Igor is available for hire
Hire IgorIgor Stajic
Verified Expert in Engineering
Software Developer
Location
Novi Sad, Vojvodina, Serbia
Toptal Member Since
July 1, 2019
Igor is an experienced freelancer with over nine years of experience working in the JavaScript/TypeScript language and has perfected his skills. Lately, he's been focusing on React, Node.js, and Express.js. Igor can build any project from the ground up and is known for writing well-designed, testable, and efficient code using best practices. Igor is a hardworking, responsible professional and can work by himself and in teams.
Portfolio
Pfizer
React, Front-end, TypeScript, Node.js, REST APIs, Git, Jira, Bitbucket, Jest...
Freelance
Node.js, React Native, React, Ember.js, JavaScript, GraphQL, MySQL, PostgreSQL...
Hartree Works LTD
React, Firebase, RSS Feeds, XML, Podcasting, Chrome Extensions, Node.js, HTML...
Experience
Availability
Part-time
Preferred Environment
MacOS, Visual Studio Code (VS Code)
The most amazing...
...project I've worked on is the digitization of site intelligence processes for Pfizer.
Work Experience
Senior React Developer
2020 - PRESENT
Pfizer
- Digitized the site intelligence and selection workflow by building a streamlined web-based application, replacing the previous manual Excel-based process.
- Architected and built a React application from scratch using MUI.
- Worked in a team with other Toptal developers. Used Jira for task management and sprint tracking.
Technologies: React, Front-end, TypeScript, Node.js, REST APIs, Git, Jira, Bitbucket, Jest, MUI (Material UI), HTML, ECMAScript (ES6), JSX, Code Review, Source Code Review, Web Development, REST, HTML5, CSS, JSON, Chrome Developer Tools, Responsive UI, Architecture
Full-stack JavaScript Developer
2016 - PRESENT
Freelance
- Contributed to many projects using React, Ember.js, and Node.js.
- Worked mostly with startups, in small teams, and involved in all of the project lifecycle phases.
- Architected and developed complex solutions using both NoSQL and SQL databases.
- Integrated and worked with many third-party API services like Stripe, Algolia, Intercom, Zendesk, FirstPromoter, social network APIs, and more.
- Used both the AWS and Google Cloud Platforms.
Technologies: Node.js, React Native, React, Ember.js, JavaScript, GraphQL, MySQL, PostgreSQL, Firebase, MongoDB, TypeScript, Google Cloud Platform (GCP), Amazon Web Services (AWS), Git, REST APIs, REST, Figma, Full-stack, Full-stack Development, HTML, ECMAScript (ES6), JSX, Web Development, Firebase Realtime Database, HTML5, CSS, JSON, Chrome Developer Tools, Responsive UI, Stripe API, SQL, Stripe, Electron, APIs, Architecture, Tailwind CSS
Full-stack JavaScript Engineer
2022 - 2022
Hartree Works LTD
- Built a Node.js API MVP for manipulating RSS feeds.
- Built a Chrome extension MVP for reading and manipulating Google Calendar data.
- Worked and communicated directly with the founder on defining the features and architecting solutions based on ideas.
Technologies: React, Firebase, RSS Feeds, XML, Podcasting, Chrome Extensions, Node.js, HTML, ECMAScript (ES6), JSX, Full-stack, Full-stack Development, Web Development, Firebase Realtime Database, REST, HTML5, CSS, JSON, Chrome Developer Tools, Responsive UI, APIs, Architecture, Tailwind CSS
Full-stack React/Node.js Developer
2021 - 2022
Talis Protocol
- Worked on new features and bug fixes on a React application's existing front end (Next.js).
- Migrated a Node.js API and GraphQL resolvers from using DynamoDB to MongoDB with Mongoose.
- Built migration scripts for transfers from different third-party API providers.
Technologies: React, Next.js, Node.js, TypeScript, JavaScript, Amazon Web Services (AWS), GraphQL, MongoDB, Mongoose, Full-stack, Full-stack Development, MUI (Material UI), HTML, ECMAScript (ES6), JSX, Web Development, REST, HTML5, CSS, JSON, Chrome Developer Tools, Responsive UI, APIs, Architecture
Senior Full-stack JavaScript Developer
2019 - 2020
Support.com
- Worked as part of the core development team on the main SaaS product.
- Designed and developed integrations with complementary third-party systems using OneTrust, HubSpot, and Twilio.
- Developed data migration scripts for different external systems, importing over 100k user records.
- Worked in a fully remote team, interfacing with QA, UX, product design, and DevOps teams.
- Performed design and code reviews, shared knowledge, and contributed to system architecture design decisions.
- Worked on implementing unit and functional testing.
