Rodolfo is available for hire

Rodolfo Luis Leyes

Verified Expert in Engineering

Full-stack Developer

Córdoba, Cordoba, Argentina

Toptal member since April 23, 2015

Expertise

SQL Linux GitHub Git Ruby on Rails (RoR)Heroku PostgreSQL Ruby Subversion MySQL RSpec REST APIs Bitbucket SSL SOAP Android NDK Linux CentOS Intercom HAML JUnit Solaris Arduino

Bio

Rodolfo is a highly motivated, self-driven developer with over 15 years of experience. He started learning software programming in his early youth, learning basics from a book and playing around with an old 8086 PC. He is a professional who looks forward to working on high-quality projects. Rodolfo prides himself in his ability to dig and solve problems quickly.

Portfolio

GetYourPlace Group

Ruby on Rails (RoR), Heroku, React, ActiveAdmin

Upsider, Inc.

Ruby on Rails (RoR), React

Distribution Publications

Mailchimp API, Solr, Capistrano, AWS Lambda, Amazon S3 (AWS S3), Amazon EC2...

Experience

Linux - 16 years Heroku - 10 years Ruby on Rails (RoR) - 10 years Amazon Web Services (AWS) - 7 years JavaScript - 7 years Docker - 6 years React - 4 years GraphQL - 3 years

Availability

Part-time

Preferred Environment

Visual Studio Code (VS Code), Git, Bash, Linux

The most amazing...

...thing I've coded is a data charging feature that, along with an aggressive commercial campaign, allowed a mobile operator to increase its revenue dramatically.

Work Experience

Full-stack Ruby on Rails Developer

2019 - PRESENT

GetYourPlace Group

Implemented a new testimonial showcasing feature for the main landing page part of the Ruby on Rails (RoR) web app.
Performed a complete restyling of the emails generated by the RoR app.
Upgraded several components, namely Heroku stack, database version, RoR, and Ruby interpreter version.
Validated and analyzed potential issues related to updates from 3rd-party providers. Proactively corrected settings.
Performed improvements on the multi-language set up relying on the relational database and using low-level caching. Reduced the size of the rendered HTML response.

Technologies: Ruby on Rails (RoR), Heroku, React, ActiveAdmin

Full-stack Developer

2021 - 2022

Upsider, Inc.

Downsized a monolithic Ruby on Rails (RoR) application and upgraded the remaining part from version 5 to 7.
Took ownership of the email sending and receiving process that was in charge of delivering more than 100,000 emails a day.
Implemented SMTP/IMAP interfacing alternative and improved the current in-place API method of interfacing with the different email provider services.
Migrated back-end API functionality from the monolithic RoR app into the newer smaller microservices Go app.
Analyzed a security audit report of the vulnerabilities detected on the API layer and implemented security measures to prevent these risks.

Technologies: Ruby on Rails (RoR), React

Full-stack React, Vanilla JS, and Ruby on Rails Developer

2018 - 2021

Distribution Publications

Took over the maintenance and further development of the established Ruby on Rails web app, which had an on-premises infrastructure.
Incorporated Solr indexing and search capabilities on the rates information to be used on a newly defined search screen. Current searches and other logic rely heavily on Memcached, which are not entirely well suited for this.
Automated and replaced a complex task using Excel macros to transform an XLS file into a well-formatted one to be uploaded to the app. This was replaced with a new in-app feature that does the XLS analysis and validation in the Ruby on Rails app.
Implemented New Relic and Rollbar wrapping custom app-level errors sent using email, which is now tracked there. Configured alerts and thresholds to receive notifications of unusual circumstances.
Replaced a Ruby script that monitored and sent warnings about the site being down with a New Relic synthetics monitor.
Coded and set up two Node.js and AWS Lambda functions to shut down and power on two EC2 instances used as staging environment to help reduce costs.
Programmed the complete set up of bare CentOS 7 servers into the full-blown app using Capistrano. The set up includes systemd services, Nginx, Memcached, Redis, Java Runtime, Sidekiq, cron tasks, Oracle libraries, and Puma.
Integrated Mailchimp API with the Ruby on Rails app and migrated the complete base of subscribers and their preferences. Added screens to allow users and admins to change their email preferences from inside the app.
Implemented Netdata servers monitoring and implemented server metrics alarms posting to Slack.
Migrated the complete on-premises servers infrastructure to a world-leading cloud platform. Planned, prepared, and executed a load testing scheme to properly decide the required servers' specs.

Technologies: Mailchimp API, Solr, Capistrano, AWS Lambda, Amazon S3 (AWS S3), Amazon EC2, Sidekiq, Redis, Memcached, React, jQuery, Ruby on Rails (RoR), Oracle

Full-stack React and Ruby on Rails Developer

2019 - 2020

Concierge LLC

Implemented integration with Shopify for the organizations the app managed so that each one could authorize the app to access all of their products, clients, orders, and draft orders. Syncing was performed using Webhooks and API calls.
Instituted Google OAuth authentication for users under an organization using G-Suite for sign up and sign in.
Incorporated the Google Pub/Sub flow to enable the app to receive and intercept all incoming and outgoing emails from a Gmail account that authorizes it.
Developed a back-end GraphQL API to replace the existing one in REST. The first complex GQL query was for advanced search capabilities coded, relying on Elasticsearch.
Implemented Stripe API integration to allow charging of an existing order on Shopify.
Incorporated Elasticsearch to enable the app to be able to perform complex queries.

