Valeriy is available for hire

Valeriy Efimenko

Verified Expert in Engineering

Software Developer

Tbilisi, Georgia

Toptal member since October 26, 2022

Expertise

Full-stack Development Web Development Full-stack Front-end UI Libraries Back-end Back-end Development Single-page Applications (SPA)CSS JavaScript SQL REST APIs HTML5 React TypeScript

Bio

Valeriy is a principal developer and architect with over 14 years of experience. He has spent more than seven years focused on professional web development. His broad experience in various fields, such as web development, management, sales, marketing, and eCommerce, gives him a unique perspective on how to solve problems. Passionate about his field, Val is constantly improving his skills and adopting cutting-edge technologies.

Portfolio

Intelligent University

JavaScript, TypeScript, PostgreSQL, Redis, Webpack, React, REST, Docker...

Independent Consultancy

JavaScript, TypeScript, React, Go, PostgreSQL, Redis, REST, Full-stack...

Hommz Technologies Ltd

React, Node.js, PostgreSQL, Full-stack, TypeScript, REST APIs...

Experience

PostgreSQL - 9 years JavaScript - 9 years Web Development - 9 years React - 7 years TypeScript - 6 years Node.js - 6 years Webpack - 5 years Go - 4 years

Availability

Full-time

Preferred Environment

Visual Studio Code (VS Code), Terminal, Git, MacOS, Linux, Full-stack

The most amazing...

...thing I've created is a service mesh to streamline the local development experience, resulting in better team productivity.

Work Experience

Chief Technology Officer

2022 - PRESENT

Intelligent University

Assembled, led, and mentored a remote team of four to seven developers.
Designed and developed a platform solution with a proven stack of technologies and sophisticated tools for developer experience.
Developed a proof-of-concept web application and launched it as a minimum viable product (MVP).

Technologies: JavaScript, TypeScript, PostgreSQL, Redis, Webpack, React, REST, Docker, Microservices, Agile, Web Development, Full-stack, Leadership, Architecture, Software Architecture, APIs, Airtable, REST APIs, Back-end, Back-end Development, CSS, Single-page Applications (SPA), Software Design, Scalable Architecture, Requirements Analysis, HTML, Front-end, React Router, Technical Leadership, HTML5, Tailwind CSS, CTO, Full-stack Development, Front-end Architecture, Mentorship & Coaching, Code Auditing, SQL, Three.js, NPM, GitHub, Authentication, WebSockets, Vite, Minimum Viable Product (MVP), Databases, Payment APIs, Artificial Intelligence (AI)

Consultant and Architect

2018 - PRESENT

Independent Consultancy

Contributed to many small React web apps. Provided tailored boilerplates and sophisticated component systems for most of them.
Worked on architecture for several medium-sized web apps. Planned and implemented best practice architectural solutions regarding scalability, maintainability, security, cost-efficiency, etc.
Led a few teams through a modernization process, including incremental adoption of React and TypeScript.
Created an MVP for a few projects. Assembled and educated teams to continue the development process.
Anticipated future offers and developed tools and solutions to be applied in projects.

Technologies: JavaScript, TypeScript, React, Go, PostgreSQL, Redis, REST, Full-stack, Architecture, Software Architecture, APIs, Next.js, Airtable, REST APIs, API Integration, Microservices, Back-end, Back-end Development, CSS, Single-page Applications (SPA), Software Design, Scalable Application, Scalable Architecture, Requirements Analysis, Streaming, Video Streaming, GraphQL, Amazon Web Services (AWS), Vue, HTML, Front-end, React Router, Redux, Jira, Technical Leadership, HTML5, Tailwind CSS, Storybook, Full-stack Development, Front-end Architecture, Mentorship & Coaching, Code Auditing, SQL, Three.js, Supabase, React Query, NPM, GitHub, Vercel, Authentication, WebSockets, OAuth, SDKs, SCSS, TypeORM, Vite, Minimum Viable Product (MVP), Databases, Artificial Intelligence (AI)

Senior Full-stack Developer

2022 - 2023

Hommz Technologies Ltd

Led an architectural upgrade that cut the project's launch times from 20 seconds to 5 seconds on high-end devices and from 60-90 seconds to 16-20 seconds on standard devices.
Reduced hot reload duration from an erratic 5-10 seconds to consistently under one second, saving developers 1.3 to 2.25 hours weekly. These improvements led to a cumulative saving of 52 to 90 hours monthly for a team of 10 developers.
Prepared the platform for future upgrades in the React ecosystem, migrating to the latest version of the packages, ensuring a smoother user experience and more efficient code execution.
Developed a custom calendar section on the platform that integrates with all internal systems where data is collected, enhancing the sales team's ability to make data-driven decisions.

Technologies: React, Node.js, PostgreSQL, Full-stack, TypeScript, REST APIs, Full-stack Development, Front-end Architecture, Code Auditing, SQL, React Query, Maps, NPM, GitHub, NestJS, Authentication, WebSockets, SCSS, TypeORM, Vite, Payment APIs

Team Lead and Architect

2021 - 2021

Praqticom

Led incremental modernization of a technology stack.
Established an onboarding process and assembled a team.
Developed a set of sophisticated scripts to automate tasks throughout the project and improve the developer experience.

