• Own the company’s billing microservice end-to-end — architecture, development, and production operations —processing 800+ invoices/month (~A$1.2M annual billing volume) for 800+ client accounts.

• Cut report generation from ~5 min to ~1 min (5?) in Celery tasks aggregating data from the Xero API and 3 internalmicroservices — query rewrites, indexing, N+1 elimination, and memory optimization under tight hardware constraints(400 MHz CPU / 128 MB RAM).

• Moved DocuSign document processing into FastAPI background tasks, eliminating client-facing lag during long-runningoperations.

• Designed and delivered 5 production microservices: B2B REST APIs and event-driven services built on Celery and Redis.

• Built a partner-facing REST API for internet service sales, integrated by 20 B2B partners; authored the external developerdocumentation.

• Integrated and maintained enterprise services across projects: Xero (financial operations), DocuSign (digital documents),Microsoft APIs.

• Worked with geospatial infrastructure data using PostGIS.

• Mentored 2 junior developers; established code review practices and internal development standards.

Stack: Python, FastAPI, Django, SQLAlchemy (async), Celery, PostgreSQL, PostGIS, Redis, Docker, AWS, Vue.js, pytest

Led a year-long migration of a fintech platform (1,000+ users) from PHP (Symfony) to Django, preserving core businesslogic throughout the transition.• Redesigned and optimized the ~50-table PostgreSQL schema for the migrated platform.
Stack: Python, Django, PostgreSQL, MySQL, Docker, Pandas, NumPy