Lucian Văcăroiu, Developer in Bucharest, Romania
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Lucian Văcăroiu

Verified Expert  in Engineering

Javascript Developer

Bucharest, Romania
Toptal Member Since
June 19, 2017

Lucian has 17 years of professional experience as a full-stack developer and solution architect. He's built web apps optimized for large-scale production performance and worked extensively with PHP, JavaScript (including Node.js, Vue, and React), SQL, NoSQL database back ends, and many AWS technologies. His skill set includes advanced topics like serverless architecture and modern data-mapping design.



Preferred Environment

PhpStorm, MacOS, Docker

The most amazing...

...thing I've written was the OS for a restoration project for a Soviet-era CNC machine that was used to make locomotive axles.

Work Experience

Lead Developer and Software Architect

2019 - 2020
Motoreco Parts
  • Architected and developed a complete PHP and AWS based serverless solution to support the client's daily operations as an MM/year auto-parts retailer. All of the solution's "moving parts" (from the PHP-compute to the MySQL database backend) scale automatically to meet the client's online-retail traffic needs and warehousing/supplier batch-processing needs, with absolutely no system administration required.
  • Designed and developed a sophisticated WMS and fulfillment management system with a Vue.js interface and a GraphQL API back end (part of the solution mentioned above) based on client specifications but also leveraging my own UX experience to simplify existing workflows.
  • Developed an entire CI/CD pipeline with orchestration between multiple AWS services (including Lambda, API Gateway, Aurora, S3, Elasticache, and Elasticsearch), GitLab and Cypress-based automated integration tests.
Technologies: Serverless, Vue, Laravel, PHP

Software Architect

2019 - 2019
Undisclosed Client (via Toptal)
  • Designed the complete system architecture and AWS technology orchestration for large-scale CMS with HA and CI/CD requirement, based on AWS Lambda, AWS DynamoDB, AWS CodePipeline, React, and Node.js.
Technologies: Amazon Web Services (AWS), AWS CodePipeline, Amazon DynamoDB, AWS Lambda, React, Node.js

Senior Node.js Developer

2019 - 2019
Alteryx (via Toptal)
  • Identified and improved the architecture and performance pain points in the React code in one of the client's flagship products. The client is traded on the NYSE and the product I worked on is actively being used by customers, so details are still under strict NDA.
Technologies: React, Node.js

Lead Node.js/React Developer

2018 - 2019 (via Toptal)
  • Architected a complete end-to-end microservice-based scalable and high-availability frontend and backend solution based on AWS services and leveraging open source technologies like React and Node.js.
  • Developed an entire CI/CD pipeline consisting of a complex orchestration of multiple AWS services (including Lambda, API Gateway, DynamoDB, and Aurora) to build, test and deploy several serverless APIs and client apps.
  • Designed and developed several serverless GraphQL APIs with Node.js, leveraging multiple AWS services (including Cognito, Lambda, API Gateway, DynamoDB, and Aurora) to serve as a back-end for multiple client apps.
  • Designed and developed several responsive PWA client apps using a React/Redux/Sagas stack, leveraging AWS Cognito for user authentication and authorization, including authorization and access to the aforementioned GraphQL APIs.
Technologies: Amazon Web Services (AWS), DevOps, GraphQL, AWS CodePipeline, Amazon Aurora, Amazon DynamoDB, AWS Lambda, Serverless, React, Node.js

Lead React Developer

2017 - 2017 (via Toptal)
  • Developed a React/Redux/Sagas PWA solution to support the client's fine-art shipping-management business. Requirements included consuming a pre-existing JWT-authentication based REST API written in Python, as well as adapting an older UI design to the modern responsive and async requirements of a PWA.
  • Reversed-engineered legacy Python code to figure out endpoint architecture and interfaces for a legacy API with loosely maintained documentation.
Technologies: Python, Sagas, Redux, React

Lead React Developer

2017 - 2017
Moment Studios (via Toptal)
  • Developed a React/Redux/Sagas PWA solution to support the client's mobile app with Instagram-like functionality. Requirements included consuming a pre-existing JWT-authentication based REST API.
  • Built an independent PWA solution to act as a back-office/administration interface that the client's employees would use to moderate user content.
  • Got up to speed quickly, self-managed and kept the project on track with minimal project specifications.
Technologies: Firebase, Sagas, Redux, React

