Yeiner is available for hire
Hire YeinerYeiner Fernandez
Verified Expert in Engineering
Laravel Developer
Medellín - Antioquia, Colombia
Toptal member since June 11, 2014
Bio
Yeiner is a skilled full-stack developer and engineering manager with high standards and sound techniques. His main languages are PHP, Ruby, Python, and Go, but he can also work effectively with React and React Native codebases. Yeiner has very good communication skills — he can keep the team in sync and discuss items with non-technical stakeholders in the company.
Portfolio
Attention
Go, Python 3, Kubectl, Temporal, Datadog, TypeScript, AI Automation, Python...
CQL, LLC
Laravel, Vue, Shopify API, Node.js, Shopify, React
GlossGenius
Ruby on Rails (RoR), Sidekiq, PostgreSQL
Experience
- Laravel - 5 years
- Ruby on Rails (RoR) - 4 years
- Python 3 - 3 years
- PostgreSQL - 3 years
- Go - 2 years
- Shopify - 1 year
- Django - 1 year
- Swift - 1 year
Work Experience
Tech Lead | Software Engineer
2024 - PRESENT
Attention
- Built and operated an integrations infrastructure processing thousands of sales calls daily across dozens of enterprise platforms (Gong, Outreach, Salesforce, HubSpot, etc), maintaining high uptime despite heterogeneous third-party API reliability.
- Designed and shipped an agentic AI tech support system using Claude APIs and Linear MCP integration, with confidence-based execution thresholds and diagnostic playbooks that automated ticket triage and reduced escalations to Engineering.
- Reduced integration request turnaround by 80% (from around a week to 1–2 days) by redesigning the intake-to-delivery process and introducing automation across Zapier, N8N, and AWS Lambda workflows.
- Led the Tech Support and Onboarding function as the strategic owner, setting direction for tooling, processes, and customer-facing technical operations in a fast-moving AI startup environment.
Technologies: Go, Python 3, Kubectl, Temporal, Datadog, TypeScript, AI Automation, Python, Artificial Intelligence (AI), APIs, Automation, Zapier, Full-stack, Claude, ChatGPT, LangChain, Large Language Models (LLMs)
Senior Laravel/Vue Developer
2025 - 2026
CQL, LLC
- Architected a 3-tier multi-tenant SaaS platform (Super Admin → Organizations → Store Divisions) enabling a B2B2C model for a western wear retailer, with isolated tenant data unified across special orders, invoices, work orders, and credit memos.
- Designed and shipped unified payment infrastructure integrating Stripe ACH for bank transfers, Shopify credit card processing, and check payments for corporate invoice settlements, with automated reconciliation across all three rails.
- Implemented real-time inventory synchronization across Shopify API, POS, and external inventory management systems, executing a mid-project migration from Stocky to SKU Savvy with zero downtime to active retail operations.
- Built a special orders workflow with conditional automatic eCommerce triggering based on live stock availability via Shopify API, paired with manual POS entry paths — synced bidirectionally with live inventory calculations.
- Delivered an end-to-end embroidery work order tracking system, managing the production lifecycle from POS intake through completion tracking, integrated with order data and inventory state.
Technologies: Laravel, Vue, Shopify API, Node.js, Shopify, React
Senior Software Engineer
2023 - 2024
GlossGenius
- Developed the infrastructure of a new service for SMS marketing campaigns.
- Planned the escalation strategies to mitigate incidents related to external notifications.
- Led the full development lifecycle of several projects related to external notifications.
Technologies: Ruby on Rails (RoR), Sidekiq, PostgreSQL
Engineering Manager
2022 - 2023
EverlyWell
- Led the entire OKR around incident management. Developed the whole process, wrote the documentation, and planned the strategies around delivering the message to the team for further implementation of the new process.
- Launched several projects for new product offerings in the enterprise division, built on top of third-party integrations. The work involved building middleware REST APIs, usually Rails Engines.
- Worked with the other engineering managers on uncovering our challenges around the existing processes and KPIs, specifically on-call and cycle time.
Technologies: Ruby on Rails (RoR)
Engineering Manager
2019 - 2022
SkillShare
- Hired and coached a team of 15+ engineers from different countries. I was accountable for their career progression and successful onboarding process.
