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Nicolas Milcoff
Verified Expert in Engineering
Mobile Developer
Córdoba, Cordoba, Argentina
Toptal member since May 21, 2017
Bio
Nico is a software engineer, former startup founder, open source maintainer, conference speaker, Microsoft MVP, and CTO. He is a team player with 10 years of experience building software and helping teams achieve their goals effectively. An expert with a positive attitude, Nico will be a great addition to any team.
Portfolio
Persefoni
Go, dbt Cloud, Databricks, Confluence, Jira, MySQL, Snowflake, SQL, Auth0...
Persefoni
React, Next.js, Agile, Scrum, TypeScript, Storybook, Go, Gorm, Apache Kafka...
Persefoni
Next.js, React, GraphQL, Apollo Server, Node.js, Storybook, Design Systems, Go...
Experience
- Technical Leadership - 7 years
- React - 6 years
- Git - 6 years
- TypeScript - 5 years
- GitHub Actions - 5 years
- Microservices Architecture - 4 years
- Go - 4 years
- React Native - 4 years
Work Experience
Platform Software Architect
2023 - PRESENT
Persefoni
- Headed the transition to micro front ends and package management.
- Built a temporal-based framework in Go for report generation of any kind.
- Spearheaded the revamp of the platform's data ingestion process.
- Oversaw the migration from Power BI to GoodData for platform analytics.
Technologies: Go, dbt Cloud, Databricks, Confluence, Jira, MySQL, Snowflake, SQL, Auth0, Next.js, Temporal Cloud, React, TypeScript, Node.js, Apache Kafka, GitHub, GitHub Actions, Squirrel, Crowdin, CSS, Docker, Vite, Yarn Workspaces, Postman, Datadog, JavaScript, Jest, Yarn, Microservices, English, Webpack, Webpack 5, Microfrontends, Design Systems, Continuous Deployment, Public Speaking, Microservices Architecture, Leadership, Full-stack, Amazon Web Services (AWS), AWS Lambda
Lead Software Engineer
2021 - 2023
Persefoni
- Architected the implementation of global design language using the Components library.
- Headed the adoption of GitHub Actions and trunk-based development for the main monorepo.
- Provided support, mentorship, and guidance to individual contributors.
Technologies: React, Next.js, Agile, Scrum, TypeScript, Storybook, Go, Gorm, Apache Kafka, Terraform, Microfrontends, Webpack 5, Webpack, GitHub, YAML, GitHub Actions, Yarn, Microservices, English, Jest, Datadog, Yarn Workspaces, Docker, Playwright, Crowdin, Temporal Cloud, Auth0, Confluence, Design Systems, Apollo Server, Continuous Deployment, CSS, Bitbucket, MySQL, Microservices Architecture, Leadership, Full-stack, Amazon Web Services (AWS), REST APIs, AWS Lambda
Software Engineer
2021 - 2021
Persefoni
- Accelerated developers' productivity by enhancing the development tools that they use.
- Built a Windows Forms UI framework that accelerated feature development.
- Reacrchitected the platform's GraphQL back and front end using Apollo.
Technologies: Next.js, React, GraphQL, Apollo Server, Node.js, Storybook, Design Systems, Go, Visual Studio Code (VS Code), TypeScript, Yarn, Microservices, English, Jest, Datadog, Yarn Workspaces, Docker, Playwright, Crowdin, Auth0, Confluence, GitHub Actions, Webpack, CSS, Bitbucket, MySQL, HTML, Amazon Web Services (AWS), MongoDB, REST APIs
Lead Mobile Engineer
2020 - 2021
Top Retail Company
- Headed the team that rebuilt the eCommerce mobile app from zero.
- Implemented Redux Toolkit in a single weekend to massively reduce tech debt.
- Implemented Apple Pay and the whole suite of checkout possibilities for the cross-platform mobile app.
Technologies: React Native, React, TypeScript, Apple Pay, iOS, Android, Salesforce, Bitbucket, YAML, Redux Toolkit, Yarn, English, Jest, GitHub Actions, Leadership, Mobile Apps, REST APIs
CTO
2019 - 2021
Xablu
- Oversaw and led multiple development teams in a remote-first setup.
