Senior Mobile & Kotlin Engineer — .NET Backend

I build reliable, high-performance mobile and backend systems across Kotlin Multiplatform and .NET, with a focus on reactive programming, concurrency, software architecture, and performance. I'm an RxDart maintainer and open-source contributor.

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Since 2018Shipping mobile software RxDart maintainerRepository-wide CODEOWNER FlowExt authorKMP library · 400+ GitHub stars Merged upstreamFlutterFire · Koin · Khonshu · Google Ground 1k+ GitHub starsMVI-Coroutines-Flow · author & maintainer

Selected work

Engineering work, with the proof attached.

Libraries, cross-platform applications, upstream fixes, and backend systems — each framed by the problem, engineering decisions, and verifiable evidence.

Active library

Reactive systems

FlowExtAuthor & maintainer

Kotlin Multiplatform operators and extensions that fill practical gaps in kotlinx.coroutines Flow.

Problem: Flow's compact core leaves production apps without several familiar reactive operators, but extensions must preserve structured concurrency.
Architecture & trade-off: Build focused Flow extensions instead of a parallel abstraction; adoption stays lightweight at the cost of cross-platform semantic tests and careful cancellation handling.
Result / evidence: Published on Maven Central with versioned docs, common tests, CI, and 400+ GitHub stars.

KMP
Coroutines
Flow
Concurrency
Testing

Source Docs Technical article

Maintained sample

Android architecture

MVI-Coroutines-FlowAuthor & maintainer

A multi-module Android reference for unidirectional state, Kotlin Coroutines Flow, and testable Clean Architecture.

Problem: Reactive Android features need deterministic state and event handling without coupling UI, domain, and data concerns.
Architecture & trade-off: Separate feature, domain, data, and MVI infrastructure modules; model intents, immutable state, and one-shot events with Flow. Explicit boundaries improve testability while adding contracts and module plumbing.
Result / evidence: 1k+ GitHub stars, tagged releases, extensive ViewModel, domain, and data tests, plus dedicated build and unit-test workflows.

Android
MVI
Coroutines
Flow
Clean Architecture
Testing

Source Tests Releases Compose companion

Architecture sample

KMP application

GitHub Search KMMAuthor

An end-to-end GitHub search app with Jetpack Compose on Android and SwiftUI on iOS.

Problem: Share behavior and state across Android and iOS without forcing both products into a shared UI layer.
Architecture & trade-off: Share domain, data, presentation, and ViewModel layers while keeping Compose and SwiftUI native; accept duplicated UI and platform integration.
Result / evidence: Android and iOS CI, shared tests, documented architecture, and 200+ GitHub stars.

KMP
Jetpack Compose
SwiftUI
MVI
Clean Architecture

Source Architecture CI

Merged upstream

Open source

Selected upstream contributionsContributor

Production fixes and performance work accepted into established mobile and Kotlin projects.

Problem: Fix defects inside external codebases without widening APIs or disrupting existing runtime behavior.
Architecture & trade-off: Use narrowly scoped patches — iterative traversal, keyed state restoration, explicit error paths, and corrected locking — to match each project's constraints.
Result / evidence: Changes reviewed and merged by maintainers of FlutterFire, Koin, Khonshu, and Google Ground.

Open Source
Android
Flutter
Kotlin
Concurrency

FlutterFire PR Koin PR Khonshu PR Google Ground PR

Backend practice

.NET backend

NetAuthAuthor

An educational ASP.NET Core authentication service for exploring production-minded backend design.

Problem: Authentication correctness spans domain invariants, token lifecycle, persistence, and reliable side effects.
Architecture & trade-off: Use DDD, CQRS, Clean Architecture, and a transactional outbox; explicit boundaries improve testability while adding application-layer plumbing.
Result / evidence: Unit, integration, and architecture test suites backed by CI, PostgreSQL, Redis, and OpenTelemetry.

.NET
DDD
CQRS
PostgreSQL
Security

Source Tests CI

Infrastructure demo

Data infrastructure

PostgreSQL HA labAuthor

A production-minded lab for PostgreSQL high availability with Patroni, HAProxy, and EF Core.

Problem: A primary failure or replica lag breaks naive connection routing and read-after-write assumptions.
Architecture & trade-off: Combine Patroni election, HAProxy routing, and split EF Core contexts; higher availability and read scale come with retry and eventual-consistency complexity.
Result / evidence: Runnable Docker topology, operational scripts, terminal evidence, and documented failure scenarios.

PostgreSQL
Patroni
HAProxy
EF Core
High Availability

Source Demo scenarios Technical notes

A few snapshots from Hải Lăng, Quảng Trị — my hometown.

Company
Full-time developer & Freelance / Open Source
Role
Senior Mobile & Kotlin Engineer
Date
2018 Present
Company
GoTECQ Vietnam, Ltd.
Role
Flutter Developer
Date
2020 2021

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Senior Mobile & Kotlin Engineer — .NET Backend

Engineering work, with the proof attached.

FlowExtAuthor & maintainer

MVI-Coroutines-FlowAuthor & maintainer

GitHub Search KMMAuthor

Selected upstream contributionsContributor

NetAuthAuthor

PostgreSQL HA labAuthor

Implementing a race/amb operator for Kotlin Coroutines Flow.

Clean Architecture có thực sự làm system chậm đi? Performance, complexity và những trade-off thực tế

From Kotlin to .NET Backend #1: An Entity Is More Than a Data Class

Result — flatMapError, recover và recoverWith

Work Experience

Senior Mobile & Kotlin Engineer — .NET Backend

Engineering proof

Engineering work, with the proof attached.

FlowExt· Author & maintainer

MVI-Coroutines-Flow· Author & maintainer

GitHub Search KMM· Author

Selected upstream contributions· Contributor

NetAuth· Author

PostgreSQL HA lab· Author

Implementing a race/amb operator for Kotlin Coroutines Flow.

Clean Architecture có thực sự làm system chậm đi? Performance, complexity và những trade-off thực tế

From Kotlin to .NET Backend #1: An Entity Is More Than a Data Class

Result — flatMapError, recover và recoverWith

Work Experience

FlowExtAuthor & maintainer

MVI-Coroutines-FlowAuthor & maintainer

GitHub Search KMMAuthor

Selected upstream contributionsContributor

NetAuthAuthor

PostgreSQL HA labAuthor