- Launched several projects focused on improving the organization's efficiency through DORA metrics like cycle time, deployment frequency, MTTR, etc.
- Participated in the strategic planning and direction of the engineering leadership team.
Technologies: Agile Software Development, PHP, Yii, TypeScript 3, Amazon Web Services (AWS), MySQL
Senior Software Engineer
2017 - 2019
Swipecast, Inc.
- Implemented features on the mobile app in React Native.
- Did a complete refactoring of the web application. Turned the app into a single-page app with React.
- Created a few important features in the Ruby on Rails back end.
- Did a migration (with my team) from CoffeeScript to ES6.
- Implemented Redux, Redux Forms, and Redux Saga in the web app.
Technologies: PostgreSQL, React Native, Redux, React, Ruby on Rails (RoR), Ruby, Mobile Development
Director of Engineering and Screener
2015 - 2017
Toptal
- Maintained constant communication with hundreds of clients in the day-to-day and kept in sync with the team.
- Matched Toptal clients with their perfect developer candidates.
- Maintained one-on-one relationships with sales and customer experience team members to handle issues as they arose.
Technologies: Ruby on Rails (RoR), Laravel, React
PHP Engineer
2015 - 2015
Butchershop
- Worked on building a Drupal module that integrates the app with an external service.
- Wrote some JavaScript code to manage the Drupal integration with an external service.
- Wrote integration tests with SimpleTest in the Drupal integration code I wrote.
Technologies: JavaScript, Drupal, PHP
Software Developer
2015 - 2015
SocialEngine
- Worked with Laravel on the back-end side to improve some features in the existing system.
- Worked with jQuery on the front-end side to add features around posts and comments.
- Used Less, Git, Composer, and GitHub. Had a very dedicated code review system.
Technologies: Underscore.js, Git, jQuery, JavaScript, PHP, Laravel
Senior Software Engineer
2015 - 2015
Huge INC
- Worked on a big Symfony codebase. Figured out a few system design issues on the features I was working on.
- Learned and worked with Solr and worked with an Agile team.
- Handled code reviews and gave feedback to my fellow developers.
- Maintained strong communication with the team to avoid work blockages.
Technologies: Symfony, PHP
Software Developer
2014 - 2015
Youdrone
- Worked on improving a legacy codebase. It was the vanilla PHP code that required a lot of improvements.
- Made PayPal integration improvements. Worked towards a launch plan.
- Made usability improvements so users were able to upload videos.
Technologies: CSS, JavaScript, jQuery, PHP, MySQL
Software Developer
2014 - 2015
CraftInc S.A.S
- Developed a full-featured REST API used by an iOS client.
- Implemented code coverage of the REST API and back end of the app.
- Learned about unit tests, mocking, stubs, and testing techniques in general.
- Implemented integration with the iOS app through Apple push notifications.
- Managed a database using MySQL as a foundational technology.
- Wrote Objective-C code maintaining a pre-existing iOS app.
- Implemented improvements in the PHP/Laravel back end, adding new features to the REST API.
Technologies: Swift, iOS, OS X, Objective-C, REST APIs, Bootstrap, JavaScript, Composer, Laravel, Mockery, PHPUnit, PHP, MySQL
Software Developer
2013 - 2014
SproutLoud Media Networks
- Handled web development under sandboxed Linux environments.
- Fixed bugs for SproutLoud's marketing application as part of an outstanding development team.
- Wrote unit tests for the existing and new code in the back and the front end.
- Worked in an Agile team and learned about a Scrum workflow.
- Learned Git extensively and read the full Pro Git book.
- Developed part (with a team) of several important modules currently in use by the app.
Technologies: PHPUnit, Linux, Vim Text Editor, Ext JS, Zend Framework, PostgreSQL, PHP
Web Developer
2012 - 2013
Educa City
- Engaged in web programming under LAMP. Managed Linux servers.
- Developed REST APIs, interchanging information between systems using a one-entry API system and connecting through REST clients.
- Developed using the Yii Framework and Twitter Bootstrap.
- Created back-end rich UIs using jQuery UI and clients connecting and parsing JSON from the API.
- Changed all the company's infrastructure from GoDaddy to AWS. Used Amazon EC2, Amazon S3, Elastic Load Balancing (ELB), Amazon Route 53, Amazon EBS, and other AWS services.
