Egor is available for hire

Egor Polishko

Verified Expert in Engineering

Full-stack Developer

Budva, Budva Municipality, Montenegro

Toptal member since August 27, 2014

Expertise

Multithreading Back-end Developers Full-stack API Web Development Front-end Enterprise Development Data Science SaaS Artificial Intelligence Java Database

Bio

Egor has been passionate about computers since childhood and is now a seasoned full-stack developer with 18+ years of experience. He has proven himself by developing various complex, clever, and exciting solutions. Egor is also interested in providing architect solutions combining different technology stacks and approaches. Known for excellent communication skills and self-motivation, Egor thrives in complex projects while maintaining a passion for continuous learning.

Portfolio

Toptal Client

Full-stack, Angular, TypeScript, NestJS, AWS Lambda, PostgreSQL, Images...

Scuti

JSON Web Tokens (JWT), Microservices, Google Cloud Platform (GCP), Cloud Run...

Ionpath, Inc. (on behalf of 5AM Solutions, Inc.)

Java, Angular, SCSS, WebSockets, Rust, Finite-state Machines (FSM), C, C++...

Experience

Java - 18 years
PostgreSQL - 10 years
Node.js - 10 years
JavaScript - 10 years
Full-stack - 10 years
Angular - 8 years
React - 6 years
TypeScript - 6 years

Availability

Full-time

Preferred Environment

IntelliJ IDEA, Linux, Windows

The most amazing...

...things I've done were working with cutting-edge technology in the MIBIscope System and contributing to cancer research.

Work Experience

Full-stack Developer

2024 - 2024

Toptal Client

Designed and developed a comprehensive web application that met all client requirements, serving admins, franchise management, and shop staff with role-based access and authentication. Used Angular for the front end and NestJS for the back end.
Crafted an intuitive, desktop-focused UI with Angular, suitable for users with limited technical expertise. Implemented features like drag-and-drop image upload and side-by-side image comparisons to enhance user experience and TIFF processing.
Built a robust back end with NestJS, integrating PostgreSQL for data management. Handled user authentication and image processing workflows and integrated AWS Lambda for AI-driven image enhancement.
Integrated AWS services, including Lambda functions for AI/ML image processing and S3 for secure image storage. Ensured efficient processing and scalability within the cloud infrastructure.
Created dynamic dashboards for different user roles, providing order management and audit trails. Enhanced operational oversight for staff and management through real-time data visualization.
Established a secure image-handling pipeline supporting various formats and resolutions. Integrated AI processing to deliver enhanced images, facilitating customer approval, download processes, and POS integration.
Managed the entire development lifecycle independently, from requirements analysis to production. Demonstrated proficiency in full-stack development and project management skills.

Technologies: Full-stack, Angular, TypeScript, NestJS, AWS Lambda, PostgreSQL, Images, Front-end, Back-end, Amazon S3 (AWS S3), Cloud, Auth, Agile Product Delivery, Product-led Growth (PLG), API Architecture, TypeORM, Web Development, Minimum Viable Product (MVP), RESTFul APIs, Artificial Intelligence (AI), Software Architecture, Authentication, Data Pipelines, Architecture, Software Design, IT Security, Content Management Systems (CMS), Webhooks, Database Architecture, AWS Step Functions, Front-end Architecture

Senior Architect

2018 - 2024

Scuti

Developed and maintained a high-performance marketplace platform, Scuti, catering specifically to gamers. The platform offers a personalized shopping experience with curated products and rewards, enhancing the gaming experience.
Architected core back-end services using Node.js/NestJS/Knex, integrating Cloud SQL for secure and scalable database management and deploying applications on Google Cloud Run to ensure seamless and efficient operations.
Engineered secure and scalable APIs for handling transactions, ensuring data integrity, and protecting user information through advanced encryption and secure data transmission protocols.
Optimized the platform for performance and scalability, ensuring a smooth user experience by leveraging PostgreSQL for efficient data storage and retrieval and React for a responsive, user-friendly front end.
Implemented a rewards system allowing users to earn Scuti$ on every purchase, facilitating in-game purchases across multiple connected games.
Collaborated closely with cross-functional teams, including product managers, UI/UX designers, and QA engineers, to deliver features that enhanced the user experience, such as daily rewards, price guarantees, and secure purchase mechanisms.
Played a role in the overall architectural design, focusing on cloud-native solutions and scalable infrastructure to support the growing user base and complex feature set.