Technologies: RSpec, Heroku, Stripe API, Shopify API, REST, GraphQL, Elastic, React, Ruby on Rails (RoR)

React/Ruby on Rails Developer

2017 - 2019

Movements, Inc.

Configured a Heroku pipeline for the RoR back-end app and isolated test apps built out of GitHub pull requests.
Implemented several API requests to provide new functionality to the iOS app.
Added new pages for the React Admin panel to support the new features on the back end.

Technologies: Heroku, Ruby on Rails 5, React

Ruby on Rails Developer

2017 - 2018

Bushel

Integrated Braintree's marketplace functionality into the platform to support invoicing.
Set up a Kanban workflow using GitHub Project.
Configured Heroku pipelines for the app for autodeploy and isolated test apps built from pull requests.
Added a web admin access only portal using ActiveAdmin with the addition of customized actions.
Implemented a geocoding feature using Google Maps API for the app to be aware of both gardens' and gardeners' proximity.
Integrated AWS S3 storage service for user uploaded content.
Implemented AWS CloudFront service for the serving of static app assets such as images, CSS, and JS files.
Defined a stylish company email design for all outgoing emails from the app to customers.
Configured Sendgrid as the outgoing mail provider.
Set up proper HTTPS certificate settings as provided by LetsEncrypt trough Heroku.
Defined a pre-production "staging" environment on Heroku.
Integrated and customized Intercom chat service.
Coded a complete invoicing scheme that allows gardeners to submit their worked effort, material costs and have garden owners be notified and able to pay using their credit card or bank account.

Technologies: New Relic, Heroku, PostgreSQL, Ruby on Rails 5

Ruby on Rails Lead Developer

2015 - 2017

Artistsignal

Configured an isolated AWS stack of virtual servers. Their software components needed to have a staging public service for development purposes.
Migrated their core Ruby on Rails 3 application to Ruby on Rails 4. Updated the Solr search server to the latest stable version.
Collaborated on migrating the application's admin panel features into the styling of a purchased admin template.
Traveled to the USA to meet the investors and the team in preparation for the launching of the beta version of the app.
Implemented a PayPal recurring billing service through an API for the app to support monthly paid subscription plans.
Built a complete integration procedure for admin users to embed custom-built sliders using a third-party UI slider designer app. Integrated a new functionality showing a live feed of the latest logins and new users.
Incorporated an in-home analytics solution backed in MySQL using the open-source Piwik (now Motomo) analytics server. Added custom tracking of app-specific events such as play, pause, and skip for songs.
Assembled a spare physical server to host several virtual machines like FreeNAS for storage and sharing, Windows 7, and Linux-based servers. The physical server was configured with vSphere ESXi.

Technologies: Elastic, MySQL, Docker, VMware vSphere, Solr, Bootstrap, Amazon ElastiCache, Relational Database Services (RDS), Amazon Simple Notification Service (SNS), Amazon CloudFront CDN, Amazon S3 (AWS S3), Amazon EC2, Ruby on Rails (RoR)

Ruby on Rails Developer

2015 - 2016

Learn To Be, a Non-Governmental Organisation

Supplemented new features to the learntobe.org online tutoring platform.
Developed an internal student-to-tutor chat feature on the web app using Slack API and private channels behind the curtains.
Coded an alternative to existing SMS notifications for tutors. The new method uses a Slack bot integration to notify each tutor registered on the organization's Slack space.
Added some more student-tutor actions to be used when they are both engaged in a tutoring lesson and when they are sharing the virtual dashboard.

Technologies: Sideqik, Slack API, PostgreSQL, Redis, jQuery, Heroku, Ruby on Rails (RoR), Ruby

Full-stack Angular/Rails Developer

2015 - 2015

Doublebit Consulting (via Toptal)

Contributed to the construction of an Angular front-end app from scratch, starting with an existing web design and a working Rails REST web service.
Defined a design on how to integrate the back-end to manage appointments using Google Calendar API.
Coded a client-side JavaScript feature to enable the web app to generate an download a ZIP file out of a collection of pictures instead of doing the ZIP file generation on the back-end.

Technologies: Bootstrap, Heroku, Ruby on Rails (RoR), Ruby

Rails Developer

2015 - 2015

Phoenix Media (via Toptal)

Solved an urgent issue regarding credit card requests being rejected when sent via ActiveMerchant gem to the Authorize.Net payment gateway.
Solved an issue regarding mail that had stopped being sent from the Rails app to customers.
Developed a script to export customer information from the database into an Excel sheet.

Technologies: ActionMailer, Delayed Job, Ruby on Rails (RoR), Ruby

Rails Developer

2015 - 2015

Fairtech Labs (via Toptal)

Implemented CORS handling on a Rails back-end.
Solved an issue with the Cordova-based Android app not being able to issue requests to the RoR back-end after subdomains were set up.
Implemented "remember me" functionality for login.

