Martins is available for hire
Hire MartinsMartins Kozlovskis
Verified Expert in Engineering
Software Developer
Location
Riga, Latvia
Toptal Member Since
April 24, 2017
Martins is a seasoned full-stack web developer and technical leader, specializing in JavaScript and frameworks such as Angular, React, and Node.js. He is adept at building responsive, mobile-first websites and excels in leadership, effective communication, and fostering collaborative team environments.
Portfolio
Coinrule
TypeScript, JavaScript, React, Material UI, Architecture, Front-end...
Boston Consulting Group
Bootstrap, Python, Node.js, React, Angular, Material UI, Python 3, TypeScript...
Freelance
React Native, Bootstrap, Express.js, Node.js, MongoDB, Flux, React, Angular...
Experience
Availability
Full-time
Preferred Environment
Git, WebStorm, MacOS, Ubuntu
The most amazing...
...project I've worked on is a real-estate evaluation platform that uses ads and open data to allow users to make better investment decisions.
Work Experience
Lead Front-end Developer
2023 - 2023
Coinrule
- Spearheaded front-end development, focusing on key technical decisions to craft intuitive, responsive user interfaces in a fast-paced, crypto startup (Y Combinator-backed) environment.
- Struck a strategic balance between rapid code delivery and high code quality.
- Guided front-end strategies to build a robust and forward-looking tech stack.
- Played a collaborative role in task refinement, optimizing for both user needs and technical efficiency.
- Mentored team members in best practices, fostering a culture that values quality and cohesive teamwork.
Technologies: TypeScript, JavaScript, React, Material UI, Architecture, Front-end, Front-end Architecture, Mobile, Figma, Third-party APIs, Communication, Testing, Agile, Automated Testing, CI/CD Pipelines, GitLab, GitLab CI/CD, UX Design, UI Design, Web Development, API Integration, APIs, Data Visualization, Mobile Development, Technical Leadership, Data Processing, Leadership, Asynchronous Programming, Web UI, Web UX, Storybook, Package Distribution, NPM, HTML5, REST APIs, Responsive Web Apps, Postman, Auth0, MUI CSS, Dashboards, Next.js, Software Architecture, JSON Web Tokens (JWT)
Freelance Web Developer
2019 - 2023
Boston Consulting Group
- Maintained, deployed, and created new features for web apps.
- Improved the speed, efficiency, and UX of the apps.
- Integrated security and authentication for the apps.
- Added PWA features like offline usage for more efficient client demos.
- Collaborated closely with data scientists who were developing the back-end systems.
- Developed and improved demos used for pitching new clients.
Technologies: Bootstrap, Python, Node.js, React, Angular, Material UI, Python 3, TypeScript, Front-end, Front-end Architecture, Documentation, Communication, Testing, Automated Testing, Styled-components, CI/CD Pipelines, UX Design, User Experience (UX), User Interface (UI), UI Design, Web Development, API Integration, APIs, GitHub, Data Visualization, Widgets, Third-party Integration, Mobile Development, Data Processing, Leadership, Asynchronous Programming, Web UI, Web UX, Storybook, Package Distribution, NPM, HTML5, D3.js, REST APIs, Responsive Web Apps, Postman, Auth0, MUI CSS, Dashboards, Reports, Software Architecture, Data, Highcharts, JSON Web Tokens (JWT)
Freelance Full-stack Web Developer
2016 - 2020
Freelance
- Handled full-stack web development projects for clients ranging from large consultancies to one-man startups.
- Developed a project for a client operating in the financial services industry in the Hague, the Netherlands. Mainly worked with Angular and Node.js. Followed Agile development practices and test/behavior-driven development guidelines.
- Built a web app for a martial arts instructor who needed an app for managing students, classes, expenses, and more; used React and Bootstrap 3 in the front-end and Node.js (Express) in the back-end.
- Implemented a small web-scraping tool that parses data for a local client.
- Worked on a React project that implemented an intranet-like system for individual companies; also implemented the same app on mobile with React Native.