Technologies: Redis, PostgreSQL, AngularJS, Express.js, Node.js, React, JavaScript, Front-end, User Interface (UI), Website Performance, API Integration, Angular, Twilio API, MUI (Material UI), HTML, ECMAScript (ES6), JSX, Code Review, Source Code Review, Web Development, REST, HTML5, CSS, JSON, Chrome Developer Tools, APIs, Architecture
CTO
2018 - 2020
Home2Market
- Worked on rewriting and redesigning a web SaaS platform called Home2Market.
- Architected and built the back end using Node.js, Restify, and Firebase.
- Implemented many SaaS platform-related features and worked on integrating multiple third-party APIs.
- Architected and built a web application using React and Node.js.
- Implemented a new design and many features needed for the SaaS platform that real estate agents used to manage and market their listings.
- Committed to all stages of the development for an enterprise-grade platform—from developing an MVP, reviewing the UI designs, technology choices, getting it ready to release, releasing the platform, and maintaining it.
- Hired and managed two external contractors for some short-term work, supervising their work and performing code reviews.
Technologies: Firebase, Node.js, React, JavaScript, User Interface (UI), Website Performance, GraphQL, API Integration, Amazon Web Services (AWS), REST APIs, MUI (Material UI), HTML, ECMAScript (ES6), JSX, Full-stack, Full-stack Development, Code Review, Source Code Review, Web Development, Firebase Realtime Database, REST, HTML5, CSS, JSON, Chrome Developer Tools, Responsive UI, Stripe API, SQL, Stripe, Architecture
Lead Developer
2014 - 2016
TMNS Serbia (now Devoteam)
- Built a SaaS product's front end, from the ground up, using Ember.js.
- Worked with other team members, provided guidance, and helped them out when they were stuck.
- Conducted code reviews and enforced coding standards and best practices.
- Introduced junior developers to the Ember.js framework.
- Worked with product owners on defining the roadmap and breaking down user stories.
- Converted an existing AngularJS application to Ember.js.
- Grew the team from two developers to two front-end team of 2-3 developers, and built the back-end team over a two-year period, interviewing and hiring people as we expanded. I was the development lead and managed both front-end teams at the end.
Technologies: Ember.js, JavaScript, HTML, ECMAScript (ES6), Full-stack, Full-stack Development, Code Review, Source Code Review, Web Development, REST, HTML5, CSS, Linux, JSON, Hiring, Architecture, Python
Experience
Home2Market
Home2Market is a SaaS platform used by real estate professionals in the US to help them manage and market their listings. I've contributed to building the platform from scratch, working directly with the founder.
iCouch
https://icouch.meiCouch is an application that offers secure video, scheduling, client, and document management.
uBegin
uBegin is an online platform that allows people to learn, engage, and celebrate the collective action for 2030 sustainable development goals. It unifies an online social environment with tools for project collaboration and matching resources to project needs.
Love Wall
A mobile app that allows users to leave digital love messages on different locations, send "locked" messages to other users and rate places as more or less romantic.
Skills
Languages
TypeScript, JavaScript, HTML5, ECMAScript (ES6), HTML, SQL, GraphQL, CSS, ES7, Sass, SCSS, Less, XML, Python
Frameworks
Next.js, Ember.js, Express.js, MUI (Material UI), React Native, Redux, Bootstrap, Jest, Tailwind CSS, AngularJS, Angular, React-Bootstrap, Electron
Libraries/APIs
React, Node.js, REST APIs, jQuery, Stripe, React Redux, Stripe API, Twilio API
Tools
JSX, Git, GitHub, NGINX, Chrome Developer Tools, Flow, Jira, Webpack, Docker Compose, GitLab, Bamboo, Trello, GitLab CI/CD, Bitbucket, Figma, Mongoose
Platforms
Firebase, Visual Studio Code (VS Code), Linux, Amazon Web Services (AWS), Google Cloud Platform (GCP), Docker, MacOS, Heroku
Storage
Firebase Realtime Database, PostgreSQL, MongoDB, MySQL, JSON, Redis, Elasticsearch, Cloud Firestore, Databases
Other
Front-end, Full-stack, Full-stack Development, Code Review, Source Code Review, APIs, Architecture, SaaS, Website Performance, API Integration, Responsive UI, Google Tag Manager, Software as a Service (SaaS), SOLID Principles, ParcelJS, Minimum Viable Product (MVP), User Interface (UI), Interviewing, Hiring, Computer Science, Software Engineering, Web Development, RSS Feeds, Podcasting, Chrome Extensions
Paradigms
REST, Scrum, Model View Controller (MVC), Functional Programming
Education
2009 - 2014
Bachelor's Degree in Electrical and Computer Engineering (with Honors)
University of Novi Sad, Faculty of Technical Sciences - Novi Sad, Serbia
Certifications
MAY 2016 - PRESENT
Professional Scrum Master I
Scrum.org