Technologies: JSON Web Tokens (JWT), Microservices, Google Cloud Platform (GCP), Cloud Run, Kubernetes, Google Cloud SQL, Node.js, NestJS, Knex.js, PostgreSQL, CockroachDB, Go, React, GraphQL, Google Cloud API, Rust, APIs, Payment Gateways, Payment Processing, Full-stack Development, Next.js, Amazon Web Services (AWS), Amazon S3 (AWS S3), Complex SQL Queries, SQL, Databases, Role-based Access Control (RBAC), CSS, Single-page Applications (SPAs), Azure, Azure Cosmos DB, Azure Event Hubs, Azure Kubernetes Service (AKS), Figma, Back-end Development, Architecture, Docker, Tailwind CSS, API Integration, Single Sign-on (SSO), API Design, Front-end Development, GitHub, HTML, OpenAI API, PrimeReact, Data Modeling, Auth, Auth0 API, M2M, Machine-to-Machine (M2M), JSON Web Key (JWK), JSON Web Key Set (JWKS), Agile Product Delivery, Customer Relationship Management (CRM), Product-led Growth (PLG), Generative Artificial Intelligence (GenAI), API Architecture, Web Development, Payment APIs, eCommerce, RESTFul APIs, Artificial Intelligence (AI), Software Architecture, Authentication, Data Pipelines, Software Design, IT Security, Content Management Systems (CMS), Responsive Design, Spring Boot, Webhooks, ETL, CI/CD Pipelines, Database Architecture, Redis, Front-end Architecture, Containerization, Apollo Server

Senior Full-Stack Developer

2017 - 2022

Ionpath, Inc. (on behalf of 5AM Solutions, Inc.)

Developed and integrated the MIBIscope System, an imaging platform that enables comprehensive phenotypic profiling and spatial analysis of the tissue microenvironment, focusing on instrumental control for an electron microscope.
Designed and implemented a robust finite-state machine (FSM) to manage and track the states of the electron microscope, ensuring precise control and synchronization during imaging operations.
Developed WebSocket-based real-time communication features, enabling efficient and reliable data exchange between the MIBIscope™ software and the electron microscope hardware, ensuring high throughput and minimal latency.
Implemented a comprehensive data management system that saved all measurement data and operational logs to a centralized database, ensuring traceability and enabling advanced data analysis.
Contributed to the high-resolution imaging capabilities of the MIBIscope, allowing researchers to visualize over 40 markers simultaneously with single-molecule sensitivity and confocal-level resolution.
Enhanced the system's throughput, enabling the imaging of up to 90 regions of interest (ROIs) per day, supporting large-scale clinical cohort studies.
Collaborated closely with cross-functional teams, including hardware engineers and biomedical researchers, to refine the imaging process and optimize the system for 24/7 operation.
Ensured that the software met rigorous performance and reliability standards, critical for high-sensitivity Secondary Ion Mass Spectrometry (SIMS) applications in cutting-edge cancer research and other biomedical fields.

Technologies: Java, Angular, SCSS, WebSockets, Rust, Finite-state Machines (FSM), C, C++, SQLite, Full-stack, RxJS, Python, Google Cloud Platform (GCP), Full-stack Development, Complex SQL Queries, SQL, Angular Material, Databases, CSS, Single-page Applications (SPAs), Front-end, HTML Canvas, Figma, Back-end Development, Architecture, API Integration, API Design, Front-end Development, GitHub, Jest, HTML, PrimeFaces, Auth0 API, JSON Web Key (JWK), Agile Product Delivery, Product-led Growth (PLG), Data Build Tool (dbt), API Architecture, Firebase, ECMAScript (ES6), Web Development, Real-time Data, RESTFul APIs, Software Architecture, Data Pipelines, Django, Software Design, SaaS, IT Security, Responsive Design, ETL, CI/CD Pipelines, Database Architecture, Redis, Front-end Architecture, Containerization