- Reduced time to market drastically while improving developer productivity by rearchitecting mobile apps.
- Provided technical guidance to external customers and internal company projects.
- Created an open-source library to easily consume REST and GraphQL APIs in C#.
- Established the foundations for TDD and testing coverage, which have increased.
- Delivered 10+ technical talks at different meetups around the world.
Technologies: Mobile App Development, Team Leadership, Redux, TypeScript, Visual Studio Code (VS Code), Android, iOS, Git, C#, Xamarin.Forms, Xamarin, Android SDK, Visual Studio, Mobile Architecture, Java, Swift, Solidity, .NET Core, React Native, React, CSS, GraphQL, Microsoft Azure, Continuous Deployment, GIS, Agile, Scrum, English, Docker, GitHub Actions, Design Systems, Public Speaking, NuGet, Leadership, Mobile Apps, HTML, Full-stack, REST APIs
Mobile Development Consultant and Trainer
2018 - 2021
Xablu
- Facilitated on-site training on mobile application development to top enterprises in New York (US), Mechelen (Belgium), and Almelo (The Netherlands).
- Authored and delivered training on strategically choosing the architecture for mobile apps.
- Trained and coached app development teams from UPS, Philips, and KPN.
Technologies: Mobile App Development, Visual Studio Code (VS Code), Mobile Architecture, React Native, Git, Xamarin.Forms, Xamarin, Visual Studio, iOS, Android, Flutter, React, Redux, C#, SQL, Public Speaking, English, Design Systems, NuGet, Microsoft Azure, Leadership, Mobile Apps, HTML, Full-stack, REST APIs
Core Project Maintainer
2017 - 2021
MvvmCross
- Architected and built a mechanism that allowed sharing code while respecting platform idioms without compromise (ViewPresenters).
- Managed community contributions, external communications, and mentorship.
- Designed architecture solutions to push the framework forward in the community.
- Presented the framework in conferences and public speeches.
Technologies: Mobile App Development, Android, iOS, Git, C#, Xamarin.Forms, Xamarin, Android SDK, Visual Studio, MacOS, Universal Windows Platform (UWP), GitHub, NuGet, English, Leadership, Mobile Apps
CEO | Lead Mobile Engineer
2014 - 2019
DGENIX
- Led a team of 1x developers with different seniorities involved in resource planning, coordination of tasks, and full responsibility for deadlines and objectives.
- Developed offline sync and background processing services for enterprise-grade mobile apps.
- Architected and developed cross-platform consumer mobile apps for investment groups.
- Led the architecture of a framework for mobile app development, including a plugin system and abstraction for standard functionalities.
- Created binding libraries for Xamarin and contributed to several community-maintained libraries.
- Gave guidance and support to junior developers, making coding guidelines, slides, and exercises to help new developers get started.
- Contributed to the functional analysis and design of UI/UX for mobile apps as part of the software development process.
Technologies: Mobile App Development, Team Leadership, Visual Studio Code (VS Code), Android, iOS, Git, C#, Xamarin.Forms, Xamarin, Android SDK, Visual Studio, Mobile Architecture, Firebase, Azure, .NET, MvvmCross, SQLite, Microsoft Azure, .NET Core, Model View ViewModel (MVVM), ASP.NET MVC, English, Confluence, Design Systems, Public Speaking, NuGet, Leadership, Mobile Apps, Full-stack, REST APIs
Mobile Developer
2017 - 2018
Cortina Productions
- Built a native cross-platform app for Android and iOS used by thousands of students in the US.
- Built an offline sync engine that simultaneously downloaded several videos with optimized battery consumption.
- Created Swift and Java Bridge libraries to be used in Xamarin.
Technologies: Mobile App Development, Android, iOS, Git, C#, Xamarin, Visual Studio, Java, Swift, Subversion (SVN), English, Mobile Apps, REST APIs
Mobile Developer
2017 - 2017
TillPOS
- Built an offline data synchronization engine in C#.
- Created cross-platform native applications for iOS, Android, and UWP.
- Built a printer infrastructure with ESC/POS for the existing mobile app.
