Digital Lending Platform (NDA)
A digital lending platform for an international fintech client. As sole backend engineer and client-facing lead, I built the full loan lifecycle — from application to disbursement and repayment.
DigiCash NDA & Confidential Project
Visual assets and proprietary branding are protected per client non-disclosure agreements.
The Challenge
Digital Micro-Lending MVP for Tanzania
DigiCash Financial Services Ltd. needed a complete digital micro-lending ecosystem built from scratch per client RFP specifications. The platform required paperless mobile registration, 6-step guided loan applications, credit bureau (CRB) legal consent, automated offer calculations, multi-channel SMS notifications, and an operations admin portal — all designed for full compliance with Tanzanian financial regulations and dual-language (Swahili + English) requirements.
Key Features Delivered
End-to-end capabilities spanning mobile app applicant workflow & administrative lending operations.
DigiCash Engine
Phone registration with Onfon SMS, short-lived JWTs & HTTP-only refresh cookie rotation with theft detection.
Phone OTP & Session Engine
DigiCash Engine
Data capture (Personal, Residential, ID, Employment, Income) with draft persistence & CRB consent.
6-Step Loan Application Wizard
DigiCash Engine
Configurable loan products with customizable interest rates, origination fees, tenure options & late penalties.
Dynamic Loan Product Engine
DigiCash Engine
State machine: Draft → Review → Admin Approval → Offer Generation → Customer Acceptance → Disbursement.
Full Loan Lifecycle Manager
DigiCash Engine
Non-repudiable audit log capturing every administrative & financial action with before/after state snapshots.
Immutable Operation Audit Log
DigiCash Engine
Primary Recharts/RTK-Query Admin Console & secondary lightweight panel with Super, Ops & Support roles.
Dual Admin Portals & RBAC
Domain Modules
Decoupled NestJS 11 monolith following application → domain → dto → infrastructure layered architecture.
Prisma Models
PostgreSQL database tables spanning users, loan products, applications, disbursements, and audit trails.
REST Endpoints
NestJS APIs with strict Zod environment validation, Pino logging, and auto-generated Swagger docs.
Delivery Phases
End-to-end execution directly with C-level stakeholders from initial RFP analysis to launch sign-off.
My Role & Contribution
Client Communication & Delivery
Served as the primary technical contact directly with C-level stakeholders — converting the 50+ page RFP into technical specifications, managing requirement gathering, live demos, and milestone approvals across 9 delivery phases.
NestJS 11 Domain Monolith
Single-handedly architected and built the entire NestJS 11 backend — 17 domain modules, 30+ database models, custom loan state machines, JWT token rotation, and SMS gateway integrations.
17 feature modules with PostgreSQL schema & loan transaction safety.
JWT refresh token rotation, theft detection, Helmet & rate limiting.
Disbursement engine, repayments & non-repudiable audit logging.
Onfon SMS OTP delivery, Sentry monitoring & Pino structured logs.
NestJS Modules
Decoupled domain-driven monolith architecture.
Database Models
PostgreSQL tables & financial audit ledgers.
API Endpoints
Documented OpenAPI endpoints with Zod validation.