Freelance Consultant

2011 - 2017
Freelance Work
  • Refined back-end code for Green Horse Games` MVP, a browser-based racing game, on the heels of their round A.
  • Implemented 2Parale Affiliate Network's long-term DevOps and SysOps strategies as well as consulted on expanding their tech team and development efforts.
  • Architected and developed the first local/regional cashback platform.
  • Architected and developed a complete PWA solution based on a purely-mathematical model for the statistical analysis of the European secondhand auto market, the goal of which being to estimate a fair purchase price and life-time maintenance cost of any make and model vehicle purchase.
  • Architected and developed a multi-campaign tracking system for mobile-app user acquisition with Facebook ads and the Facebook Ads API for
  • Architected and developed a web-based A/B testing solution, for PPC and PPV ad campaigns, based on a mathematical model for statistical significance, for Affiliate Window Ltd.
Technologies: Amazon Web Services (AWS), PowerMTA, MySQL, PHP, Ruby on Rails (RoR), Ruby, DevOps, AWS CodePipeline, Amazon Aurora, Amazon DynamoDB, AWS Lambda, Serverless, React, Node.js


2009 - 2011
eRepublik Labs
  • Oversaw the overall staffing strategy as well as day to day technical operations, including managing the supporting technical and financial infrastructure necessary for a team of roughly 30 people.
  • Initiated and led the effort to architect and implement what were, at the time, bleeding-edge DevOps strategies (DevOps was a little known buzz-word back then).
  • Helped the company transition its flagship product, a browser-based MMO, into the modern age and support a fast-expanding user base, on the heels of their series A funding.
Technologies: IBM WebSphere, MySQL Clustering, DevOps, LAMP, Ruby on Rails (RoR), Ruby

Client Testimonial (via Toptal)

"I have had the pleasure of working closely with Lucian since February 2020. He is an excellent team member, software engineer, and collaborator. Lucian is one of the most well-rounded, talented software engineers I have worked with, and he effortlessly understands the full concept of any project he is on. He is confident in his decisions and communicates his solutions well but is also open to alternative solutions to accommodate the company and team. While on our team, he has been the sole developer on several crucial projects and always produces top-notch products. Lucian is not only an excellent developer but a welcoming, hilarious, and easy-going coworker. I would jump at the opportunity to work on a team with Lucian anytime."
— Kirby Birch, Product Manager, St. Jude Children's Research Hospital

Client Testimonial (via Toptal)

"Lucian worked diligently under a tight deadline to produce a detailed and solid proposed technical approach for a large-scale software project. He is someone that I will certainly want to work with again in the future."
— Toptal Delivery Manager

Client Testimonial (via Toptal)

"We can without a doubt say that with Lucian's know-how and deep understanding of front and back-end development, we could safely concentrate on the business end and trust that he managed the architecture and development. Never was there a time we felt that we had to double-check and he would always be pro-active in coming back with suggestions on how to solve a particular issue. We always considered him a full trusted member of our team. Another testament to his expertise was applying his experience to something that was new for both parties, developing serverless on AWS with all the moving parts that that entails."
— Niklas Nåsén, co-founder

Client Testimonial

"Lucian is a great CTO with a strong entrepreneurial streak. He is a straight talker that will tell you how things are and is not afraid of taking risks where needed. A great person to have on any team and it was a privilege to work with him."
— Alexis Bonte, CEO at eRepublik Labs Limited

Client Testimonial

"If your internet company is in trouble or you want to take it to the next level, you need a Lucian. His results-oriented mindset is completed by great tech skills and online sales experience. He is the type of person that can solve the biggest problems that your company has. And you will realize this after the first conversation with him."
— George Lemnaru, CEO of Green Horse Games


SQL, GraphQL, HTML, CSS, ECMAScript (ES6), ES7, SCSS, JavaScript, PHP, Gremlin, HTML5, CSS3, Solidity, Ruby, Python


Redux, Express.js, Laravel, Sails.js, Bootstrap, React Native, Ruby on Rails (RoR)


React, Node.js, jQuery, REST APIs, Vue, Flexbox


Git, Terraform, Webpack, Lando, PhpStorm, PowerMTA


REST, Continuous Integration (CI), DevOps


Docker, Amazon Web Services (AWS), AWS Lambda, Amazon EC2, Blockchain, MacOS, LAMP, IBM WebSphere, Firebase


MongoDB, MySQL, Amazon DynamoDB, NoSQL, Amazon Aurora, MySQL Clustering


Serverless, Data Architecture, Software Architecture, Sagas, Freelancing, Architecture, Software Design, AWS CodePipeline, Leadership

2003 - 2005

Completed Credits towards a Master's Degree in Business Adminstration

Hyperion University - Bucharest, Romania