We are scaling our debt recovery platform from a manual file-upload process into an API-first integration platform that allows banks, microfinance institutions, and digital lenders to connect their loan portfolios directly into our system. The goal is to create a secure, developer-friendly integration layer where financial institutions can push loan books and receive real-time portfolio updates through well-structured APIs and event streams. Primary connection methods will include: REST APIs (OpenAPI/Swagger documented) Secure SFTP feeds Client-side SDKs Event-driven streaming The platform will support multi-tenant financial institutions, prioritizing reliability, security, and ease of integration. Scope of Work The selected developer will design and implement the API integration architecture, including: API Platform • Define and document all public endpoints using OpenAPI / Swagger, enabling partner engineering teams to self-serve integration. • Design and deploy an API Gateway responsible for: request routing authentication and authorization rate limiting and throttling versioning monitoring Authentication should follow OAuth2 / JWT best practices. Integration Middleware • Introduce an ESB or lightweight integration layer responsible for: data transformation orchestration validation routing between services The backend services currently run on Laravel / PHP. Event Infrastructure • Implement an event-driven backbone using tools such as: Kafka RabbitMQ This layer will publish real-time portfolio events, including: new loan onboarding loan status changes repayment activity collection updates Security & Observability Implement strong operational and security practices including: • role-based access control (RBAC) • API audit logging • request tracing • production monitoring • SOC-friendly observability Developer Experience Create a reference SDK that demonstrates: authentication API connection portfolio data submission event consumption This SDK will serve as a template for partner institutions. DevOps & Delivery Deliver production-ready infrastructure including: • CI/CD pipelines • unit and integration testing • infrastructure documentation • an operational runbook so the internal team can maintain the system. Acceptance Criteria 1. Complete and validated OpenAPI specification, including request/response examples. 2. API Gateway deployed in our cloud environment, successfully passing agreed load tests. 3. Integration middleware workflows demonstrated, including at least two transformation scenarios. 4. Event architecture documented, with working publishing and consuming examples. 5. Security scan completed, with no high-severity vulnerabilities. 6. Super Admin, multi-tenant admin and AI engine mobile-first webpages. Application Requirements When replying, please share examples of previous systems where you designed or built API-driven platforms, especially in: fintech payments financial integrations regulated environments A short paragraph per project is sufficient. No full proposals are required at this stage. Final documentation and sample webpages designs will be provided separately during final alignments.