Senior Font-end and Back-end Developer

2015 - 2021

SS&C Primatics

Developed a responsive Angular-based dashboard for the Gen1 NPA and EVOLV EA Macroeconomic Sensitivity Model, providing users with an intuitive interface to interact with current expected credit loss (CECL) estimates and macroeconomic forecasts.
Implemented dynamic data visualization components using Angular and D3.js to display complex economic macroeconomic sensitivity model (EMSM) multipliers, SDQ forecasts, and historical data trends.
Created reusable Angular components for model asset class selection, forecast period inputs, and scenario comparisons, enhancing code maintainability and user experience.
Integrated the front end with RESTful APIs to fetch EMSM data, ensuring real-time updates and data consistency with the backend. Implemented client-side data caching and state management using NgRx to optimize performance and reduce server load.
Utilized iframes initially within the front-end app to isolate complex components independently; embedded CECL estimates and the dynamic D3.js visualization within the iframe to focus on performance and functionality without impacting the main app.
Transitioned iframes to Angular elements (web components) to enhance performance and improve communication between modules.
Designed and implemented a responsive layout using PrimeNG and Angular Material, ensuring a consistent look and feel across desktop and mobile devices.
Added robust error handling and data validation on the front end to improve user feedback and data integrity.
Developed a specialized WebSocket protocol tailored to the project's specific needs, with the front-end implementation in Angular and the back end in Java, including a custom Spring adapter to allow real-time display of long-running server processes.

Technologies: Java, AngularJS, Angular, WebSockets, Keycloak, D3.js, Spring, Hibernate, Spring ORM, RxJS, TypeScript, JavaScript, PrimeNG, Jasmine, Karma, REST APIs, Responsive UI, SCSS, CSS, Sass, HTML5, NgRx, Full-stack, Webpack, Google Cloud Platform (GCP), Material UI, APIs, Full-stack Development, Complex SQL Queries, SQL, Databases, Role-based Access Control (RBAC), Single-page Applications (SPAs), Front-end, HTML Canvas, Figma, Back-end Development, Architecture, API Integration, Single Sign-on (SSO), Front-end Development, GitHub, Jest, HTML, Iframes, Large-scale Projects, Microservices, PrimeFaces, Auth, Selenium, Data Build Tool (dbt), API Architecture, E2E Testing, ECMAScript (ES6), Web Development, RESTFul APIs, Software Architecture, Authentication, Data Pipelines, Software Design, SaaS, IT Security, Content Management Systems (CMS), Responsive Design, Spring Boot, Webhooks, ETL, Enterprise, Event-driven Architecture, Multithreading, Event-driven Design (EDD), Database Architecture, Bootstrap, Data Analytics, Redis, Front-end Architecture, Containerization

Senior Full-stack Developer | System Designer/Architect

2015 - 2017

Fivepane, LLC

Led the end-to-end design and architecture of the social network platform, ensuring a robust, scalable, and high-performance system capable of supporting millions of active users.
Defined the technology stack, data flow, and integration strategies.
Spearheaded the platform's development, utilizing Java for back-end services, PostgreSQL for database management, and Angular for the front-end interface.
Directed implementing critical features, including user profiles, messaging systems, and news feeds.
Designed and implemented a custom object-relational mapping (ORM) tool in Java tailored to the project's specific needs. This tool streamlined the integration with PostgreSQL.
Optimized PostgreSQL databases, reducing query response times through indexing strategies, query refactoring, and effective use of caching mechanisms.
Developed dynamic, responsive user interfaces using AngularJS, incorporating features such as real-time messaging and user profile management.

