Christian is available for hire
Hire ChristianChristian Diego De Martino
Verified Expert in Engineering
Senior Full-stack Developer
Buenos Aires, Argentina
Toptal member since January 26, 2013
Bio
Christian is a software engineer with over 20 years of experience developing applications for big corporations and startups, working on the front and back end using Java, Python, JavaScript, Node.js, and React. Christian has a strong command of English, can communicate exceptionally well both verbally and in writing, and has worked remotely for over a decade.
Portfolio
SalsaMobi
TypeScript, React, Node.js, PostgreSQL, GraphQL, AWS Lambda, Terraform...
Eleos Law LLP
React, Node.js, TypeScript, Amazon Web Services (AWS), PostgreSQL...
Draft Hero - Main
JavaScript, Next.js, TypeScript, Azure, GitHub, Tailwind UI...
Experience
- Node.js - 8 years
- React - 7 years
- Amazon Web Services (AWS) - 7 years
- TypeScript - 5 years
- Next.js - 3 years
- AWS Lambda - 3 years
- GraphQL - 3 years
- NestJS - 2 years
Availability
Part-time
Preferred Environment
Node.js, React, JavaScript, TypeScript, AWS CLI, NestJS, PostgreSQL, Python, Next.js, GraphQL
The most amazing...
...thing I've built as a back-end engineer is a social video network back end in Node.js using GraphQL, WebSockets, and video transcoding in eight weeks.
Work Experience
Full-stack Engineer
2021 - PRESENT
SalsaMobi
- Developed a platform that allows end users to link their credit or debit cards to the app and earn automatic cashback when they make qualifying purchases with participating merchants.
- Added new features, such as year-over-year sales reports, providing highly valuable insight, among other features.
- Deployed new features to production after each Spring cycle. Used AWS Lambdas as our main solution for the back end and GraphQL.
- Gained experience with Kubernetes as we started to use AWS Elastic Kubernetes Service. Took charge of deploying our apps into the cluster.
- Used Terraform as our infrastructure-as-code solution.
Technologies: TypeScript, React, Node.js, PostgreSQL, GraphQL, AWS Lambda, Terraform, Amazon EKS, Amazon Cognito User Pools, Amazon API Gateway, Amazon S3 (AWS S3), Amazon CloudWatch, Amazon Web Services (AWS), Full-stack, Serverless Architecture, Serverless, AWS CloudFormation, Lambda Functions, CSS, HTML, REST APIs, RESTful Services, Lambda Architecture, Back-end, Full-stack Development, Back-end Development, Front-end Development, APIs, Next.js, API Development, Express.js, MERN Stack, Databases, Cloud Services, SaaS, Architecture, API Integration, Tailwind CSS, React Query, Supabase, Front-end, Amazon DynamoDB, Web App Development, Web Development, AWS Amplify, Code Review, Test-driven Development (TDD), Vercel, Storybook, Figma, Redis, Kubernetes, ESLint, CI/CD Pipelines, API Design, API/Services Architecture, MongoDB, Microservices, Sentry, Jest, SQL, Prisma, Material UI, GitHub, Tailwind UI, Progressive Web Applications (PWAs)
Node.js/React Developer
2024 - 2024
Eleos Law LLP
- Integrated interfaces with Amelia AI and developed workflows that handle user interaction.
- Implemented chatbot capabilities to enable text-based user engagement within the app.
- Created database tables and back-end infrastructure to support AI-driven conversations and interactions.
Technologies: React, Node.js, TypeScript, Amazon Web Services (AWS), PostgreSQL, Artificial Intelligence (AI)
Next.js Developer
2024 - 2024
Draft Hero - Main
- Helped create a product from scratch that worked as a wallet for a fantasy football application. As a founding engineer, I designed the application architecture.
- Used Next.js because it was the perfect framework for this type of product, and I also used a document-based database because it's very flexible.
- Worked on a product that allows the user to use PayPal, Venmo, and credit cards to fund their wallet.
Technologies: JavaScript, Next.js, TypeScript, Azure, GitHub, Tailwind UI, Minimum Viable Product (MVP)
Next.js Developer
2024 - 2024
Draft Hero - Main
- Created an app front and back end from scratch using Next.js and Microsoft Azure.
- Defined the application architecture using Azure Functions and Azure Table Storage.
- Defined basic repo structure and CI practices using GitHub Actions to automate deployment.
Technologies: JavaScript, Next.js, TypeScript, Azure, SQL, GitHub, Minimum Viable Product (MVP)
React and Next.js Developer
2024 - 2024
LJA Engineering
- Fixed outstanding issues that users very much needed.
- Implemented a suggestion algorithm to help the party chief gather their team members faster and more efficiently.
- Updated many libraries that were out of date for a long time.