Technologies: Go, JavaScript, Docker, React, PostgreSQL, Node.js, Redis, TypeScript, Webpack, Full-stack, Leadership, Architecture, Software Architecture, APIs, REST APIs, Microservices, Back-end, Back-end Development, CSS, Single-page Applications (SPA), Software Design, Scalable Architecture, Requirements Analysis, HTML, Front-end, React Router, Technical Leadership, HTML5, Tailwind CSS, Full-stack Development, Front-end Architecture, Mentorship & Coaching, Code Auditing, SQL, React Query, NPM, GitHub, SCSS, Vite, Databases

Founder and CEO

2019 - 2020

Tralents

Automated a screening stage of a recruitment process by eliminating the need to review a majority of candidates using a set of interactive tools.
Developed tailored business simulations and serious games for a number of clients.
Created a set of boilerplates to scaffold client-requested solutions in a matter of hours.

Technologies: JavaScript, Node.js, PostgreSQL, Redis, REST, Vue, Excel 365, Full-stack, Leadership, Architecture, Software Architecture, APIs, REST APIs, Microservices, Back-end, Back-end Development, CSS, Software Design, HTML, Front-end, React Router, HTML5, Full-stack Development, Front-end Architecture, Mentorship & Coaching, SQL, Three.js, NPM, GitHub, SCSS, Databases

Business Development Director

2017 - 2018

Brandquad

Led a business development team to grow from four corporate clients to more than ten in a year.
Managed a process of negotiating, onboarding, and developing custom solutions for the most important clients.
Developed three solutions adopted by a business and included in a services pool.

Technologies: Negotiation, Sales, Jira

Management Trainee

2015 - 2017

Unilever

Developed a dynamic analytical tool to generate and visualize reports on distribution coverage with Microsoft Excel.
Developed a sales fraud detection tool with Microsoft Excel.
Participated in creating a local market eCommerce department.
Led integration of a PIM SaaS solution with an internal master data management (MDM) system.
Participated in landing a global concept and localization for the launch of nine stock-keeping units (SKUs) for the brand Axe (Lynx).
Used social platform APIs to develop target lists for context advertisements that increased engagement rates up to three times.
Volunteered to organize an event for more than 600 students as a part of an employer brand strategy.
Prepared a massive dataset for distribution coverage potential for a big data project with 30 days deadline within three days.

Technologies: Sales, B2C Marketing, Team Leadership, Excel 365, Leadership

Intern

2015 - 2015

Unilever

Took a leading role in a sales team assessment project for three countries with over 1,500 employees.
Delivered three-month term project target results in two months.
Received a recommendation letter for a management trainee program first of all interns.

Technologies: Human Resources (HR), Excel 365

Freelancer

2011 - 2015

Self-employed

Learned web development on my own while studying at a university.
Participated in projects with higher skill requirements to develop proficiency.
Delivered results under high pressure and with vague requirements.
Developed and supported multiple client projects simultaneously.

Technologies: HTML, CSS3, APIs, CSS, Front-end

Experience

The HUB | Developer Experience and Automation

A custom service mesh to streamline the local development experience. These simple configurations and automatic service discovery allow building a microservice architecture with ease. The main features include the following:

• Predetermined sets of resources that can be launched with one command
• Graph-based module dependencies
• Every resource on request
• Release resources on code change
• Automatic recovery on a fatal failure
• Asynchronous execution
• Close to production environments to eliminate discrepancies

PostgreSQL Migration Scripts

A set of custom scripts to help with migrations without a hustle during the prototyping stage when building a microservice. It enables rapid development by applying migrations and seed data from scratch as a list of SQL files executed sequentially.

React Boilerplate

A custom monorepo boilerplate for rapid prototyping with webpack, React 18, TypeScript, ESLint, and Tailwind CSS. I also added custom production and development servers with server-side rendering (SSR).

Transactional SMTP Service

Created a custom transactional SMTP service for internal and client use. The following jobs were done while making it:

• SPF, DKIM, DMARC, and TLS protocols
• Multiple domains
• Message broker
• Email verification and DNS record resolver
• IP reputation improvements

Education

2010 - 2015

Specialist Degree (Equivalent to Master's Degree) in Project Management

Moscow City Pedagogical University - Moscow, Russia

Skills

Libraries/APIs

React, Node.js, REST APIs, React Router, Vue, React Query, Three.js

Tools

Webpack, Git, GitHub, Webpack 5, Jira, NPM

Languages

JavaScript, TypeScript, HTML, CSS, HTML5, SQL, Go, GraphQL, SCSS, CSS3, Bash Script

Frameworks

Tailwind CSS, Next.js, Material UI, Redux, NestJS

Paradigms

REST, Asynchronous Development, Scalable Application, Requirements Analysis, DevOps, Microservices, Agile, DevSecOps

Platforms

Docker, Linux, Amazon Web Services (AWS), Vercel

Storage

PostgreSQL, Redis, Databases

Other

Web Development, Full-stack, Architecture, APIs, Back-end, Back-end Development, Single-page Applications (SPA), Software Design, Scalable Architecture, Front-end, Full-stack Development, Front-end Development, UI Libraries, Deployment, Routing, Minimum Viable Product (MVP), Leadership, Software Architecture, API Integration, Technical Leadership, CTO, Front-end Architecture, Mentorship & Coaching, Code Auditing, Authentication, WebSockets, CI/CD Pipelines, Negotiation, Sales, B2C Marketing, Team Leadership, Human Resources (HR), Excel 365, ESLint, Monorepos, SMTP, Airtable, Streaming, Video Streaming, Storybook, Supabase, Maps, OAuth, SDKs, TypeORM, Vite, Payment APIs, Artificial Intelligence (AI)

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