Denis
From Portugal (GMT+1)
9 years of commercial experience
Lemon.io stats
2
projects done1835
hours worked2
offers now 🔥Denis – Ruby on Rails, React, Node.js
Denis is a person with a wide range of experience in IT. Besides commercial experience with Ruby on Rails for the last 5 years, Denis also has practical experience with such demanded technologies as Docker, ElasticSearch, and others. Starting a career in the IT field as the Support Manager made Denis a perfect person to make qualitative and client-oriented products. Denis is an easygoing, kind, and responsible person. Working with him is a pleasure! So, who’s first?
Main technologies
Additional skills
Rewards and achievements
Ready to start
ASAPDirect hire
Potentially possibleExperience Highlights
Senior Backend Developer
User enrolment project. It provides wireless headsets for retail companies so that their teams can communicate. One issue is that, until now, they haven't had a way to assign which user is/was with a specific headset, and that's where this project appeared. It runs on a premise device (built by the company itself), which is basically a Linux machine that communicates with a server on the cloud for reporting purposes. So a basic React application was created where the user could enroll to a headset by typing their username, pin number, and a pairing code. After that, it was registered on a local database and also sent to the cloud.
- Created on-premise (back end and front end) application architecture;
- Created most of on-premise Nest.js application;
- Worked on some features on the front end using React;
- Wrote code with 70%+ test coverage.
Senior Backend Developer
It is an international home improvement company with over 2,000 stores, supported by a team of over 78,000 colleagues. Denis worked on the next version of the website's checkout.
Deni`s main area of responsibility was to create new microservices using AWS CDK for infrastructure and store data on DynamoDB. He also used Kafka for communication between services using events.
Main developer for the project
This project combines medical, behavioral and environmental factors in an insight generating app designed specifically to support Autistic children.
- Migrated infrastructure from AWS to GCP;
- Created many new features, including notifications using event drive architecture;
- Improved many aspects of code, including solving bugs and refactoring bad code;
- Integrated with the messaging platform.
Full-Stack Developer
Partbot is an automotive aftermarket dropshipping where users could sell their car parts available to e-commerce merchants, and control how their parts are sold online, and Partbot handles the logistics with its partners.
- Implemented report an error functionality;
- Implemented CSV data export;
- Implemented media section for products (image, videos and etc.)
- Integrated with Easyship;
- Integrated with TecAlliance e-commerce.
Full-Stack Developer
Transrefrut is a platform that connects football players to clubs or managers. You can share players' experiences, clubs, or managers' openings for players or managers to apply and offer players to be hired.
- Implemented GraphQL API;
- Engineered the Requirements;
- Refactored existing code by applying clean code principles;
- Created new features end to end (from the Rails Backend to the React Frontend);
- Created unit test for most of the Backend code;
- Created Paypal integration.
Full-Stack Ruby on Rails Developer
This was a project created with a partnership between the Federal University of Goiás and the Goiás Government. Students from public education can send their essays on the platform so a machine learning model can review their essays and return their scores from each category. The whole system is made of two parts: a Ruby on Rails application that interacts with the user, stores and sends the essays to another part of the system which uses Python. The second one contains the trained model and is basically a Python FastAPI system.
- Created the whole ruby on rails system from the ground up;
- Integrated both systems using REST API requests;
- Created dashboards for students, teachers, and other education professionals;
- Dockerized the application.
Full-Stack Ruby on Rails Developer
Olho na Bomba is a project that is created to oversee fuel prices in the state of Goiás in Brazil. It is the platform where the gas station workers insert all fuel prices as they change the value so that customers can see in real-time what those prices are. The price insertion process was law-enforced back then, but it has been revoked, and the whole process is under legal dispute right now.
- Led the team;
- Distributed tasks, monitored and reported the results;
- Created the project architecture;
- Created the registration, price insertion, and the API for mobile applications;
- Deployed the application on the government infrastructure.
Full-Stack Ruby on Rails Developer
A platform that connects teachers to students. A student can send essays, receive feedback from the teacher, or sign up for classes.
- Refactored Code by using clean code principles;
- Managed system migration from Heroku to AWS;
- Added new features to the platform;
- Created a course platform for essay writing boot camps;
- Mentored intern developers;
- Improved overall performance using code and database optimization;
- Provided Quality Assurance support.