Technologies: Cordova, Ruby on Rails (RoR)

Team Leader and Ruby on Rails Web Developer

2011 - 2015

Deviva

Upgraded some of the most featured and interaction-rich functionalities to use AngularJS. I also developed unit tests using Teaspoon to be fed into the TDD cycle.
Engineered and built an application-specific theme based upon the artwork created by a graphic designer for the brand; the styles were made using Bootstrap 3.
Led a small team of part-time developers to build the required functionalities prioritized by the product owners and myself, which were then fed into an Agile behavior-driven development cycle.
Interpreted the ideas of two senior tax accountants and built a software project that started back in 2011 and was later presented and funded by the Argentinian government agency that encourages the development of software companies.
Designed, planned, developed, and led a team to build the web-based application using Ruby on Rails. The app guides accountants of export companies by selecting the information required by the government for enterprise VAT refunds.
Built reports using a Java-based JasperReports engine and integrated these into the web application. Investigated the use of a jsreport server for future use.

Technologies: Java, Ubuntu Server, RSpec, Cucumber, PostgreSQL, jQuery, Ruby on Rails (RoR)

Senior C++ Developer

2008 - 2015

America Movil

Developed multiple currency support for the core online C++, ACE, and CORBA charging and tariffing service.
Implemented a Git versioning scheme tied to a CVS working copy of the official repository to support local teamwork in Argentina.
Created a new data charging model known as "Pay a fixed amount once, then use the service for the rest of the day" for the charging software. Approximately eleven million subscribers use it daily in Argentina, Uruguay, and Paraguay.
Set up a lightweight virtualization scheme using Solaris Zones feature, a precursor to Docker, for quick cloning of development and testing environments. The time needed to set up a new environment was reduced from several hours down to one.
Incorporated a replication and backup scheme for our local build servers to sync with Finland's remote build server infrastructure. This was achieved by using Rsync, VPN, SOCKS tunnels, and scripts run as cron jobs.
Proposed and developed a proof-of-concept multilingual Android app for subscribers to access their account information from the online charging system through an intermediate REST web service.
Re-engineered and extended online voucher crediting capabilities to allow further flexibility while awarding bonuses on time-based criteria.
Traveled to Ireland and India to get on-the-job training with senior engineers working on the Telecom charging platform.

Technologies: RSync, Gradle, Apache Maven, Jenkins, Apache Tomcat, Apache, Sybase, REST, SOAP, Java, CORBA, Solaris, C++

Oracle Developer, Java Developer

2006 - 2008

CTI Mobile Operator (via Cohen Sistemas)

Developed several improvements to the main customer service representatives Oracle Forms screen, focusing on fetching the charging provider's real online balance.
Developed a Java CORBA client to interact with the online charging platform. The Java application was built into the Oracle 10g RDBMS and could be called through PL/SQL stored procedures for integration with the existing customer representative app.
Developed an alternative Java CORBA client interface implementation through a SOAP-based web service for Oracle Forms running in an Oracle Application Server to consume. The previous client was setup on the RDBMS engine.
Implemented a transparent load-balancing scheme built into the CORBA client interface. This was done to take advantage of the horizontal scaling strategy implemented by the online charging platform vendor. Incremented the overall TPS by 60%.

Technologies: CORBA, Java, PL/SQL, Oracle Forms, Oracle 10g, Oracle9i

Oracle Developer, Oracle Pro*C Developer

2004 - 2006

E.P.E.C. Energy Company of the Province of Cordoba (through Lempert y Asociados)

Migration of the existing home-brew commercial Oracle Forms, Reports, and Pro*C software from an old command-line version run in IBM mainframe servers into the new Oracle Application Server Java runtime running on newly acquired Solaris servers.
Set up the existing commercial CRM Oracle app to be run as a custom app from inside the Oracle E-business Suite UI.
Developed a new offline cash registering software using Oracle forms. It was used mainly in rural areas where the internet link was unreliable or fast enough to provide proper access to the online cash registering software.
Developed a custom action to feed the central CRM with the offline cash register software data through FTP.
Replaced an old Win32 app with a new central CRM integrated form that generated a flat-file from the commercial database of streets and routes where electricity meters were located and the order in which these routes should be read.
Automated the generation, partitioning, and provisioning of the electric meter reading schedules and route information. This data was then transferred into the available handhelds.
Adapted, compiled, and tested plain C and Oracle Pro*C back-end processing software running on old IBM servers to compile and run in the new Solaris environment.

Technologies: Bash Script, C++, Oracle E-Business Suite (EBS), Solaris, Oracle

Experience

Deviva Accounting Software

A Ruby on Rails web accounting software project using AngularJS.

Education

2000 - 2008

University Degree in Software Engineering

Universidad Tecnologica Nacional - Cordoba, Argentina

Certifications

JUNE 2024 - JUNE 2026

Pearson PTE Academic

Pearson

NOVEMBER 2023 - NOVEMBER 2026

Certified Kubernetes Application Developer (CKAD)

The Linux Foundation

OCTOBER 2021 - OCTOBER 2024