Build
Backend and distributed systems, cloud infrastructure, and repeatable software delivery. At DSS, this included Onramp deployment foundations and Temporal-based order lifecycle orchestration.
Ho Chi Minh City, Vietnam
Phylicia Huynh / Senior Backend Software Engineer
Reliable systems.
Practical decisions.
Building backend systems, improving how teams deliver software, and making technical decisions grounded in business needs and available resources.
12+ yearsSoftware engineering
Go & distributed systemsBackend architecture and production
Vestiaire CollectiveCurrent / Senior Backend Engineer
01 / Approach
Engineering with
the whole problem in view.
Senior Backend Software Engineer with 12+ years in software engineering across commerce, logistics, and advertising. My work spans backend services, workflow orchestration, and deployment infrastructure. I focus on changes that meet the business need with appropriate correctness, recovery, and operating costs. AI-assisted workflows help me carry related work across the stack, with review and testing built into delivery.
Operate
Workflow reliability, observability, production investigations, and release readiness. Connect application behavior to data, infrastructure, and maintenance constraints.
Evolve
Improve mature systems with solutions proportionate to business risk and cost. Use AI-assisted development across the stack while remaining accountable for correctness and testing.
02 / Selected work
Architecture in practice.
Selected contributions.
Real systems, real constraints.
Applied computer vision
Vestiaire Collective
From authenticity research to duplicate-listing detection
The work began as a proof of concept using Vestiaire Collective data to explore the likelihood that an item is authentic or counterfeit. It has since expanded into a new project to identify duplicate listings, with the aim of improving marketplace supply.
I initially supported infrastructure and CI/CD for the POC, then took on implementation of near-match photo detection in Python using PDQ perceptual hashes and DINOv2 embeddings. This is what draws me to the project: turning an exploratory idea into a practical tool for finding duplicate listings.
Workflow architecture
Vestiaire Collective
Planning workflow modernization around real constraints
Developed a phased modernization proposal for an aging Conductor platform, starting with business workflows, operational pain points, engineering capacity, and migration risk.
Evaluated Conductor and Temporal, managed versus self-hosted operation, migration continuity, effort, and long-term maintenance cost. Leadership accepted the proposal; implementation planning and intake are underway.
Platform foundations
Digital Signal Service / Highlands Coffee
Onramp: rebuilding the delivery foundation
Contributed to rebuilding application deployment infrastructure and CI/CD with Azure DevOps, GKE, Terraform, Helm, and Helmfile, making service delivery more repeatable.
This work expanded my hands-on infrastructure and deployment responsibilities alongside backend development, with development workflows and technical documentation supporting the delivery foundation.
Engineering practice
Vestiaire Collective
Expanding ownership beyond the backend
Make the most of AI agents by delegating repetitive work and building reusable skills that capture system context and guide debugging with minimal repeated instructions. Apply these workflows to frontend changes, Cypress tests, Python services, and Conductor's Java implementation.
Work with AI as a thinking partner: clarify ideas one question at a time, challenge assumptions, explore tradeoffs, and keep an evolving design document in sync. I review the implementation and remain accountable for technical decisions, testing, and correctness.
Order fulfillment
Vestiaire Collective
Connecting marketplace orders to fulfillment
Delivered the order and fulfillment integration for Zalando, connecting marketplace orders to reservations, inventory, and per-order-line workflows.
Covered fulfillment documents, operational notifications, error handling, and coordination with business and operations teams. The launch had no significant order-side implementation issues attributable to this work.
Pragmatic architecture
Vestiaire Collective
Keeping architecture proportional to the problem
Improve established order and fulfillment systems incrementally within the existing PHP/Symfony, Kafka, and workflow ecosystem, using existing infrastructure where it meets the need.
Assess consistency needs, failure consequences, recovery paths, effort, and operating cost. Payment and inventory invariants need strong correctness guarantees; lower-risk operations may allow best-effort handling with recovery.
03 / Technical expertise
Depth in the backend.
Context across the stack.