Technologies: React, Next.js, TypeScript, AWS Lambda, Amazon DynamoDB, AWS AppSync, Domain-driven Design (DDD), ESLint, CI/CD Pipelines, API/Services Architecture, MongoDB, Jest, SQL, GitHub, Tailwind UI, Minimum Viable Product (MVP)
Full-stack Engineer
2020 - 2021
DataArt
- Created new experiences for children, such as HTML5 Canvas with crayons and pencils of several colors for drawing and sharing.
- Built the interface with legacy code (in Angular) to keep the UX cohesive and smooth.
- Wrote several unit tests and integration tests with QA engineers.
Technologies: React, JavaScript, Node.js, CSS, HTML, REST APIs, RESTful Services, Front-end Development, APIs, API Development, Express.js, MERN Stack, Databases, Cloud Services, SaaS, API Integration, Supabase, Front-end, Web App Development, Web Development, AWS Amplify, Code Review, Test-driven Development (TDD), Storybook, Figma, ESLint, CI/CD Pipelines, API/Services Architecture, MongoDB, Sentry, Jest, SQL, GitHub, Progressive Web Applications (PWAs)
Software Architect
2020 - 2020
Genium
- Worked as a back-end architect and created an MVP for a social network focused on live video streaming and chat.
- Held demos with investors, who were amazed by the results.
- Supervised the front-end work for Android and iOS.
- Handled the app's challenges, like reducing the video bitrate according to the client's network capabilities.
Technologies: NestJS, TypeScript, Docker, Node.js, PostgreSQL, Amazon S3 (AWS S3), WebSockets, GraphQL, HTML, REST APIs, RESTful Services, Back-end, Back-end Development, APIs, API Development, Express.js, TypeORM, MERN Stack, Databases, Cloud Services, SaaS, Architecture, API Integration, CSS, Supabase, Amazon DynamoDB, Web App Development, Web Development, AWS Amplify, Code Review, Test-driven Development (TDD), Figma, ESLint, CI/CD Pipelines, API Design, API/Services Architecture, MongoDB, Sentry, Jest, SQL, GitHub, Minimum Viable Product (MVP), Leadership
Sofware Engineer
2017 - 2020
FineTune Learning
- Built a whole education platform around the AP and pre-AP exams for students.
- Led and implemented a new pre-AP program for students looking to improve their opportunities to get better scores.
- Used React with Redux as a state manager, as well as REST and GraphQL through Apollo to communicate with the back end.
- Implemented a few back-end user stories in Node.js, Express, and MySQL (Aurora).
- Added an experience with Docker and Docker Compose for orchestration.
- Managed and stored PDF documents using Amazon S3 buckets.
Technologies: Redux, React, JavaScript, Python, Amazon Web Services (AWS), Full-stack, CSS, HTML, REST APIs, RESTful Services, Back-end, Full-stack Development, Back-end Development, Front-end Development, APIs, API Development, Express.js, TypeORM, MERN Stack, Databases, Cloud Services, SaaS, Architecture, API Integration, Supabase, Front-end, Amazon DynamoDB, Web App Development, Web Development, AWS Amplify, Code Review, Test-driven Development (TDD), Storybook, Figma, ESLint, CI/CD Pipelines, API Design, API/Services Architecture, Sentry, Jest, SQL, GitHub, Progressive Web Applications (PWAs), Spring Boot, Leadership
iOS Developer
2014 - 2015
Deviget, LLC
- Coded a migration project from RubyMotion to Objective-C.
- Worked for several months on a social network similar to LinkedIn, but with audio and text messages coded in Swift.
Technologies: REST APIs, RESTful Services, MySQL, Databases, Front-end, Code Review, Test-driven Development (TDD), GitHub, Minimum Viable Product (MVP)
Project Manager, Scrum Master
2009 - 2011
Nextive, LLC
- Managed a number of remote developer teams that used Scrum Agile methodology.
- Developed games and productivity apps for iOS and Android mobile platforms.
- Collaborated with clients and game designers to implement a product backlog on all games that were developed.
- Maintained a product roadmap to provide customers with realistic expectations, including establishing concrete dates for deliverables and project milestones.
- Synthesized business requirements and turned them into user stories.
Technologies: Objective-C, MySQL, Test-driven Development (TDD), Minimum Viable Product (MVP), Leadership
Software Engineer
2007 - 2009
Sabre
- Headed the corporate travel business team, integrating Scrum Agile practices into daily operations.
- Assisted the team in generating estimations for each user story in the sprint and product backlog.
- Negotiated deliverables and priorities with stakeholders, working across marketing and sales.
- Tracked bugs, risks, and tasks using Scrum methodology.