Technologies: React Native, Bootstrap, Express.js, Node.js, MongoDB, Flux, React, Angular, JavaScript, TypeScript, Full-stack, Architecture, Full-stack Development, Front-end, Front-end Architecture, Mobile, Figma, Third-party APIs, Communication, Testing, Agile, Automated Testing, CI/CD Pipelines, UX Design, User Experience (UX), User Interface (UI), UI Design, Web Development, API Integration, APIs, GitHub, Data Visualization, Mobile Development, Technical Leadership, Data Processing, Leadership, Asynchronous Programming, Web UI, Web UX, NPM, REST APIs, Responsive Web Apps, Auth0 API, Postman, MUI CSS, Reports, Minimum Viable Product (MVP)
Freelance Front-end Developer
2017 - 2019
Aegon Netherlands
- Developed a project for a client operating in the financial services industry in the Hague, the Netherlands.
- Worked mainly with Angular and also implemented microservices using Amazon Lambda and worked on building a REST API with Apigee.
- Followed Agile and behavior-driven development techniques and achieved over 90% unit test coverage.
- Worked on-site with the team and later moved on to work remotely.
Technologies: Amazon Web Services (AWS), Bootstrap, Microservices, Angular, JavaScript, TypeScript, Front-end, Communication, Testing, Agile, CI/CD Pipelines, Finance, User Experience (UX), User Interface (UI), UI Design, Web Development, API Integration, APIs, GitHub, Mobile Development, Leadership, Asynchronous Programming, NPM, REST APIs, Responsive Web Apps, Postman
Front-end Developer
2016 - 2017
Intrum Justitia
- Built an internal system's front end using Angular 2 as the UI framework and Angular Material as the UI component framework.
- Developed a few other internal web projects using JavaScript and Handlebars.js for templating.
Technologies: Angular Material, Angular, JavaScript, TypeScript, Front-end, Communication, Testing, Web Development, Asynchronous Programming, REST APIs, Responsive Web Apps
Senior Developer
2015 - 2016
Accenture
- Worked on different onsite projects in Europe as a front-end developer.
- Developed SAPUI5 framework projects in Walldorf, Germany—implementing, improving, fixing, and testing UI controls used within the SAPUI5 framework.
- Developed SAPUI5 app projects in Walldorf, Germany—specifically creating web apps using the SAPUI5 framework and a lot of experimental technology.
- Used Agile methodologies for planning and actual work on SAPUI5 app.
- Developed new UI features for a CMS used by a Norwegian telecom.
Technologies: Test-driven Development (TDD), AngularJS, SAPUI5, CSS, HTML, JavaScript, Front-end, Documentation, Communication, Testing, Agile, Automated Testing, Web Development, GitHub, Asynchronous Programming, REST APIs, Responsive Web Apps, MySQL
Developer
2014 - 2015
Scandiweb
- Implemented eCommerce sites using the Magento platform.
- Crafted the responsive design and customized modules (both front-end and back-end) for an e-store for a fashion retailer.
- Implemented custom lottery ticket generators in JavaScript with an ability to draw random numbers in different combinations.
Technologies: Magento, PHP, HTML, CSS, JavaScript, Front-end, Communication, Testing, Web Development, Asynchronous Programming, REST APIs, Responsive Web Apps
Developer
2013 - 2014
Linedata
- Developed a hedge fund back-office system with C# and the .NET framework; also wrote some PL/SQL procedures.
- Worked with an international team consisting of members located in Riga, London, and Hong Kong.
Technologies: PL/SQL, .NET, C#, Communication, Testing, Trading, MySQL
Client Support Analyst
2012 - 2013
Linedata
- Supported clients using hedge fund software that the company was selling.
- Performed technical tasks mostly using SQL and non-technical tasks that involved communicating with clients via email and phone.
Technologies: Oracle, SQL, Communication, Trading
Experience
Hesti: Real Estate Evaluation App
https://hesti.lv/enUsers can use the app to evaluate real estate with two different options.
The first option is AI-driven. I collect real estate ads with a web scraper, parse the data, and use it to train a machine learning algorithm that can predict current prices.
The second option is to view the historical data of real transactions. I use a public API to collect data on real estate transactions that the users can browse.
The first option is AI-driven. I collect real estate ads with a web scraper, parse the data, and use it to train a machine learning algorithm that can predict current prices.
The second option is to view the historical data of real transactions. I use a public API to collect data on real estate transactions that the users can browse.
