Build vendor integrations for AI and developer platforms.
• Design cost‑metering and usage‑based billing logic.
• Develop streaming and asynchronous usage‑calculation systems.
• Create internal TypeScript SDKs and private npm packages.

Required profile

• 4+ years of backend engineering experience.
• Strong production background with Node.js and TypeScript.
• Proven ability to work independently and handle edge cases.
• Detail‑oriented mindset with a commitment to engineering quality.
• Excellent problem‑solving and communication skills.

Required skills

• TypeScript
• Node.js
• REST APIs
• HTTP, headers, authentication flows
• Web Streams / streaming token responses
• Fetch API
• npm package architecture
• Async processing
• API security best practices
• Usage‑based billing and metering logic
• SDK and middleware development