- Languages
- Go, PHP, SQL
- Backend & architecture
- Distributed systems, microservices, event-driven architecture, REST, gRPC
- Workflow orchestration
- Conductor (VC production), Temporal (DSS order lifecycle; VC evaluation)
- Data & messaging
- Kafka, MySQL, MariaDB, PostgreSQL, Redis, Elasticsearch
- Cloud & delivery
- Kubernetes, GCP/GKE, AWS RDS, Terraform, Helm, Helmfile, Azure DevOps, CI/CD
- Testing & reliability
- Unit testing, Cypress, distributed tracing, Datadog, Grafana, Kibana
- AI-assisted engineering
- Reusable agent skills, codebase investigation, implementation and test automation
04 / Experience
From backend foundations
to broader ownership.
Vestiaire Collective
Senior Backend Engineer
Order fulfillment, workflow operations, and cross-stack delivery
- Modernize PHP/Symfony and Kafka order flows incrementally, preserving compatibility and weighing implementation cost against operational risk.
- Implemented Zalando order and fulfillment workflows end to end, coordinating delivery with business and operations teams.
- Operate Conductor in production, troubleshooting task execution, workflow retention, and MariaDB/RDS behavior.
- Developed a leadership-accepted workflow modernization plan after evaluating Conductor, Temporal, and hosting options; implementation planning is underway.
- Build reusable agent skills for system investigation and repetitive implementation; deliver related frontend, Python, and Java work with code review and Cypress validation.
- Expanded from POC infrastructure and CI/CD support to implementing near-match photo detection in Python with PDQ and DINOv2 for a duplicate-listing project.
Ninja Van Tech Lab
Senior Software Engineer
Mart business unit / Distribution to small grocery stores
- Designed and delivered Go services for grocery distribution in the Mart business unit, coordinating teams around Kafka, MySQL, and Elasticsearch solutions.
- Raised unit-test coverage across Mart BU services from approximately 25% to 70%; strengthened dashboards, monitoring, and alerting.
- Mentored engineers through design and implementation feedback, and planned feature rollouts to avoid downtime and user impact.
Digital Signal Service Co., Ltd
Senior Backend Engineer
Onramp infrastructure and Highlands Coffee digital platforms
- Contributed to the Onramp deployment infrastructure rebuild with Azure DevOps, GKE/Kubernetes, Terraform, Helm, and Helmfile.
- Established backend development and delivery practices, technical documentation, and guidance for engineers building internal platforms.
- Adopted Temporal for order-lifecycle orchestration and implemented a state machine handling approximately 10x the previous production order volume.
- Delivered Store/Kitchen backend services used across Highlands Coffee stores for order processing and restaurant operations.
- Connected ShopeeFood, Zalo, and GrabExpress to internal ordering and operational workflows using Go and PostgreSQL services.
Grab
Backend Engineer to Senior Backend Engineer
Advertising platforms
- Built multi-currency support for the ads management platform and delivered a merchant self-service advertising platform.
- Built targeting-query configuration for non-technical advertising operators.
- Improved reliability around unstable third-party dependencies in Go/MySQL microservices and distributed data flows.
Sendo Technology Joint Stock Company
Backend Engineer
E-commerce services
- Maintained a large PHP monolith and progressively migrated functionality into Go microservices, including checkout and product services.
- Built Salesforce integration and message-broker functionality within an e-commerce stack using MongoDB, Redis, and Elasticsearch.
Earlier experience
YouNet Joint Stock Company
Web Developer
Oct 2013 - Jun 2017
Customized PHP/SocialEngine products with Zend Framework and MySQL, translating customer requirements into implementations and coordinating delivery.
BeyondEdge Pte Ltd
Web Developer Intern
Oct 2012 - Jun 2013
Developed and customized PHP/Joomla plugins for customer websites.
Education
Bachelor of Information Technology
Hoa Sen University · 2009 - 2013
05 / Connect
Engineering is
a conversation.
For conversations about backend systems, workflow orchestration, and the practical decisions behind reliable software.
hal.hndanphuc@gmail.com