Yelo: Road Traffic Rule App for the 21st Century
https://yelo.lvThis is a mobile app (iOS, Android built with React Native) for learning road traffic rules in Latvia. In this project, I worked as the technical co-founder of a 3-person team. Besides being in charge of the technical aspects of the app, I collaborated closely with the designer and product owner to make decisions on how the app should be made.
Anti-corruption App
https://pretkorupciju.lv/en/dataA database with procurement data that the users can filter and analyze.
I gathered a team of developers and business analysts for a hackathon where we created a web app for collecting and showing data from a public procurement office. The tool aimed at making the data (which was stored in XML files in an unorganized manner) easy to overview and filter. The tool (Angular in the front end and Express.js in the back end) helps people to identify suspicious procurements that might involve corruption.
• https://github.com/Kozlo/stop-corruption-web-app
• https://github.com/Kozlo/stop-corruption-api
I gathered a team of developers and business analysts for a hackathon where we created a web app for collecting and showing data from a public procurement office. The tool aimed at making the data (which was stored in XML files in an unorganized manner) easy to overview and filter. The tool (Angular in the front end and Express.js in the back end) helps people to identify suspicious procurements that might involve corruption.
• https://github.com/Kozlo/stop-corruption-web-app
• https://github.com/Kozlo/stop-corruption-api
Used Car Price Evaluator App
https://autocena.lv/I used a web scraper (CasperJS) that gathers data from the site and stores it in a MongoDB database. The data can be visualized, edited, filtered, or deleted in an Angular 2 app. The data is used by a machine learning (neural networks) algorithm that learns to predict car prices.
Skills
Languages
ECMAScript (ES6), HTML, TypeScript, HTML5, CSS, JavaScript, Python, PHP, C#, Sass, Less, SQL, Octave, GraphQL, Python 3
Frameworks
Angular, Bootstrap, Next.js, MUI CSS, Material UI, Express.js, React Native, Angular Material, Flux, Redux, Jest, JSON Web Tokens (JWT), AngularJS, .NET
Libraries/APIs
Node.js, React, REST APIs, jQuery, Auth0 API, Highcharts, TensorFlow, D3.js
Tools
Git, NPM, GitHub, Jira, Mongoose, Postman, Auth0, SAPUI5, Bamboo, Webpack, Babel, CasperJS, WebStorm, Figma, GitLab, GitLab CI/CD
Paradigms
Responsive Web Design (RWD), Testing, Automated Testing, Mobile Development, Asynchronous Programming, Test-driven Development (TDD), Behavior-driven Development (BDD), Scrum, REST, Agile, Search Engine Optimization (SEO), UX Design, UI Design, Continuous Delivery (CD), Continuous Integration (CI), Microservices, Management, Web UI Design, Web UX Design, Data Science
Other
APIs, Mobile First, Front-end Development, Responsive Web Apps, Full-stack, Architecture, Full-stack Development, Front-end, Front-end Architecture, Communication, Web Development, API Integration, Technical Leadership, Storybook, Dashboards, Reports, Minimum Viable Product (MVP), Software Architecture, Web Scraping, Machine Learning, Finance, Data, Artificial Intelligence (AI), Documentation, Third-party APIs, Styled-components, CI/CD Pipelines, Trading, User Experience (UX), User Interface (UI), Data Visualization, Widgets, Third-party Integration, Data Scraping, Data Processing, Leadership, Web UI, Web UX, Package Distribution, GitFlow, Web App Security, Apps, Econometrics, Mathematics, Economics, Business Administration, Startups, Mobile Apps, Data Analytics, CTO, GDPR, OpenAI
Platforms
Amazon Web Services (AWS), Ubuntu, Heroku, MacOS, Mobile, Magento, Oracle, Windows, Docker
Storage
PostgreSQL, MongoDB, MySQL, PL/SQL
Education
2009 - 2012
Bachelor of Science Degree in Economics and Finance
Stockholm School of Economics in Riga - Riga, Latvia
Certifications
NOVEMBER 2015 - PRESENT
Machine Learning
Coursera
OCTOBER 2015 - PRESENT
Usable Security
Coursera
OCTOBER 2015 - PRESENT
Software Security
Coursera
Collaboration That Works
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