Andrei-Sorin is available for hire
Hire Andrei-SorinAndrei-Sorin Popovici
Verified Expert in Engineering
Back-end Developer
Oradea, Bihor County, Romania
Toptal member since September 14, 2022
Bio
Andrei is a full-stack engineer with 6 years of production experience using Ruby on Rails and JavaScript. He has shipped SaaS across proptech, delivery platforms, and sports tech. He was the primary engineer on the tournament scoring engine at the core of Golf Genius' platform. In side projects, he builds applied AI products end-to-end: RAG pipelines, multimodal embeddings, and vector search. A proven problem solver since high school: USACO Platinum and top 1% in Google Hash Code b2020.
Portfolio
RealPage
Ruby on Rails (RoR), React, Sidekiq, Redis, Code Review, B2B, Rake, RSpec...
Mrsool Inc.
Ruby on Rails (RoR), APIs, Payment APIs, Software Architecture, Full-stack...
Golf Genius Software
Ruby on Rails (RoR), CoffeeScript, Haml, Resque, RSpec, Bootstrap, Sass...
Experience
- Algorithms - 9 years
- Data Structures - 9 years
- Ruby - 6 years
- Ruby on Rails (RoR) - 6 years
- RSpec - 4 years
- React - 3 years
- REST APIs - 2 years
- JavaScript - 2 years
Work Experience
Ruby on Rails Engineer
2023 - PRESENT
RealPage
- Was on the Community Rewards team for 2.5+ years on the LOFT Loyalty program. Joined as it got off the ground and built it up to the platform APIs that other RealPage products now build on.
- Architected a unified, vendor-agnostic redemption framework (adapter registry, pluggable funding sources) replacing per-vendor reward flows.
- Opened the Loyalty service to the wider RealPage ecosystem via the Kong Enterprise Gateway. Designed the first governed product-to-product API.
- Built core features end-to-end: points transfer on move-out, on-time payment bonuses, and full-stack analytics dashboards (KPIs, charts, admin controls).
- Merged 161 PRs and reviewed 100+ as a primary reviewer on the Loyalty codebase.
- Upgraded the production Rails application from 5.2 to 7.1, implemented its Azure DevOps build and deploy pipeline, containerized the application, and set up a parallelized Selenium Grid test environment, all before joining the Community Rewards team.
Technologies: Ruby on Rails (RoR), React, Sidekiq, Redis, Code Review, B2B, Rake, RSpec, Agile, Kong, Redux, Cypress, APIs, REST, REST APIs, Back-end Development, Web Development, Full-stack Development, TypeScript, Apache Kafka, Back-end Architecture, Ruby on Rails
Senior Software Engineer
2023 - 2023
Mrsool Inc.
- Brought in to the Integrations team at Mrsool, one of the largest delivery platforms in the Middle East, to reduce order-failure rates to external integrators: failure rates fell from around 15% to around 3% in my first week.
- Led the integration with the largest third-party restaurant aggregator (menu sync, order submission, item snoozing, order-update communication) and completed its partner certification.
- Established the new integration structure: a dedicated layer and ETL pipeline for communication with partners and restaurant systems such as McDonald's, Foodics, and Deliverect.
- Contributed over a third of the test coverage in the new integrations repository.
Technologies: Ruby on Rails (RoR), APIs, Payment APIs, Software Architecture, Full-stack, REST, Docker, Architecture, Sidekiq, Redis, Code Review, RSpec, Back-end Development, Web Development, Back-end Architecture, Ruby on Rails
Software Engineer
2021 - 2023
Golf Genius Software
- Became the primary engineer for the tournament scoring engine, the platform's largest and most critical part, powering events for organizations such as the PGA and USGA with live scoring and millions of tournament configurations.
- Built an ES6 module that lets internal and external partners connect to the scoring system, cutting partner onboarding complexity.
- Designed and built a V2 handicap-calculation system using a step-pipeline architecture with a dedicated DSL that drives 12+ handicap formats.
- Shipped features across the platform: payout distribution, match penalties, bracket-tournament options, PDF report generation, handicapping methods, and leaderboard viewing options.
- Conducted interviews and trained new employees as part of the recruitment team.
Technologies: Ruby on Rails (RoR), CoffeeScript, Haml, Resque, RSpec, Bootstrap, Sass, Sharding, Data Structures, Algorithms, Ruby, HTML, JavaScript, REST APIs, RubyMine, Slack, Databases, Software Engineering, Code Review, Technical Hiring, Interviewing, React, B2B, Git, jQuery, API Integration, SQL, Back-end, PostgreSQL, Full-stack, APIs, REST, Software Architecture, SaaS, Architecture, Mentorship, Back-end Development, Web Development, Full-stack Development, Back-end Architecture, Ruby on Rails
Software Engineer
2022 - 2022
Zen Arbitrage
- Tracked and fixed various issues, regardless of whether they were caused by bugs or AWS/Heroku infrastructure.
- Created a new service that acts as a search engine that allows users to find reasonable offers on eBay easily. I worked on implementing filters and designs according to the specifications on Figma.