- Extended my Linux skills while working on mission-critical software in the dedicated servers.
- Created an SPA with Knockout.js for an internal mailing system.
Technologies: Amazon Web Services (AWS), Knockout (Knockout.js), jQuery, CentOS, HTML, Bootstrap, CSS, REST APIs, Zend Framework, Yii, PHP, MySQL
Web Developer
2011 - 2012
Starbox S.A.S
- Engaged in web programming under LAMP, Linux servers, and LAN Network Management.
- Created two websites (Pásala Disfrutando and Plan de Hoy) along with another developer.
- Used Pásala Disfrutando's core to build dynamic websites as part of the Star Experiences project, for example, Scare.
- Configured the structure of a dedicated server migrating from one to another provider (LAMP, SMTP, etc.).
- Worked extensively on Starbox's administration back end.
Technologies: jQuery, Ajax, HTML, CSS, Linux, CentOS, Yii, PHP, MySQL
Web Developer
2010 - 2011
Educa City
- Developed and optimized a service provided by the company (SaaS).
- Optimized the software and its cross-browser compatibility, as it was previously just compatible with Firefox.
- Developed some modules in PHP 5; initiated the migration to a jQuery modular system.
- Added features to a proprietary PHP framework using PHP 5.
Technologies: jQuery, Ajax, CSS, HTML, PHP, MySQL
Experience
GardenOS
https://gardenos.appGardenOS is an iOS app under development; its purpose is to serve serious plant collectors and propagators (rather than casual gardeners).
The app will be launching in Q2 2026. It has a mobile client and a Python/Django back end that stores subscriptions, the plant ID feature set, and the underlying APIs. The mobile app is native Swift.
The app will be launching in Q2 2026. It has a mobile client and a Python/Django back end that stores subscriptions, the plant ID feature set, and the underlying APIs. The mobile app is native Swift.
Hayeshi Martial Arts
https://hayeshi.coThis is a multi-tenant app built in Python/Django. Hayeshi Martial Arts Studio in Colombia is one of the tenants. The admin interface feeds the front end. There's also an interface for non-super admins (bookkeeping, schedules, etc), and for instructors.
Ilyong Martial Arts
This is a Shopify store and a back office for a martial arts equipment store in Colombia. I built the theme based on the Ride theme but customized it for Ilyong, and implemented a WhatsApp-only checkout process as a POC.
Swipecast
http://www.swipecast.comSwipecast existed several years before I joined the company, but one of the founders and I did a pretty interesting job in the landing page revamp using ES6 and React.
We developed numerous features in the SPA through React and styled components while also improving the mobile app in React Native. I kept continuous improvements in the Ruby on Rails API.
We developed numerous features in the SPA through React and styled components while also improving the mobile app in React Native. I kept continuous improvements in the Ruby on Rails API.
Education
2018 - 2022
Degree in Software Engineering
Politecnico Grancolombiano - Medellin, Colombia
Skills
Libraries/APIs
REST APIs, jQuery, React, React Redux, Underscore.js, Mailchimp API, Sidekiq, Vue, Shopify API, Node.js, Liquid
Tools
PhpStorm, Claude, ChatGPT, Git, MacVim, Vim Text Editor, Sublime Text, Zapier, ITerm, Composer, Skype, Kubectl
Languages
JavaScript, PHP, SQL, HTML, CSS, Ruby, Python, Swift, Objective-C, TypeScript 3, Python 3, Go, TypeScript
Frameworks
Laravel, PHPUnit, Redux, Ruby on Rails (RoR), Zend Framework, Bootstrap, Ext JS, Symfony, Yii, Knockout (Knockout.js), Mockery, React Native, Django
Paradigms
REST, Object-oriented Programming (OOP), Service-oriented Architecture (SOA), Automation, Mobile Development, Agile Software Development
Platforms
LAMP, Linux, Visual Studio Code (VS Code), Amazon Web Services (AWS), iOS, CentOS, OS X, Drupal, MacOS, Shopify
Storage
MySQL, PostgreSQL, Datadog
Other
AI Automation, Artificial Intelligence (AI), APIs, Full-stack, Large Language Models (LLMs), User Interface (UI), Vi, Ajax, Browsers, Software Engineering, NeoVim Text Editor, Temporal, LangChain
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