Technologies: Java, Facebook API, MongoDB, PostgreSQL, AngularJS, WebSockets, Google Login, Bing API, Full-stack, Amazon Web Services (AWS), Webpack, Google Cloud Platform (GCP), APIs, Full-stack Development, Complex SQL Queries, SQL, Databases, Role-based Access Control (RBAC), CSS, Single-page Applications (SPAs), Front-end, HTML Canvas, Back-end Development, Architecture, API Integration, Express.js, API Design, Front-end Development, GitHub, HTML, PrimeFaces, Data Modeling, Supabase, Auth, API Architecture, ECMAScript (ES6), Web Development, Minimum Viable Product (MVP), RESTFul APIs, Software Architecture, Software Design, IT Security, Content Management Systems (CMS), Responsive Design, Database Architecture, Bootstrap, Front-end Architecture

Senior Java Developer

2015 - 2017

SPINS

Designed RESTful API endpoints, including defining URI structures, request/response formats (JSON/XML), and selecting appropriate HTTP methods. Ensured APIs were intuitive, scalable, and met business requirements.
Architected and developed modular, reusable server-side Java components that encapsulated core business logic and facilitated seamless interaction between various systems and services, promoting microservices architecture.
Developed RESTful APIs using Spring Boot and JAX-RS, focusing on clean, maintainable code.
Implemented OAuth and API key authentication, securing API access and communication via HTTPS.
Designed data access layers with Hibernate/JPA, optimizing database queries for high-traffic applications.
Established error handling and logging for reliable, maintainable services with real-time monitoring.

Technologies: Java, REST APIs, Git, REST, Linux, MySQL, Application Architecture, RESTful Services, Spring, Docker, Jira, Jenkins, Agile Software Development, Database Design, OpenID Connect (OIDC), MongoDB, OAuth, Full-stack, Amazon Web Services (AWS), Google Cloud Platform (GCP), APIs, Complex SQL Queries, SQL, Databases, Back-end Development, API Design, GitHub, HTML, Data Modeling, API Architecture, RESTFul APIs, Software Architecture, Software Design, SaaS, IT Security, Spring Boot, Enterprise, Event-driven Architecture, Multithreading, Event-driven Design (EDD), Elasticsearch, Database Architecture

Senior Full-stack Developer

2016 - 2016

Pfizer Inc. (on behalf of 5AM Solutions, Inc.)

Developed the front end of the Pharmacogenomics QC portal, focusing on AngularJS to create a responsive, user-friendly interface for managing clinical trial samples and quality control data.
Designed and developed advanced search functionalities, allowing users to retrieve and filter large datasets by various criteria, including assay metrics and LIMS metadata.
Improved user experience by implementing sorting capabilities, intuitive navigation, and asynchronous search results, which significantly reduced data processing times and improved workflow efficiency.
Integrated support for Ion Torrent NGS data, enabling users to upload, manage, and review complex genomic data within the portal.
Developed and maintained back-end services in Java, ensuring seamless integration with the Oracle database. Implemented RESTful APIs to enable efficient data retrieval and processing.

Technologies: JavaScript, Java, AngularJS, Oracle, Full-stack, Google Cloud Platform (GCP), APIs, Full-stack Development, Complex SQL Queries, SQL, Databases, Single-page Applications (SPAs), Front-end, HTML Canvas, Back-end Development, GitHub, HTML, Minimum Viable Product (MVP), Software Design, SaaS, IT Security, Event-driven Architecture, Multithreading, Event-driven Design (EDD), Database Architecture, Data Analytics, Front-end Architecture

Software Developer

2013 - 2014

Entech Solutions

Developed a multi-tier Intranet application for crawlers. Implemented the crawler to look for financial documents on local company networks or the Internet, parse them, and save them to a database.
Integrated the application with an existing corporate service via SOAP.
Developed tools for infrastructure and statistics.
Handled testing and quality assurance.
Developed the database.

Technologies: Liferay, SOAP, Oracle, MySQL, Spring, Java, SQL, Databases, Multithreading, Database Architecture

Software Developer

2013 - 2014

Creative Mobile

Developed a web server application for a mobile game called Drag Racing that had over 100M users.
Used Cassandra to handle huge amounts of game data. Used distributed locks with ZooKeeper.
Planned and designed the game with clusters in mind, using 10 Tomcats and 5 Cassandra nodes behind Nginx as a proxy.
Performed server load testing to measure approximate application throughput.
Developed a client library for interacting with game servers.