Technologies: Java, REST APIs, Back-end, Back-end Development, APIs, API Development, Databases, SaaS, Code Review, Test-driven Development (TDD), SQL, GitHub
Software Engineer
2006 - 2007
Verizon
- Coordinated development tasks with other team members, including product design, coding, and unit testing.
- Implemented new features, simplifying the calculation of actual call costs of a phone call across multiple carriers.
- Ported a legacy C++ application with thousands of lines of code into Java.
Technologies: HTML, REST APIs, Back-end, Back-end Development, APIs, API Development, Databases, SaaS, Java, Code Review, Test-driven Development (TDD), SQL, GitHub
Semi Senior Java Developer
2005 - 2006
Banco Credicoop
- Processed re-engineering jobs using BPEL and web services.
- Built web services to function on top of legacy systems.
- Designed and implemented products based on analyst requests.
- Designed process choreography using the WS-BPEL tool.
Technologies: HTML, Back-end, Back-end Development, Front-end Development, APIs, API Development, Databases, SaaS, Web App Development, Code Review, Test-driven Development (TDD), GitHub
Java Developer
2003 - 2005
Primary Brokers
- Created an electronic trading system from scratch for banks and brokers, using the Java WebStart platform.
- Used Windows XP to implement Agile software methodology.
- Designed and coded applications from scratch, including performing integration and unit testing.
- Involved in peer programming, design reviews, and peer reviews.
Technologies: Java, HTML, Back-end, MySQL, Back-end Development, Front-end Development, APIs, API Development, Web App Development, Code Review, Test-driven Development (TDD)
Experience
Advertising Platform
An advertising platform that enables users to get automatic cash back at thousands of places when shopping, dining, or booking hotels. This service is accessible to end users via mobile for both Android and iOS and a web interface for merchants. Merchants can also create and monitor their marketing campaigns through the web app.
I fixed many platform issues and added several features and UX improvements.
I fixed many platform issues and added several features and UX improvements.
The College Board Pre-AP Program
https://pre-ap.collegeboard.org/Led the pre-AP program from design to production deployment. I contributed to the improvement and maintenance of a large—if not the largest—education platform for high school students in the US.
My work also included adding many unit tests to increment code coverage, using React with Redux and Apollo for GraphQL queries, and working on the back end with Python.
My work also included adding many unit tests to increment code coverage, using React with Redux and Apollo for GraphQL queries, and working on the back end with Python.
My Fantasy Wallet
https://myfantasywallet.com/As a founding engineer for a startup building a fantasy football app, I designed the application architecture and implemented features.
I used Next.js because it was the perfect framework for this type of product, and I used a document-based DB because of its flexibility. The product allows the user to fund their wallet using PayPal, Venmo, and credit cards.
The wallet allows users to send and request money, ensuring security when dealing with money transfers.
I used Next.js because it was the perfect framework for this type of product, and I used a document-based DB because of its flexibility. The product allows the user to fund their wallet using PayPal, Venmo, and credit cards.
The wallet allows users to send and request money, ensuring security when dealing with money transfers.
Education
2000 - 2005
Engineering Degree in Information Systems
Universidad Tecnologica Nacional - Buenos Aires, Argentina
Skills
Libraries/APIs
React, Node.js, REST APIs, API Development, AWS Amplify, React Query
Tools
Figma, Sentry, GitHub, CircleCI, AWS CloudFormation, Prisma, Terraform, Amazon EKS, Amazon CloudWatch, AWS AppSync
Languages
JavaScript, TypeScript, HTML, SQL, Java, CSS, Python, GraphQL
Frameworks
Redux, Next.js, Jest, Express.js, Tailwind CSS, Material UI, Flask, NestJS, Spring Boot
Paradigms
Test-driven Development (TDD), Serverless Architecture, Lambda Architecture, API/Services Architecture, Microservices
Storage
Amazon S3 (AWS S3), Databases, MySQL, PostgreSQL, Amazon DynamoDB, Redis, MongoDB, Amazon Aurora
Platforms
Docker, Amazon Web Services (AWS), Vercel, AWS Lambda, Kubernetes, Azure
Other
Full-stack, RESTful Services, Back-end, Full-stack Development, Back-end Development, Front-end Development, APIs, MERN Stack, Cloud Services, SaaS, API Integration, Supabase, Front-end, Web App Development, Web Development, Code Review, Storybook, ESLint, CI/CD Pipelines, API Design, Tailwind UI, Minimum Viable Product (MVP), Progressive Web Applications (PWAs), Serverless, Lambda Functions, TypeORM, Architecture, Convolutional Neural Networks (CNNs), Leadership, Amazon Cognito User Pools, Amazon API Gateway, WebSockets, Domain-driven Design (DDD), Artificial Intelligence (AI)
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