Marketplace Backend Modernization (Hexagonal Arch + Airflow)

Brickbro is an established real estate marketplace whose NestJS backend had accumulated significant technical debt over time. Tight coupling between modules, outdated patterns, inconsistent data flows, and architectural inconsistencies slowed feature delivery and increased maintenance overhead.

Rather than rebuilding the platform from scratch, the system was incrementally modernized. The backend was upgraded to the latest NestJS version and the existing Hexagonal Architecture (Ports & Adapters) implementation was refined and standardized. Architectural boundaries were clarified, adapters were better isolated, and dependency inversion was enforced more consistently — improving testability, maintainability, and long-term scalability while preserving production stability.

On the data layer, the platform already leveraged Apache Airflow for DAG-based ETL orchestration. I ramped up quickly on the existing workflow system and contributed enhancements to Python-based extraction, transformation, validation, and loading processes across MongoDB (document storage) and PostgreSQL via Prisma (relational queries). This strengthened data consistency, improved task observability, and reduced operational friction.

The Next.js frontend was further enhanced using Atomic Design principles to improve modularity and scalability. Google Maps API (Autocomplete) was integrated for property search, and external third-party APIs were consumed through well-defined backend adapter layers. Select serverless components were introduced where stateless compute improved performance and deployment flexibility.