Hiring: Senior Backend API Integration Developer

Job Type: Project-Based / Contract

Work Mode: Remote

Experience: 3+ Years (Relevant Experience Required)

Job Overview

We are looking for an experienced Backend API Integration Developer to build a fully automated Google Workspace mailbox integration system within an existing SaaS platform.

The primary objective is to automate Google Workspace mailbox authorization and connection to third-party platforms using official APIs, without browser automation or manual mailbox-by-mailbox login.

The ideal candidate must have strong experience with Google Cloud, OAuth 2.0, Google Workspace APIs, and multi-tenant SaaS architecture.

Key Responsibilities

- Develop secure, API-based Google Workspace mailbox integration workflows.
- Implement Google OAuth 2.0, service accounts, and Domain-Wide Delegation.
- Configure centralized Google Cloud API access across multiple Google Workspace tenants.
- Integrate Google Workspace mailboxes with third-party platforms using their official APIs.
- Implement administrator-authorized authentication workflows where supported.
- Build scalable backend automation for connecting multiple mailboxes across independent tenants.
- Handle OAuth tokens, API permissions, authentication errors, and connection verification.
- Implement background jobs, API rate limiting, retries, and error handling.
- Integrate the functionality into an existing SaaS application.
- Ensure security, reliability, and proper handling of sensitive credentials.

Required Technical Skills

- Solid experience with Google Workspace APIs and Gmail API.
- Advanced knowledge of OAuth 2.0 and Google Cloud IAM.
- Practical experience with Google Workspace Domain-Wide Delegation.




- Experience with Google service accounts and Admin SDK.
- Strong REST API integration and backend development skills.
- Experience with third-party API authentication and integrations.
- Understanding of multi-tenant SaaS architecture.
- Experience with secure token management and API authorization.
- Proficiency in Node.js, TypeScript, Python, or another relevant backend language.

Important Requirements

- Must be able to work with official APIs without relying on browser automation.
- Must understand the difference between Google API authorization and third-party OAuth authentication.
- Must be able to investigate API documentation and identify technical limitations.
- Must have experience developing reliable, production-ready integrations.
- Must be comfortable working within an existing codebase.

Browser automation experience alone is not sufficient for this position.

Project Deliverables

- Google Cloud and Google Workspace API integration.
- Secure multi-tenant authorization architecture.
- Third-party platform integration through supported APIs.
- Automated mailbox connection workflows.
- Bulk connection processing and status verification.
- Error handling, logging, and retry mechanisms.
- Tested, documented, production-ready backend implementation.

How to Apply

Please share

- Your relevant experience with Google Workspace APIs and OAuth 2.0.
- Examples of similar API integration projects.
- Your experience with Domain-Wide Delegation and service accounts.
- Your preferred backend technology.
- Your estimated availability and project rate.

Note: We are specifically looking for someone with hands-on Google Workspace API and OAuth integration experience, not a general website developer.

📌 Senior Backend API Integration Engineer (India)
🏢 MithMill
📍 India