- Created a cross-platform navigation service that respects platform idioms.
Technologies: Mobile App Development, Android, iOS, Git, C#, Xamarin.Forms, Xamarin, Visual Studio, MVVM Light Toolkit, SQLite, Bitbucket, English, Mobile Apps, REST APIs
Mobile Developer
2014 - 2015
Clover Sistemas SRL
- Developed a Xamarin-based cross-platform mobile app for one of the biggest health insurance providers in Argentina.
- Led the initiative for creating an internal testing framework for testing mobile apps in Xamarin, which was adopted by the whole company.
- Achieved 80% testing coverage while creating a cross-platform mobile app following the TDD methodology.
- Improved the NPS for a B2C app by 25% after implementing a carefully planned code refactor.
Technologies: Mobile App Development, Android, iOS, Git, C#, Xamarin.Forms, Xamarin, Visual Studio, Couchbase, MvvmCross, GitHub, TFS, Agile, Test-driven Development (TDD), NuGet, Mobile Apps, REST APIs
IT Intern
2013 - 2014
Laboratorio STEM
- Helped the company increase sales by 30% by creating custom reports with detailed information that was otherwise ignored.
- Analyzed the company's main processes functionally and created onboarding documents for new hires.
- Contributed to the company's efficiency by providing training and support to end users.
- Conducted a workshop for introducing SQL to non-technical team members.
Technologies: C#, Visual Studio, Crystal Reports, .NET, SQL Server 2014
Project History
Open Source Library: BreachDetector
https://github.com/nmilcoff/BreachDetectorA mobile, cross-platform library based on Swift/Java components that allow mobile apps to detect root, emulation, debug mode, and other security concerns at runtime. This library is available for Xamarin developers.
Open Source Framework: MvvmCross
https://github.com/MvvmCross/MvvmCrossI am a maintainer of MvvmCross, the popular MVVM framework for Xamarin.
MvvmCross allows developers to build clean, pixel perfect, native UIs while sharing behavior and business logic in a single codebase across all the supported platforms, using the Model-View-ViewModel (MVVM) design pattern.
MvvmCross allows developers to build clean, pixel perfect, native UIs while sharing behavior and business logic in a single codebase across all the supported platforms, using the Model-View-ViewModel (MVVM) design pattern.
Open Source Library: EasyTipView
https://github.com/nmilcoff/EasyTipViewThis library is a C# port of an existing Swift library with the same name. It allows developers to easily place fully customizable tooltips in their app UIs. It is available for Xamarin.iOS developers.
Open Source Library: RootBeer (Xamarin)
https://github.com/nmilcoff/rootbeerA Xamarin binding library for RootBeer, the famous Android Java component that allows developers to detect device root conditions in runtime. It is distributed through NuGet and customized to be C#-friendly.
Open Source Library: IOSSecuritySuite (Xamarin)
https://github.com/nmilcoff/IOSSecuritySuiteA Xamarin binding library for the original IOSSecuritySuite library, an advanced and easy-to-use platform security and anti-tampering library written in pure Swift. This project contains all the annotations that make it C#-friendly.
SailConnect Mobile
https://sailconnect.com/SailConnect mobile app is written in Xamarin using the traditional approach. It is available on Android and iOS. The app allows users to attend events, chat, and prepare together before the race starts.
iDriveYourCar Drivers Mobile App
This native mobile app, developed with Xamarin and MvvmCross, is available on iOS and Android platforms. It is part of the iDriveYourCar business process and supports the drivers' workflows. The app allows drivers to manage their personal information, trips, and reviews. It also supports all driver actions during a trip, including calls/chats with passengers or support, adding expenses, and more.
Reveal Page Mobile
A native mobile app available for iOS and Android platforms. Developed with Xamarin and MvvmCross, it uses SQLite, Fody, and ReactEx. It is a comprehensive mobile social network that connects people following their interests and passions. Users can add other users to their relationships within the app and have conversations with them. They can also publish posts, create their sticker, and create albums of stickers.
