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.

Work arrangement
No