Facundo García Reyna, Developer in Villa Allende, Cordoba, Argentina
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Facundo García Reyna

Verified Expert  in Engineering

Software Engineer and Developer

Villa Allende, Cordoba, Argentina

Toptal member since February 27, 2025

Expertise
GolangMicroservices DevelopmentGitMacOSSlack DevelopmentGitHubMySQLTwilio DevelopmentAmazon S3DatadogAWSJiraElasticsearchJava
Bio

Facundo is an experienced software engineer with a strong background in back-end development, specializing in Go. He is proficient in designing, developing, testing, and maintaining scalable microservices and back-end solutions. His expertise spans architectural design, system thinking, migrations, and integrations, including blockchain. Facundo is also skilled in performance optimization, code quality, mentoring teammates, product development, and understanding user needs.

Portfolio

MercadoLibre
Go, Amazon DynamoDB, Cassandra, MySQL, REST, Microservices, Elasticsearch...

Experience

  • Unit Testing - 10 years
  • Microservices - 8 years
  • Performance - 8 years
  • Go - 8 years
  • REST - 8 years
  • Concurrency - 7 years
  • Architectural Design - 7 years
  • Scalability - 5 years

Availability

Full-time

Preferred Environment

MacOS, GoLand, Slack, Git, GitHub, Go, APIs

The most amazing...

...performance improvement I've done is refactor a 19-hour process by implementing concurrency with 100,000+ goroutines, reducing execution time to 22 minutes.

Work Experience

Software Engineer

2018 - 2020
MercadoLibre
  • Refactored a 19-hour process implementing a concurrency pattern with over 100,000 goroutines, reducing the execution time to 22 minutes.
  • Improved the stability of hundreds of microservices by implementing a circuit breaker tool to be used by several teams.
  • Implemented a 206 Partial Content response code in the most critical service of the company with 25 million requests per minute, a 10-millisecond response time, and 99.98% uptime, reducing unnecessary retries.
  • Discovered and fixed a memory leak in a critical service the team was restarting every night to prevent failures using buffered channels.
  • Migrated legacy services in Java or Grails to Go and helped other teams to do it with their services.
  • Collaborated in a specialized team working on improving the on-call experience for team members.
  • Participated as a speaker in several tech talks and Go meetups.
  • Engaged in a project with Universidad Blas Pascal, a local university where a few engineers taught Go and best practices to students.
Technologies: Go, Amazon DynamoDB, Cassandra, MySQL, REST, Microservices, Elasticsearch, Apache Pulsar, Redis Cache, Amazon S3 (AWS S3), Datadog, New Relic, Kibana, Opsgenie, Twilio API, Git, GitHub, Jira, Concurrency, Scalability, Architectural Design, Unit Testing, Readability, Java, Grails, APIs, Goroutines

Experience

List Sorting API at MercadoLibre

A Go microservice that allows teams to tag items in real time and generates a dump of data to be used by an eCommerce platform's filtering and sorting service. The store tag flow had a high error rate, and the dump generation process took more than 19 hours. I redesigned the models and the way data was stored and refactored the dump generation process using over 100,000 goroutines. The process ended up taking only 22 minutes.

Skills

Libraries/APIs

Twilio API

Tools

GoLand, Slack, Git, GitHub, Kibana, Jira

Languages

Go, Java

Paradigms

REST, Microservices, Unit Testing

Platforms

MacOS, Opsgenie, New Relic, Blockchain

Storage

Amazon DynamoDB, Cassandra, MySQL, Redis Cache, Amazon S3 (AWS S3), Datadog, Elasticsearch

Frameworks

Grails

Other

Concurrency, Readability, Performance, Apache Pulsar, Architectural Design, Scalability, APIs, Goroutines, Crypto, Cryptocurrency

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