AtlonXpense Mobile
http://www.atlonxpense.ch/A native mobile app for expense management developed with Xamarin and MvvmCross. Through this app, company workers can handle their expenses in a very effective and efficient way by taking full advantage of the multimedia capabilities that today's smartphones bring. The application is available for iOS and Android platforms.
Billing App
A native mobile app for iPad developed using Xamarin and MvvmCross. It allows the owner's clients to generate documents, offers, work orders, and invoices offline and sync them later in the office. Clients can also sign invoices and work orders within the app, which improves and streamlines workflow.
ClinicApp Mobile
A native mobile app developed with Xamarin technologies. It is available for the Android platform. This app lets users generate medical appointments directly from their phones and choose a particular doctor, date, and time. Users can also manage relatives and create appointments for them.
AtlonPManager
A native mobile app for work and project planning inside companies. Through this app, users can manage their tasks and assignments, as well as exchange information with their coworkers. The application is available for iOS and Android platforms.
Education
2009 - 2017
Engineer's Degree in Software Engineering
National Technological University - Rosario, Argentina
2014 - 2015
Exchange Study Program in Software Engineering
Esslingen University - Esslingen, Germany
Certifications
JUNE 2023 - PRESENT
Full Time Go Dev
FULLTIMEGODEV
JUNE 2023 - PRESENT
Go: The Complete Developer's Guide (Golang)
Udemy
AUGUST 2020 - PRESENT
The Complete React Native + Hooks Course
Udemy
MARCH 2018 - PRESENT
Microsoft MVP
Microsoft
JULY 2016 - JULY 2017
Xamarin Certified Mobile Developer
Xamarin University
DECEMBER 2015 - PRESENT
First Certificate in English
Cambridge English Language Assessment
Skills
Libraries/APIs
Node.js, Xamarin.Android, Xamarin.iOS, LINQ, SQLite.NET, React, REST APIs, MobX, Playwright
Tools
Visual Studio, SourceTree, Fody, Slack, TFS, Git, GitHub, Visual Studio App Center, Bitbucket, Yarn Workspaces, Google Workspace, Xcode, Redux Toolkit, Firebase Cloud Messaging (FCM), Android Studio, Azure Mobile, Jira, Postman, Trello, NuGet, Webpack 5, Webpack, Auth0, Crystal Reports, Subversion (SVN), NPM, C#.NET WinForms, GIS, Terraform, dbt Cloud, Confluence, Squirrel
Languages
TypeScript, C#, XML, XAML, HTML, Go, Swift, GraphQL, JavaScript, Snowflake, CSS, YAML, Solidity, Java, SQL, Smalltalk, Prolog, UML
Frameworks
Windows Presentation Foundation (WPF), Yarn, Android SDK, Xamarin.UITest, Newtonsoft JSON, .NET, React Native, Next.js, MVVM Light Toolkit, Redux, NestJS, Gorm, Jest, .NET Core, AngularJS, ASP.NET MVC, Flutter
Paradigms
Agile Software Development, Model View ViewModel (MVVM), REST, Agile, Mobile UI Design, Mobile UX Design, Mobile Design, Microservices Architecture, Continuous Deployment, Microservices, Unit Testing, Scrum, Microfrontends, Test-driven Development (TDD)
Platforms
iOS, Android, Universal Windows Platform (UWP), Xamarin, MvvmCross, Crowdin, Visual Studio Code (VS Code), MacOS, Temporal Cloud, Docker, Amazon Web Services (AWS), AWS Lambda, Azure, Firebase, Salesforce, Apache Kafka, Databricks
Storage
JSON, SQLite, MySQL, Datadog, Couchbase, IBM Db2, SQL Server 2014, MongoDB
Other
Async/Await, Mobile Architecture, Leadership, Mobile Apps, Mobile App Development, Open Source, Xamarin.Mac, Technical Leadership, Team Leadership, Xamarin.Forms, Async.js, Public Speaking, Design Systems, GitHub Actions, Full-stack, User Experience (UX), Axios, Documentation, Writing & Editing, Vite, Microsoft Azure, Apollo Server, Storybook, Apple Pay, English, Genetic Algorithms, Android Development, Algorithms, Integration Testing, HTTP, Enterprise Resource Planning (ERP)
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