- Redesigned and improved one of Chrome's extensions by adding new functionalities.
- Added staging environments for all of our microservices.
- Implemented integrations with Amazon Selling Partner (SP) API and Recurly. Also, I had to fix issues caused by some endpoints still being in beta.
Technologies: Ruby on Rails (RoR), Ruby on Rails 5, jQuery, Microservices, Sinatra, Elasticsearch, Heroku, Redis, SCSS, CSS, HTML5, HTML, Amazon Web Services (AWS), Agile, AWS Elastic Beanstalk, Amazon Merchant API, Amazon Marketplace Web Service (MWS), API Integration, SQL, Back-end, PostgreSQL, REST APIs, Full-stack, APIs, Payment APIs, REST, DevOps, Haml, Web Development, Ruby on Rails
Coach
2019 - 2020
Wellcode
- Taught computer science fundamentals to high-school students or people looking to change their profession to programming.
- Prepared students for the National Olympiad in Informatics by helping them improve their algorithmic thinking and problem-solving skills.
- Helped people pass their technical or coding interview by teaching them how to approach problems and explain solutions to the interviewer.
Technologies: Algorithms, Data Structures, Interviewing, Technical Hiring, Mentorship
Project History
Application for Arbitraging Profitable Books
A web application based on microservices built with Ruby on Rails and Sinatra. This application allows a user to find profitable books on Amazon easily. I contributed primarily as a back-end developer though I also worked on some DevOps tasks. My main job was to convert the application from using Amazon's deprecated MWS API to the new and modern Selling Partner API. I fixed some issues related to Redis and ElasticSearch. I also helped the support team with questions regarding how some features should work based on the code.
Search Engine for eBay Offers
A SaaS application that allows users to easily search for offers that might be resold for a profit. We do this by offering them filtering options unavailable through eBay. I was a full-stack developer handling the Ruby on Rails back end and front end written with JavaScript, jQuery, SCSS, and the deployments.
Move Me - Renter Move Checklist
Move Me is a service adjacent to On-Site (RealPage's property management software). This service was designed to help future renters of the properties managed by On-Site. It provides the user with an easy-to-use interface where they can upload or check all the documents needed for a successful move.
As a Ruby on Rails developer, I upgraded the application from Rails 5.2 to Rails 7. This implied upgrading the Ruby version and all the gems to appropriate versions for this transition. I also set up a Docker image and deployment pipeline in Azure DevOps.
As a Ruby on Rails developer, I upgraded the application from Rails 5.2 to Rails 7. This implied upgrading the Ruby version and all the gems to appropriate versions for this transition. I also set up a Docker image and deployment pipeline in Azure DevOps.
studAI
An AI-powered study platform I designed and built solo as a side project to help me learn more efficiently.
Students upload their study materials and learn through an AI tutor chat grounded in those documents, AI-generated quizzes and flashcards, and spaced-repetition review (SM-2 and Leitner). I implemented a RAG pipeline: LLM-based PDF transcription via the Anthropic Batch API, markdown-aware chunking, Voyage AI embeddings stored in PostgreSQL with pgvector, and top-k semantic retrieval.
Students upload their study materials and learn through an AI tutor chat grounded in those documents, AI-generated quizzes and flashcards, and spaced-repetition review (SM-2 and Leitner). I implemented a RAG pipeline: LLM-based PDF transcription via the Anthropic Batch API, markdown-aware chunking, Voyage AI embeddings stored in PostgreSQL with pgvector, and top-k semantic retrieval.
Education
2017 - 2020
Bachelor's Degree in Mathematics and Computer Science
Babes-Bolyai University - Cluj-Napoca, Romania
Skills
Libraries/APIs
REST APIs, React, jQuery, Sidekiq, Resque, Amazon Marketplace Web Service (MWS), Amazon Merchant API
Tools
RSpec, Rake, Git, RubyMine, Jira, Slack, Recurly, GitHub, Kong
Languages
Haml, Ruby, CoffeeScript, JavaScript, HTML, CSS, Sass, SCSS, HTML5, JavaScript 6, SQL, Python, TypeScript
Frameworks
Ruby on Rails (RoR), Bootstrap, Sinatra, Ruby on Rails 5, Redux, Cypress
Paradigms
B2B, Agile, Microservices, REST, Back-end Architecture, Continuous Integration (CI), DevOps, Azure DevOps
Platforms
AWS Elastic Beanstalk, Ubuntu, Amazon Web Services (AWS), Heroku, Docker, Apache Kafka
Storage
Redis, PostgreSQL, Databases, Elasticsearch, MySQL
Other
Data Structures, Algorithms, Back-end, Full-stack, Web Development, Ruby on Rails, Mathematics, Code Review, Technical Hiring, Interviewing, Mentorship, API Integration, APIs, Software Architecture, Back-end Development, Full-stack Development, Sharding, Operating Systems, Software Engineering, Payment APIs, SaaS, Architecture, Software as a Service (SaaS), RAG Pipelines, Large Language Models (LLMs), Vector Databases
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