Tran Quy Doan

Embedded fintech and card-issuing platform serving multiple white-label clients (mobile banking, instant payouts, KYC). Frontend lead with full-stack reach across Python services and PostgreSQL.

• Multi-tenant frontend architecture. Designed a layered Nx monorepo with a shared core UI (themeable via design tokens) and a two-tier API client — a granular per-endpoint layer with consistent error handling, and a business-service layer where per-client logic diverges. ~30% reduction in duplicated code across client apps.
• PostgreSQL across the stack. Schema design and migrations for new client onboarding flows, query tuning when card-state reads got expensive, and joining backend engineers on data-shape decisions the frontend would consume.
• Python security & feature work. Identified and remediated critical vulnerabilities in shared Python services that could have led to account compromise; occasional feature work alongside the primary backend team.
• AI-augmented delivery, with measured outcomes. Introduced AI tooling (Claude Code, Copilot, prompt/context guides) and convinced leadership to license it across the team:
  • Animated landing page delivered in <1 week against a 3+ week estimate.
  • Vue 2 → Vue 3 migration completed in ~1 week after a 4–5 month effort had stalled.
  • Repetitive multi-client feature work compressed from days to hours via reusable libs + AI-driven edits.
  • Sustained team throughput at ~2 features/day with proper review.
• Hiring & team scaling. Led the senior React interview pipeline; built an internal tool that generates real-world React coding problems on demand, evaluating candidates on reading unfamiliar code over memorised patterns.
• Test automation foundation. Stood up the frontend test framework (Vitest + Playwright in the Nx monorepo); coverage now ~80%, deployment cycles meaningfully shorter.

Rails backend services running on Kubernetes via Concourse CI.

• Diagnosed a server-uptime regression shortly after joining — root cause was PostgreSQL row-level locking under a recently changed migration pattern. Fixed the contention and added preventative monitoring.
• Killed a recurring DST toil item by moving the seasonal adjustment to a database-level fix, independent of the surrounding services — permanently retired a manual quarterly process.
• Release-notes + image-build automation. Built a Ruby library that generated release notes from commit/PR metadata and produced container images as part of the Concourse pipeline, removing daily manual steps.
• Regularly paired with frontend engineers on debugging and integration issues across the stack.

Digital signage and out-of-home media platform on Rails, deployed across BrightSign, Samsung Tizen, LG webOS, and Electron.

• Rails backend powering the multi-device platform — content scheduling, device management, widget marketplace APIs, and the data model behind the cross-device player runtime.
• Cross-device framework with layered architecture for digital signage apps; cut new-app delivery from months to 2–3 weeks (~50% time saved) by isolating device-specific code from shared business logic.
• Internal "app store" for digital signage widgets. Designed an SDK for publishing widgets and an internal marketplace where the team browses, configures (style, colors, content), and ships to devices — turning a developer-bottlenecked custom-dev workflow into self-serve configuration.
• Hardware-free mask detection for in-store screens using TensorFlow.js in the browser — avoided per-store camera deployments while still triggering compliance alerts.
• Vancouver Metro app built on GTFS data, deployed across stations — a contractually meaningful piece of the client engagement.
• OpenShift migration + security hardening to meet bank-level compliance, unlocking enterprise contracts.

Founded and led a small Rails-shop outsourcing studio. Notable clients: Angkas (motorcycle ride-hailing, Philippines), Avenue28 (real estate investment), Art Loft Asia (art marketplace). Day-to-day mix of Rails architecture, hands-on delivery, and client management.

• Led a 5-developer Rails team through full SDLC for the Art Loft Asia platform connecting artists and collectors.
• Auto-scaling infrastructure with AWS CloudFormation + Chef Solo to scale EC2 down off-peak: ~20% server cost reduction with no impact on peak performance. (2011–2012 — well before managed autoscaling was a default.)
• Real-time bidding component as a separate service over WebSocket (Socket.io + Node.js + Redis), decoupled from the Rails monolith so it could scale independently and respond in <500ms.

• Ruby Developer — Ndex (HCMC, 2010–2011), Frexo (Bangkok, 2009–2010), Clearpath (HCMC, 2008–2009). Rails-focused product work across three markets.
• Java Developer — Mobile Solution Service (HCMC, 2006–2008). First professional role; where the JavaScript and MySQL years started, alongside Java/PHP backend work.