OrderX — Event-Driven Order Service
Event-driven order processing with APISIX ingress, Kafka-backed async workflows, and real-time SSE/WebSocket notifications.
- Go
- Gin
- Apache APISIX
- Apache Kafka
- PostgreSQL
- +6
Available for software & platform work
Software Engineer specialising in Golang, distributed systems, and event-driven architecture.
I have extensive experience building reliable software for payments, identity management, and Web3 platforms. Based in Ho Chi Minh City.
~/portfolio — zsh
whoami
matthew-nguyen · software engineer
cat focus.txt
golang · kafka · keycloak · postgresql · redis · grpc · quic · connectrpc
stack --recent
multi-tenant payment platform · web3 wallet · blockchain sdk · reusable platform libraries
Things I've built.
View all (3) →Multi Aura — Social Networking Platform
Real-time social platform with chat, content interaction, AI-powered Vietnamese moderation, and graph-based relationship modeling.
- Go
- Fiber
- Python
- PhoBERT
- gRPC
- +5
Hihand Shortener — URL Shortening Service
High-performance URL shortener with Base62 encoding and Redis-backed O(1) redirection.
- Go
- Gin
- Redis
- Docker
- Render
- +1
Where I've been building
Full timeline →Golang Developer
Nexsoft Technology06/2026 — PresentHo Chi Minh City, Vietnam · On-site
- Designed and shipped reusable platform components shared across multiple backend services — standardised logging, transport, middleware, and common infrastructure.
- Designed a reusable multi-chain blockchain SDK that abstracts chain-specific implementations behind a unified API: wallet management, address derivation, transaction signing, and Flutter FFI integration for backend services and native mobile apps.
- Built a high-performance networking library on QUIC / HTTP-3 with bidirectional streaming, large file transfer, progress reporting, and context-aware cancellation.
- Delivered internal gRPC / ConnectRPC services over Protocol Buffers for efficient inter-service communication.
- Implemented a centralised RBAC authorisation layer with Casbin, giving consistent permission enforcement across backend services.
- Built platform libraries adopted across multiple services, reducing duplicated implementation and improving development consistency.
GogRPCConnectRPCProtocol BuffersQUICHTTP/3Flutter FFIPostgreSQLRedisCasbinBlockchain (EVM, SVM)
Backend Developer
ESOL Technology Solution JSC01/2025 — 05/2026Ho Chi Minh City, Vietnam · On-site
- Built and deployed backend services for merchant management, payment processing, and partner integrations in production as part of a multi-tenant SaaS payment platform.
- Implemented payment integration flows for Virtual Account and QR instruments, and integrated with banking systems (e.g., BIDV) for real-time transaction processing via IPN callbacks.
- Designed Kafka-based event-driven workflows for IPN handling, transaction processing, and dynamic fee calculation — asynchronous and scalable.
- Developed Open API integration flows for merchants, covering authentication, authorisation, and payment processing for third-party systems.
- Implemented outbound IPN callback mechanisms to push transaction events to internal services and merchant-configured endpoints.
- Built a risk-mitigation module that detects and alerts on suspicious transactions based on configurable policies.
- Extended Keycloak 26 (IAM) using custom Java SPIs for platform-specific authentication and authorisation flows.
- Integrated with SFTP servers to retrieve reconciliation files and used AWS S3 for scalable file storage within processing workflows.
- Built payment and e-menu frontends with ReactJS, TypeScript, Tailwind, and Antd, integrating frontend workflows with backend APIs.
- Improved observability with Prometheus metrics and structured logging across services.
GoKafkaKeycloakJava 21PythonPostgreSQLAWS S3SFTPPrometheusMQTT (EMQX)Odoo 18ReactJSTailwindAnt Design
From the writing desk.
View all (3) →4 min read
Why I Prefer Event-Driven Architecture (and When I Don't)
Event-driven design decouples submission from processing, but it is not a default. A look at when EDA wins, when it loses, and what to design around.
- Backend
- Distributed Systems
- Event-Driven Architecture
- Kafka
4 min read
Rate Limiting at Scale: Picking the Right Bucket
A walk through token bucket, sliding window, and leaky bucket — and why the choice of algorithm is the smallest part of a distributed rate-limiting design.
- Distributed Systems
- Rate Limiting
- Redis
- Backend
5 min read
Designing Kafka Consumers in Go: Idempotency, Offsets, and the Poison Pill
Idempotency keys, offset commits, and poison-pill handling: the parts of a Kafka consumer design that nobody notices until they are wrong.
- Go
- Kafka
- Distributed Systems
- Backend
Need a software engineer who can own the platform layer?
Reusable platform libraries, identity & access management, payment systems, and blockchain infrastructure — shipped to production across multi-tenant and event-driven environments.