Gabriel Galarza

Lead Software Engineer · AWS serverless and C#/.NET · Remote (ET)

I’ve spent 15+ years building software for billing and payments: ASP.NET monoliths, then .NET Core services, now serverless on AWS. I lead teams, set the architecture, and stay in the code.

hello@gabriel-g.com

Selected work

Serverless payments platform

ASP.NET billing monolith to .NET services on AWS Lambda

The platform was one ASP.NET app on SQL Server. I migrated it to .NET microservices on Lambda behind API Gateway. Millions of dollars a month in transactions ran through it.

  • AWS Lambda
  • API Gateway
  • .NET Core
  • SAM
  • CloudFormation
  • SQS
  • S3

Document centralization and payment provider integrations

Serverless document repository exposed to third-party payment providers

Built from scratch: Angular on the front end, .NET services on Lambda behind API Gateway. It centralizes document repositories fed by several business units in the organization and exposes them to third-party payment providers.

  • Angular
  • .NET
  • Lambda
  • API Gateway
  • S3
  • Cognito

AI invoice search

Search over vendor invoices in S3 with an Amazon Bedrock Knowledge Base

Hundreds of vendor invoices were sitting in S3 with no way to search them. I set up an Amazon Bedrock Knowledge Base over the bucket so they can be queried with AI models.

  • Amazon Bedrock
  • Knowledge Bases
  • S3
  • Lambda

Experience

Three billing and payments companies over 15+ years, from ASP.NET to serverless on AWS.

  1. –present

    Lead Software Engineer

    Electronic billing platform · Remote

    I was tasked with modernizing the legacy billing stack and reducing infrastructure costs. That turned into rebuilding the architecture and leading the team. I still write code.

    • Rebuilt the payment APIs on Lambda, API Gateway, and .NET.
    • Designed and shipped a serverless document-ingestion app end to end with Angular, .NET, API Gateway, SAM, and CloudFormation.
    • Designed and shipped marketplace APIs that clients use to manage communications and documents.
    • Built document search on Amazon Bedrock Knowledge Bases over documents in S3.

  2. –

    Senior Software Engineer

    B2B invoicing and payments platform · Remote

    Modernized legacy ASP.NET MVC apps into .NET Lambda microservices on AWS.

    • Migrated on-prem services to AWS.
    • Worked in ASP.NET Core, Angular, Azure DevOps, and SQL Server.

  3. –

    Software Engineer

    Global e-invoicing platform · Remote

    Seven years on a platform that enterprise clients worldwide used to automate billing presentment and payment.

    • Built tools that automated parts of invoice presentment and reconciliation.
    • Tuned SQL Server queries and backend APIs in ASP.NET MVC and C#.

Stack

Languages
C#, SQL, TypeScript, JavaScript
Frameworks
ASP.NET, .NET, Angular
AWS
Lambda, API Gateway, SQS, S3, Cognito, SAM, CloudFormation, Bedrock
AI
RAG pipelines, Bedrock Knowledge Bases, prompt engineering
Databases
SQL Server, Aurora
Practice
Architecture, team leadership, mentorship, performance work, legacy migrations

Contact

Email: hello@gabriel-g.com

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