Brian W Tjahjadi

Software Engineer

About Me
Blog
Experience

Experience

PT Maestro Proxima Indonesia

Software Engineer Intern

Mar 2026 - Sept 2026 ☆ Jakarta, Indonesia

  • Built an AI-powered PropTech platform across React/TanStack Start, NestJS, PostgreSQL/Drizzle, Redis, LangGraph, and TypeScript, spanning frontend, backend, AI, and cloud deployment with Railway.
  • Developed a Gemini/LangGraph AI assistant for web and WhatsApp; benchmarked agent architectures (intent routing, ReAct) / models (Gemini, Kimi, Mistral, etc.), built vectorless RAG that reduced knowledge-base conversation costs by ≈70%, and developed proprietary self-hosted LangGraph/Fastify AI runtime with observability.
  • Designed Xendit payment and subscription infrastructure with cards, QRIS, trials, recurring billing, webhooks, and concurrency-safe background processing.
  • Drove WhatsApp migration from a third-party BSP to Meta Cloud API, adding native messaging features while saving ≈Rp1.000.000/month in fixed costs.
  • Built the frontend with React and drove the migration from React Router v6 to TanStack Start, redesigning rendering and data fetching around prerendering, client-side rendering, prefetching, query / route caching, and Suspense to reduce runtime infrastructure cost while maintaining page-load performance.

oNex

Software Engineer Intern

Apr 2025 - Dec 2025 ☆ Sydney, AU

  • Architected and implemented data pipeline for ingesting and preprocessing mobile time-series data on AWS and railway, supporting continuous online learning of downstream ML models.
  • Built personalized content-based recommendation service with Python, embedding models, and vector databases for fast ANN vector search and tailored user recommendations, integrating with our backend using gRPC.
  • Rewritten non-composited CSS animation background on landing page using WebGL2, delivering GPU-accelerated graphics and eliminating lag on low-spec devices.
  • Collected user feedback and proposed landing page improvements to boost engagement; implemented features using Astro, TypeScript, TailwindCSS, and SolidJS via an island architecture.

Sydney Interplanetary Rover Initiative (SIRI)

Software Engineer

Apr 2024 - Dec 2025 ☆ Sydney, AU

  • Passed the Australian Rover Challenge (ARCh)'s critical design review stage at the first year of attending the competition, accepted into the upcoming system acceptance review.
  • Led development of base station control panel for remote command and telemetry of our flagship rover using Foxglove, React, and ROS2.
  • Implemented rover's autonomous AI in the form of a behavior tree using BehaviorTree.CPP and BehaviorTree.ROS in C++.
  • Developed ROS2 C++ controllers for autonomous and manual rover steering (spin and 4-wheel convergent ackermann) alongside ESTOP and keep alive mechanisms for rover safety using Python and C++ ROS2 nodes.
  • Upgraded simulation and deployment workflows to follow ROS2 best practices (upgrading to Python, xacro urdfs, docker).

USYD Cybersecurity Society

Software Engineer

Aug 2024 - Jan 2025 ☆ Sydney, AU

  • Built Django REST API endpoints to serve team and member data from PostgreSQL.
  • Added tooling to auto-generate database schema diagrams, improving internal documentation.

Sydney Institute for Astronomy (SIfA)

Undergraduate Research Assistant

Mar 2024 - Jun 2024 ☆ Sydney, AU

Sydney Institute for Astronomy (SIfA)

Undergraduate Research Assistant

Sept 2023 - Jan 2024 ☆ Sydney, AU

Coles Group

Service and Trolleys Team Member

Mar 2023 - Sept 2023 ☆ Sydney, AU