Technologies: Gradle, Spring, Cassandra, Java, Software Design, Database Architecture

Software Developer

2012 - 2013

Ritm

Developed a J2EE-based platform for gathering telemetric data from a large variety of security and fuel consumption GSM devices (e.g. server software for a device that measures the axle load of a truck and transmits the data to the main server).
Developed a persistence layer with the JPA framework on top of a MySQL database to fulfill the needs of storing and filtering data from devices.
Developed a scheduling web application for motor park staff (e.g. day/night shift management and adjustments).
Created a REST module with some features of the bigger system exposed to mobile clients.
Developed a reporting subsystem with Excel/PDF generation.

Technologies: Apache POI, GlassFish, MySQL, Jakarta EE, Java, Multithreading, Database Architecture

Software Developer

2011 - 2012

Tender Pro

Developed a sophisticated business-to-business tender system aimed to fulfill almost any middle business needs. Built the whole system on the Spring Framework paradigm of Inversion of Control.
Participated in transporting the business model to the Activiti framework.
Developing persistence storage using JPA technology with Hibernate as the persistence provider. Implemented the possibility of using JDBC in performance critical applications.
Projected and developed an universal RPC system based on JSON to provide a simple and efficient way to allow heterogeneous client application usage.
Performed testing and quality assurance.

Technologies: GlassFish, Activiti BPM, JPA, PostgreSQL, Spring, Java, Multithreading, Database Architecture

Software Developer (part-time)

2010 - 2011

Ailove

Maintained and fixed bugs at a large variety of websites.
Handled server-side development for multiplayer online games («Playmates», MTS Red Quest 2 game, online auctions).
Enhanced site features with geolocation and the Foursquare API.
Developed a NoSQL persistence layer with MongoDB and the Morphia mapping library.
Configured application servers.
Tested and maintained legacy code.

Technologies: MongoDB, Memcached, PostgreSQL, MySQL, PHP, Ehcache, Terracotta, Netty, Apache Tomcat, Java, Database Architecture

Software Developer

2010 - 2011

Swiss Re (R.O.S. Factory)

Participated in the development of a «Costing Platform» (COP) all-in-one solution for re-insuring business to business activities. Aimed to accumulate state of art tools and services for actuaries and underwriters to thoroughly model and price a large variety of casualty risks.
Participated in knowledge gathering activities.
Performed Android-based media player development. Ported the FLAC (lossless audio) library from x86 to ARM architecture with JNI support for further usage.
Performed database development.
Developed internal workflow tools (e.g. time scheduling application for corporate usage).

Technologies: MySQL, Android, Java, Database Architecture

Software Developer

2009 - 2010

DarkOnline

Developed the Java server for a multi-user online game for a social network. Dealt with high load performance issues and optimized client-server protocol. Clustered Java using Terracotta technology.
Handled database design and Hibernate development.
Developed and maintained web applications for Tomcat. Wrote Java servlets for routine game needs: registration, ratings, etc.
Developed and implemented an AI subsystem for non-playing characters in the game.
Solved protocol optimization problems.
Dealt with concurrency issues.

Technologies: MySQL, Terracotta, SmartFoxServer, Hibernate, Apache Tomcat, Java, Database Architecture

Software Developer

2008 - 2009

BridgeQuest Labs

Developed a GUI (Swing) interface for database management utility.
Developed an intermediate layer between C++ native code and the Java model.
Developed and maintained a corporative website using .NET technology.
Tested the GUI with automated software.
Handled scripting and maintenance activity.

Technologies: .NET, Java

Software Developer

2006 - 2007

Legion Business Systems

Designed and developed a PHP engine for a corporate website.
Developed a Java-based client for classical a web shop.
Maintained a corporate database and managed content.
Developed a bar code printing application.
Supervised content quality.

Technologies: PHP, Microsoft SQL Server, .NET

Experience

Scuti | Marketplace Platform for Gamers

http://www.scutirewards.com/

A high-performance marketplace platform that offers a personalized shopping experience for gamers, with curated products and rewards, enhancing the gaming experience.

I was the senior architect on this project, playing a key role in the overall architectural design. I focused on cloud-native solutions and scalable infrastructure to support the growing user base and complex feature set.

I architected core back-end services using Node.js, NestJS, and Knex.js, integrating Cloud SQL for secure and scalable database management and deploying applications on Google Cloud Run to ensure seamless and efficient operations. I also engineered secure and scalable APIs to handle transactions, ensure data integrity, and protect user information through advanced encryption and secure data transmission protocols.

