Hello, I'm

Shaun Alonzo

Senior .NET & AWS Engineer

I help engineering teams modernize legacy .NET systems, design cloud-native architectures on AWS, and ship with AI-augmented workflows. 10+ years building for fintech, real estate, and marketplace platforms across APAC and Australia.

Get In Touch
Shaun Alonzo

How I Can Help Your Team

.NET Modernization

Legacy .NET Framework on Windows EC2 → containerized .NET 10 on AWS ECS/EKS. Zero-downtime migrations, phased traffic routing, .NET Standard compatibility bridges. I've done this at scale — eliminated 5+ years of technical debt with zero customer impact.

AWS Architecture & Cloud-Native Design

Event-driven architectures (SQS/SNS, EventBridge), serverless (Lambda, API Gateway), container orchestration (ECS Fargate, EKS), infrastructure-as-code (AWS CDK). AWS Solutions Architect Associate certified.

AI-Augmented Engineering

I help teams integrate AI tooling (Claude Code, GitHub Copilot) into their full SDLC — from architecture design and automated test generation to code reviews. Established AI best practices later adopted across multiple squads at Domain.

Fractional Senior/Principal Engineer

Need a senior .NET/AWS engineer embedded on your team for a critical project? I step in for 3-6 months to lead architecture, mentor developers, and ship. No onboarding overhead — I've done this remotely across timezones.

Skills

Backend

C# .NET 10 ASP.NET Core Entity Framework Dapper REST APIs CQRS Microservices

AWS

ECS Fargate EKS Lambda SQS/SNS EventBridge API Gateway S3 DynamoDB CDK CloudWatch

Frontend

React TypeScript Server-Driven UI Responsive Design

Data & Caching

SQL Server PostgreSQL Redis DynamoDB Query Optimization

AI-Augmented Development

Claude Code GitHub Copilot MCP Architecture Prompt Engineering LLM API Integration

DevOps & Observability

Docker GitHub Actions ArgoCD Serilog Elastic APM CloudWatch xUnit Playwright

Work Experience

Mar 2023 - Present
Senior Software Engineer — Remote
  • Led zero-downtime modernization of mission-critical services from .NET Framework on AWS EC2 (Windows) to containerized .NET on AWS EKS, eliminating 5+ years of technical debt with zero customer impact.
  • Architected an event-driven Order Orchestration Engine using AWS EventBridge, SNS, and SQS to automate Salesforce order ingestion — eliminating manual steps from the sales pipeline and accelerating order processing.
  • Built a reusable .NET HTTP resilience library with IHttpClientFactory, automated OAuth2 token lifecycle, and configurable circuit breakers/retries — adopted across multiple squads.
  • Integrated Claude Code & GitHub Copilot into the full SDLC (architecture, coding, test generation, code review), measurably increasing team throughput sprint-over-sprint. Established AI tooling best practices later adopted across the organization.
  • Migrated legacy React/.NET Framework internal tools to Retool (no-code), freeing engineering capacity from internal CRUD maintenance to focus on core revenue-generating products.
  • Introduced end-to-end automated testing with Playwright in the build pipeline, validating critical frontend and backend user journeys on every deployment.
Nov 2021 - Mar 2023
Senior Software Engineer — Remote
  • Engineered a standardized Server-Driven UI (SDUI) framework for Editorial and Reviews pages, establishing a unified contract across Web, iOS, and Android — decoupling cross-team dependencies and reducing time-to-market.
  • Decomposed a monolithic Editorial API into separate read/write paths with Redis distributed caching (CQRS), improving scalability for consuming teams.
  • Led the Redbook.com.au frontend rewrite in React/TypeScript, driving a 20% traffic increase to inquiry pages.
  • Shipped "Can't Find Your Car" feature end-to-end, generating 200+ new ad listings within 90 days of launch.
Aug 2020 - Nov 2021
Senior Software Engineer — Pasig, PH
  • Designed SOC2-compliant public APIs with ASP.NET Core and OAuth2/JWT for third-party loan submissions in a regulated fintech environment.
  • Built .NET Framework ASP.NET MVC applications for loan product landing pages with responsive Razor views and form submission pipelines.
  • Led the MoneyMe+ WooCommerce plugin team; integration brought in 1,000+ e-commerce leads within its first 60 days.
Dec 2019 - Jul 2020
Lead Software Engineer — Pasig, PH
  • Led a cross-functional squad of 10 with full ownership of sprint grooming, technical specs, weekly releases, and on-call rotation.
  • Optimized lender API integration layer, reducing response times from 8s to 2s on a platform processing 150,000 transactions per day.

Earlier: BlastAsia (Software Engineer I → Dev Lead, 2016-2019) · Accenture (Associate SE, 2015-2016)

Featured Projects

Card Guide PH

A comprehensive guide for credit card information and tracking in the Philippines. AI agents (LLM + Playwright) for automated data extraction, React/Node.js on Vercel, PostgreSQL.

Node.js TypeScript React Vercel PostgreSQL AI Agents

Redbook Website Redesign

Led the transition of Redbook.com.au from a 2000s aesthetic to a modern design, revitalizing website appearance while maintaining existing customers and boosting website views.

C# React AWS .NET

MoneyMe+ WooCommerce Plugin

Developed an e-commerce plugin that generated over 1000 leads within first 2 months of launch, connecting sellers with financing options.

C# JavaScript Azure .NET Core WordPress

Get In Touch

I work with engineering teams — whether that's a 3-month .NET modernization sprint, AWS architecture consulting, embedding as a fractional senior engineer, or a full-time role on a mission-driven team.

Based in the Philippines (UTC+8), working remotely with teams in Australia, the UK, and the US.

Manila, Philippines
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