Slideshow 1: Dao Duc
Dao DucBackend / Full-stack Engineer · Technical Lead

I build lean, readable, durable products.

Backend-focused full-stack engineer experienced in team leadership, distributed system design, API development, performance optimization, and taking products from discovery to production.

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Selected work

Jul 2023 - Present

Internal Developer Platform

Internal Developer Platform, Image 1Image 1 of 3

Technologies

  • Backstage
  • TypeScript
  • Kubernetes
  • Argo CD
  • Terraform
  • GitHub Actions
  • Prometheus
  • Grafana

Engineering Lead

Self-service portal providing service templates, standardized CI/CD, environment management, secrets, and a system catalog.

Reduced product-team toil, standardized operations, and enabled engineers to create safe new services in minutes.

Achievements

  • Reduced new-service setup from three days to 20 minutes.
  • Increased average deployment frequency by 2.4 times.
  • Reduced configuration-related incidents by 41%.

Sep 2024 - Jun 2025

AI Customer Support Assistant

AI Customer Support Assistant, Image 1Image 1 of 3

Technologies

  • Next.js
  • Python
  • FastAPI
  • PostgreSQL
  • pgvector
  • OpenAI API
  • Redis
  • Docker

Technical Lead

Agent-assist tool for knowledge retrieval, conversation summarization, and source-backed response drafting.

Reduced handling time while keeping human approval before sending, limiting incorrect-response risk.

Achievements

  • Reduced average handling time by 32%.
  • Reached 91% valid source citations on the internal evaluation set.
  • Reduced new-agent onboarding time by 38%.

Jan 2024 - Dec 2024

Omnichannel Commerce Platform

Omnichannel Commerce Platform, Image 1Image 1 of 3

Technologies

  • Next.js
  • TypeScript
  • NestJS
  • PostgreSQL
  • Redis
  • RabbitMQ
  • Docker
  • AWS

Technical Lead · Full-stack

Unified storefront, point-of-sale, inventory, ordering, promotions, and fulfillment platform for a multi-branch retailer.

Enabled near-real-time inventory visibility, reduced cancellations caused by stock drift, and shortened feature delivery cycles.

Achievements

  • Sustained 3,000 orders per hour during peak campaigns.
  • Reduced checkout API p95 from 1.8 seconds to 420 ms.
  • Reduced stock-drift incidents by 60% using reservations and reconciliation jobs.

Mar 2023 - Feb 2024

Digital Wallet and Transaction Ledger

Digital Wallet and Transaction Ledger, Image 1Image 1 of 3

Technologies

  • Java
  • Spring Boot
  • PostgreSQL
  • Kafka
  • Redis
  • Kubernetes
  • OpenTelemetry

Backend Lead

Wallet services supporting deposits, withdrawals, transfers, refunds, reconciliation, and transaction limits.

Created an auditable money flow, prevented duplicate posting, and automated reconciliation across payment partners.

Achievements

  • Reached 99.99% reconciliation accuracy.
  • Reduced end-of-day reconciliation from three hours to 18 minutes.
  • Recorded zero duplicate postings across more than 12 million retried requests.

Jun 2022 - Aug 2023

Real-time Logistics Control Tower

Real-time Logistics Control Tower, Image 1Image 1 of 3

Technologies

  • React
  • Node.js
  • Go
  • Kafka
  • PostgreSQL
  • PostGIS
  • ClickHouse
  • WebSocket

Lead Full-stack Engineer

Operations dashboard for shipment dispatching, driver tracking, SLA-risk alerts, and route optimization across multiple hubs.

Gave dispatchers network-wide visibility, accelerated exception handling, and reduced unnecessary delivery distance.

Achievements

  • Processed 8,000 location events per second.
  • Reduced response time for at-risk shipments by 22%.
  • Reduced average distance per delivery by 14%.

Jan 2022 - Dec 2022

Healthcare Booking and Telemedicine Platform

Healthcare Booking and Telemedicine Platform, Image 1Image 1 of 3

Technologies

  • Next.js
  • Node.js
  • TypeScript
  • PostgreSQL
  • Redis
  • WebRTC
  • Docker

Senior Full-stack Engineer · Team Lead

Doctor discovery, appointment booking, reminders, video consultation, and visit-record management for multi-site clinics.

Reduced call-center load, improved appointment attendance, and standardized clinic intake workflows.

Achievements

  • Handled 120,000 bookings in the first year.
  • Reduced manual booking calls by 35%.
  • Improved appointment attendance from 72% to 86%.

May 2021 - May 2022

SaaS Subscription and Billing Platform

SaaS Subscription and Billing Platform, Image 1Image 1 of 3

Technologies

  • Node.js
  • TypeScript
  • PostgreSQL
  • BullMQ
  • Redis
  • Stripe
  • Docker

Backend Engineer · Acting Lead

Plan, trial, upgrade, downgrade, usage-based billing, invoicing, and payment-webhook management.

Let product teams test pricing models without rewriting core payment logic for every new plan.

Achievements

  • Automated 95% of recurring invoicing.
  • Reduced billing support issues by 48%.
  • Shortened new pricing-plan delivery from two weeks to two days.

Aug 2020 - Sep 2021

Real-time Document Collaboration Suite

Real-time Document Collaboration Suite, Image 1Image 1 of 3

Technologies

  • React
  • TypeScript
  • Node.js
  • WebSocket
  • Redis
  • PostgreSQL
  • CRDT

Full-stack Engineer

Concurrent document editing, comments, mentions, presence, and version history for distributed teams.

Kept concurrent edits merging without conflict, reduced content collisions, and supported safe version recovery.

Achievements

  • Supported 50 concurrent editors per document.
  • Kept synchronization p95 below 180 ms.
  • Reduced average payload size by 40% through delta compression.

Feb 2020 - Mar 2021

Enterprise Data Integration Hub

Enterprise Data Integration Hub, Image 1Image 1 of 3

Technologies

  • Python
  • FastAPI
  • Kafka
  • Airflow
  • PostgreSQL
  • S3
  • Kubernetes

Backend Lead

Configurable data pipelines connecting CRM, ERP, data warehouses, and partner systems.

Replaced fragmented cron jobs with observable, retryable integrations and centralized schema governance.

Achievements

  • Processed 45 million records daily.
  • Reduced pipeline incident investigation by 70%.
  • Raised on-time job completion to 99.7%.

Apr 2019 - Jun 2020

Central Identity and Access Management

Central Identity and Access Management, Image 1Image 1 of 3

Technologies

  • Go
  • OAuth 2.0
  • OpenID Connect
  • PostgreSQL
  • Redis
  • Kubernetes
  • Vault

Senior Backend Engineer

Central login, SSO, MFA, session management, and authorization services for an enterprise application ecosystem.

Standardized authentication, reduced fragmented accounts, and improved access governance.

Achievements

  • Migrated 14 applications serving 85,000 accounts.
  • Reduced password-reset tickets by 75%.
  • Enabled global session revocation in under 10 seconds.