Senior Software Engineer

kien@maneki.tech GitHub LinkedIn

Senior Software Engineer with 14+ years of hands-on experience across the full stack. Polyglot engineer (Go, TypeScript, Java, Python) specializing in distributed systems, micro-frontend architecture, and fine-grained authorization.

Skills

System Design

Microservices Event-Driven Architecture DDD Fine-Grained Authorization (OpenFGA) API Design (REST, GraphQL)

Frontend Architecture

React Web Components (Lit) Micro-Frontends (Module Federation) Atomic State Management Component-Driven Development Multi-Brand White-Labeling

Distributed Systems

Kafka Redis Elasticsearch PostgreSQL SQL & NoSQL

Languages

Go TypeScript Java Python

Experience

Xendit Pte Ltd — Senior Software Engineer

March 2021 – Present

Southeast Asian fintech providing payment infrastructure across Indonesia, the Philippines, Hong Kong, Mexico, and beyond.

Auth Platform | Engineer | Team of 2

Designed and built a mission-critical fine-grained authorization service using OpenFGA — a single point of dependency for all product APIs and the merchant dashboard. Handles dynamic permission overrides across 5 product types and 140+ currency pairs with P99 latency under 40ms.

  • Architected an FGA system using OpenFGA to replace legacy Postgres-based permission checks, supporting real-time blocklist/whitelist overrides across 5 financial products and 140+ currency pairs
  • Designed a modular FGA model with source/destination/pair-level granularity, enabling country-office-level currency restrictions without downtime
  • Built the access control admin UI that Ops teams use during merchant onboarding. The interface gives operators granular control over which products and currency pairs each merchant can access, making permission changes safer, more explicit, and easier to manage without engineering support.
Go 1.24 Echo v4 OpenFGA PostgreSQL Redis Kafka

Regional Dashboard | Frontend Lead | Team of 6

Led frontend development for Xendit’s global expansion, shipping 5 cross-border products in under 6 months — Xendit’s highest-margin product line.

  • Delivered cross-border payments, balance conversion, cross-border payouts, withdrawals, and FX management — 5 products in <6 months
  • Modernized the frontend tech stack through the strangler pattern — no major rewrites, zero downtime
  • Built a scalable authorization layer ensuring compliance with local and global regulatory requirements across new markets
  • Optimized frontend performance, reducing initial load time by ~30%
React 18 TypeScript Module Federation React Compiler Jotai Radix UI

Transaction Monitoring System | Senior Software Engineer | Team of 6

Built a compliance-driven transaction monitoring platform from the ground up.

  • Developed a rule management UI for risk and compliance teams
  • Built the core rule engine to evaluate transactions in real-time and generate alerts
  • Integrated a third-party case management system for investigation workflows
  • Designed ETL pipelines to consolidate transaction data from multiple upstream sources
React 18 TypeScript Go Kafka

Merchant Dashboard | Senior Software Engineer | Team of 5

Maintained and evolved a Module Federation monorepo hosting 14 micro-frontends, 3 BFF gateways, and 3 shared libraries serving multi-brand fintech dashboards.

  • Developed a TUI launcher for local development handling submodule management across 21 git submodules
  • Supported multi-brand white-labeling across 4 fintech brands with shared infrastructure
  • Leading migration of the authentication layer to SuperTokens
React 18 Module Federation Redux Jotai Node.js/Express Nx Vite

Hearti Lab Pte Ltd — Product Developer Lead

October 2019 – February 2021

CYBERhythm | Lead | Team of 6

Led development of a multi-cloud cybersecurity platform for SMEs, providing unified security monitoring across AWS, Azure, GCP, and Alibaba Cloud.

  • Led a cross-functional team from architecture through delivery
  • Designed and built the CI/CD pipeline on Azure DevOps with Docker/AKS
  • Integrated 4 cloud providers, open threat intelligence feeds, and a payment gateway
  • Built ETL pipelines with Airflow to consolidate security events into a unified dashboard
Django React/Redux Spring Cloud Airflow PostgreSQL Elasticsearch Docker/AKS

Helius Technologies — Senior Application Developer

May 2018 – October 2019

DBS Digimarkets

Built an FX trading platform for DBS enabling traders to request quotes and book deals, with data-driven analytics.

  • Designed and developed the platform end-to-end, from Polymer/LitElement frontend to Spring Cloud backend with GraphQL APIs
  • Built a business rule engine service using OpenL Tablets
Polymer/LitElement Spring Cloud GraphQL Kafka Elasticsearch Docker/OpenShift

FPT Software Limited — Software Engineer

June 2014 – May 2018

Built retail and configuration systems for Starhub (AngularJS, Spring Boot, Neo4j) and a high-availability program guide web service for DirecTV/AT&T (Java/Spring Boot, Couchbase, Elasticsearch).

VietSoftware International — Software Engineer

May 2012 – June 2014

Built an enterprise service bus for Alliance Bernstein (UK) and a foreign exchange management system for BIDV bank.

Education

Bachelor of Engineering, Information Technology

Post and Telecommunication Institute of Technology, Hanoi

Training

Essential DDD — Paul Rayner