Backend Engineering Intern
Affinity Africa
00. Impact
1
End-to-end loan automation engine
2
Month internship — handoff-ready system
100%
Multi-stage lending operations structured
01. Overview
Co-developed the end-to-end backend engine for a loan automation platform using FastAPI and MongoDB, converting multi-stage lending operations into structured, auditable workflows.
02. The Company
Affinity Africa
Affinity Africa is a digital banking platform headquartered in Accra, Ghana, on a mission to bring affordable, accessible financial services to underserved communities across the continent.
affinityafrica.com03. Engineering Case Study
The Context
Affinity Africa needed to digitize their personal and business loan lifecycle. The manual lending process involved multiple complex stages (Application, Analysis, Appraisal, Approval, Contracting, Disbursement) across diverse roles (Customers, Relationship Officers, Analysts, Approvers, Admins), requiring strict workflow integrity, auditability, and data protection.
The Architecture
I co-developed the end-to-end Loan Automation Platform backend using Python, FastAPI, and MongoDB. We built REST APIs handling JWT authentication, Role-Based Access Control (RBAC), loan intake, credit-referencing integration, state-transition rules, and secure document management, all deployed via Docker.
Technical Challenges
Translating complex financial compliance rules into software state machines was difficult. We had to balance rapid implementation with financial-grade maintainability, explicitly enforcing authorization boundaries in the backend (not just the UI) and handling concurrent stage transitions securely.
Measurable Impact
Within a two-month internship, we delivered a handoff-ready, prototype backend that successfully modeled the entire six-stage loan lifecycle. We achieved 100% workflow structuring, passing 177 automated Pytest backend tests and providing comprehensive OpenAPI documentation for future engineers.
04. Key Responsibilities
Co-developed the end-to-end backend engine for the loan automation platform
Designed APIs and data models for loans, documents, batches, assessments, history, decisions, SLAs, audit logs, notifications, and configuration
Converted multi-stage lending operations into structured, auditable workflows
Collaborated with product and frontend contributors on integration and workflow behavior
05. Key Achievements
Designed APIs and data models spanning loans, documents, batches, assessments and history, decisions, stage SLAs, audit logs, notifications, and configuration.
Delivered a handoff-ready system within the two-month internship while collaborating closely with product and frontend contributors on integration and workflow behavior.