Senior Full-Stack Integration Engineer

• *Senior Full\-Stack Integration Engineer**

• *About the Role**

Build custom web applications, client portals and third\-party integrations — Stripe, Microsoft 365 and WhatsApp Business — end to end, frontend to backend, and share ownership of their architecture.

• *Key Responsibilities**

• Build and maintain integrations with Stripe, Microsoft Graph API, WhatsApp Business / Cloud API and other SaaS platforms.
• Implement OAuth 2\.0, tokens, API keys and webhooks, including error handling, retries and rate limits.
• Build web applications, dashboards and client portals using Node.js, TypeScript and React.js.
• Translate business requirements into technical solutions, investigate problems and recommend suitable approaches.
• Handle credentials and secrets securely.
• Test, debug and deploy applications across development, staging and production environments.

• *Essential**

• Ideally 3–6 years of hands\-on development experience. Practical integration experience matters more than total years.
• Strong Node.js, TypeScript / JavaScript, React.js, responsive HTML / CSS and Git skills.
• SQL experience, preferably PostgreSQL or MySQL, and a basic understanding of NoSQL.
• Experience developing REST APIs and third\-party / SaaS integrations, including OAuth 2\.0, tokens, API keys, webhooks, error handling, retries, rate limits and secure secrets management.
• Hands\-on payment gateway integration experience, such as Stripe.
• Hands\-on experience with at least one of Microsoft Graph API / Microsoft 365 or WhatsApp Business / Cloud API.
• Experience building and debugging both the frontend and backend of web applications, dashboards or client portals.
• Personally delivered at least one integration from requirements through authentication, API / webhook development, data and error handling, testing and deployment.

• *Preferred**

• Experience with both Microsoft Graph API and WhatsApp Business / Cloud API.
• Experience with Zoho Creator / Zoho APIs or other low\-code platforms.
• Familiarity with Power Automate, Zoho Flow, Make or Zapier.
• Experience with Azure or AWS, Docker and CI/CD.
• Familiarity with message queues, Redis, background jobs, monitoring and logging.
• Experience conducting feasibility analysis, building proofs of concept, creating architecture diagrams and designing systems.

• *Not Suitable For**

• Candidates whose experience is limited to low\-code platform scripting without strong API and backend fundamentals.
• Frontend\-only or backend\-only developers.
• Developers who have only used ready\-made connectors without building authentication, webhooks or error handling.