Joao Rafael Martins

Linkedin Github joaoraf@me.com

+55 41 998693157 | Curitiba, Brazil

Experienced and highly skilled software engineer with over 10 years of experience in web and ML/AI development. Strong expertise in back-end development, cryptocurrencies, NLP research, and predictive modeling. Demonstrated ability to design and implement scalable and efficient software solutions using a variety of technologies. Passionate about solving complex challenges and driving impactful results.

EXPERIENCE

Senior Backend Developer @ Xapo Bank / Remote / 2021 – Present

• Improved back-end performance through the optimization of database queries and the implementation of caching mechanisms, resulting in faster and more efficient transactions.
• Developed new features and modules for the platform using Python and Flask, resulting in increased efficiency and scalability.
• Implemented new 3rd party integrations (such as Circle and Lightspark) to improve the platform’s functionality and user experience.
• Managed the maintenance and iteration of REST APIs, as well as the infrastructure using Terraform and AWS/Azure, ensuring high availability and security.

Full stack / ML Developer @ Collective / Remote / 2020 – 2021

• Contributed to the development and maintenance of the company’s web platform using Django and Celery for the back-end, and React for the front-end, resulting in a seamless user experience.
• Led the development of a tax calculation system for S-Corps companies in the USA, greatly simplifying the tax filing process for clients and achieving high user satisfaction.
• Developed ML applications using GPT-3, and predictive systems for user forecasting and customer support optimization using automated FAQ, improving efficiency and accuracy in these processes.

Full stack Developer / ML engineer @ Xapo Wallet / Remote / 2018 – 2020

• Worked on the development of the company’s cryptocurrency trading systems, including the integration with major providers such as Coinbase, FTX, and Fireblocks, resulting in increased trading volume and revenue.
• Developed and maintained the pipeline of all virtual transaction analysis in real-time, ensuring the detection and prevention of fraudulent activities.
• Led the development of the entire AI pipeline, from ETL to real-time predictive models and model interpretability, resulting in more accurate and reliable predictions.

Full stack Developer / ML engineer @ Olist / Remote / 2017 – 2018

• Developed and maintained private and open-source software, as well as the deployment and monitoring of microservices, ensuring high availability and scalability.
• Developed predictive models for churn detection, document classification, and other data science projects, as well as natural language processing tasks, resulting in improved business insights and decision-making.
• Used technologies such as Heroku, AWS products, Python, Django, React, NPM, jQuery, Redis, PostgreSQL, Docker, Sci-kit learn, TensorFlow, Keras, and PyTorch, to create robust and efficient software solutions.

Full stack Developer @ SmartGreen / Brazil / 2015 – 2017

• Developed web systems using Python and the Django Framework, as well as PHP, resulting in scalable and reliable web platforms.
• Created high-performance and scalable software using NodeJS, Python, and Go, resulting in faster and more efficient processes.
• Maintained and optimized front-end components using technologies such as ES6, React, and jQuery, resulting in a modern and user-friendly interface.
• Used TDD methodology and wrote unit, integration, and acceptance tests, ensuring the quality and reliability of the codebase.
• Maintained CI and CD servers, and created native packages (deb and rpm), streamlining the deployment process.
• Used agile methodologies such as Scrum, to efficiently plan and manage development tasks.
• Developed data analysis for anomaly detection, resulting in the identification and resolution of potential issues.

Web Developer @ AutoGestor / Brazil / 2014 – 2015

• Developed a web platform using PHP with a custom framework, and front-end interfaces using Jade and Handlebars, resulting in a user-friendly and intuitive platform.
• Created a REST API and integrated with other platforms, such as Facebook, Mercado Libre, and OLX, greatly expanding the capabilities and functionality of the application.
• Performed database administration and maintenance, ensuring the security and integrity of the data.
• Used technologies such as PHP, MySQL, JavaScript, HTML, jQuery, CSS, and Bootstrap, to create high-quality web applications.

Full stack developer @ Freelancer | 2009 – 2014

• Developed and maintained web systems using PHP and the Laravel Framework, as well as front-end interfaces using jQuery and Bootstrap, resulting in functional and user-friendly web applications.
• Created custom CMS solutions and e-commerce platforms, meeting the specific requirements and needs of clients.
• Integrated with payment gateways and APIs from other platforms, expanding the capabilities and functionality of the applications.
• Performed database administration and maintenance, ensuring the integrity and security of the data.

EDUCATION

Bachelor’s Degree in Information Systems @ FESP / Brazil / 2014-2017

LANGUAGES

• English — Fluent
• Portuguese — Native
• French — Basic Level
• Spanish — Basic Level