Additionally, I optimized the platform for performance and scalability. I leveraged PostgreSQL for efficient data storage and retrieval and React for a responsive, user-friendly front end, ensuring a smooth user experience. I also implemented a rewards system that allowed users to earn Scuti$ on every purchase, facilitating in-game purchases across various connected games.

Education

2003 - 2009

Master's Degree in Computer Engineering

National Research University of Information Technologies, Mechanics & Optics - Saint Petersburg, Russia

Skills

Libraries/APIs

Node.js, React, REST APIs, PrimeNG, Complex SQL Queries, PrimeReact, Auth, Auth0 API, jQuery, Apache POI, Mahout, Google API, Facebook API, JAX-RS, Bing API, D3.js, RxJS, NgRx, Google Cloud API, OpenAI API, Cloudways API

Tools

Apache Tomcat, IntelliJ IDEA, GitHub, Eclipse IDE, Gradle, Git, Terminal, Apache Maven, Auth0, Figma, Jira, Jenkins, Keycloak, Karma, Knex.js, Webpack, Azure Kubernetes Service (AKS), AWS Step Functions

Languages

Java, JavaScript, SQL-99, TypeScript, GraphQL, HTML, CSS, SCSS, HTML5, SQL, ECMAScript (ES6), C++, Rust, Python, PHP, Scala, Groovy, Sass, C, Go

Frameworks

AngularJS, Spring, Hibernate, Angular, NestJS, OAuth 2, Next.js, Angular Material, Tailwind CSS, Express.js, PrimeFaces, Spring Boot, Bootstrap, Play Framework, Material UI, Jest, Selenium, Django, JPA, Netty, .NET, Akka, Activiti BPM, Spring ORM, Jasmine, JSON Web Tokens (JWT)

Paradigms

Functional Programming, REST, Concurrent Programming, Object-oriented Programming (OOP), E2E Testing, Application Architecture, Role-based Access Control (RBAC), API Architecture, ETL, Event-driven Architecture, Event-driven Design (EDD), Agile Software Development, Socket Programming, Microservices, Database Design

Platforms

Jakarta EE, Android, Linux, Docker, Google Cloud Platform (GCP), Kubernetes, JEE, Windows, Amazon Web Services (AWS), Azure, Azure Event Hubs, AWS Lambda, Firebase, SmartFoxServer, Oracle, Cloud Run

Storage

MongoDB, MySQL, PostgreSQL, Google Cloud, Databases, Data Pipelines, Elasticsearch, Database Architecture, Redis, Cassandra, Amazon S3 (AWS S3), Microsoft SQL Server, Memcached, NoSQL, SQLite, Google Cloud SQL, CockroachDB, Azure Cosmos DB

Other

Back-end, Full-stack, Springbot, RESTful Services, WebSockets, Google Login, Responsive UI, APIs, Full-stack Development, Single-page Applications (SPAs), Front-end, HTML Canvas, Back-end Development, Architecture, API Integration, API Design, Front-end Development, Large-scale Projects, Web Development, Minimum Viable Product (MVP), Real-time Data, RESTFul APIs, Artificial Intelligence (AI), Software Architecture, Authentication, Software Design, SaaS, Content Management Systems (CMS), Responsive Design, Webhooks, CI/CD Pipelines, Enterprise, Multithreading, Data Analytics, Front-end Architecture, Containerization, Kinde, Internationalization, Payment Gateways, Payment Processing, Single Sign-on (SSO), Iframes, Data Modeling, Supabase, M2M, Machine-to-Machine (M2M), JSON Web Key (JWK), JSON Web Key Set (JWKS), Agile Product Delivery, Customer Relationship Management (CRM), Product-led Growth (PLG), Data Build Tool (dbt), TypeORM, Payment APIs, eCommerce, IT Security, Apollo Server, SOAP, Liferay, GlassFish, Ehcache, Terracotta, OpenID Connect (OIDC), OAuth, Finite-state Machines (FSM), Images, Cloud, Generative Artificial Intelligence (GenAI)

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