Senior Backend Integration Developer

Senior Backend / Integration Developer We are looking for an experienced Backend / Integration Developer to take ownership of an existing SaaS platform and continue its development, maintenance, and expansion. The platform connects multiple third party systems through APIs and requires someone who is comfortable taking over an existing codebase, understanding the current architecture quickly, troubleshooting issues, and building new integrations. Responsibilities • Take ownership of an existing production SaaS application • Review and understand the current codebase and system architecture • Maintain and improve existing backend functionality • Build and maintain third party API integrations • Work with REST APIs, webhooks, authentication, and data synchronization • Manage complex data flows between multiple external platforms • Troubleshoot API, synchronization, database, and server issues • Improve system reliability, performance, and scalability • Maintain clean, secure, and well documented code • Manage deployments, testing, bug fixes, and production updates • Work closely with the project manager and implementation team • Provide realistic development timelines and meet agreed deadlines • Document integrations and technical processes so the platform is not dependent on one developer Technical Experience We are looking for strong experience with: • Node.js / JavaScript / TypeScript • PostgreSQL or similar relational databases • REST APIs and webhooks • OAuth and API authentication methods • Third party platform integrations • Cloud hosting and server management • Git / GitHub • API testing and debugging tools • Logging, monitoring, and error handling • Building scalable multi tenant SaaS applications Experience with POS systems, marketplace platforms, ordering systems, payment platforms, CRM systems, or other integration heavy SaaS products is a strong advantage. What We Are Looking For You should be able to enter an existing project without needing everything rebuilt from scratch. We need someone who: • Thinks independently and solves problems • Can read and understand another developer's code • Communicates clearly about blockers and technical risks • Does not disappear when something breaks in production • Gives realistic estimates instead of promising impossible deadlines • Takes ownership of tasks from development through testing and deployment • Is comfortable working on a platform that will continue adding integrations and functionality Important This is an existing commercial software platform with active development underway. More detailed information about the product, architecture, integrations, documentation, and codebase will be provided to shortlisted candidates. Please include examples of SaaS platforms or API integration projects you have personally worked on, your role in those projects, your availability.