Denis Mileyko

Senior Software Engineer

Poloniex•  January 2022 - November 2023

Skills: Java, Spring, React, TypeScript, Node.js, PostgreSQL, MySQL, AWS, CI/CD, Github, PHP, Docker, Kafka, Figma, CSS, SASS, LESS, J2EE, JUnit, Jest Responsibilities: - Built an approval system for deposits, withdrawals, and transfers based on threshold amounts and user privileges (Java, React, TypeScript). - Integrated Jira API and Zendesk API. - Build back-end and front-end for scheduled jobs (Java, Spring, React). - Rebuilt legacy PHP system using Java + Spring. Designed reusable hooks and components for common data processing practices, user flows, and state management (React). - Developed back-end endpoints for the central information access point of a cryptocurrency exchange with a daily trading volume of $50+ million, safeguarding privileged information and integrating sensitive data sources. - Maintained permission check system (TypeScript, Node.js). - Assisted with data migration tasks during new trading system implementation. - Performed code reviews, testing, and deployments (Github, AWS).

Senior Software Engineer

TowneBenefits•  September 2018 - December 2021

Skills: C# .NET, Angular, PHP, SQL, MySQL, JavaScript, AWS, OpenAPI, RESTful, Linq, Bitbucket, Jira, CI/CD, SAML, SOAP, CMS, HealthCare.gov API, Microsoft Dynamics API, Applied Epic API, Terraform Designed and developed a large-scale solution that supports the daily operation of more than 2000 agents using PHP + MySQL. Designed and implemented solutions using C#.NET, PHP, HTML, JavaScript, CSS, AJAX, Angular.js, Bootstrap, C# .NET, Entity Framework, LINQ, MVC 5, jQuery, and REST APIs. Designed and managed AWS infrastructure for a scalable solution using Amazon EC2, VPC, Auto Scaling, S3, EBS, RDS, DynamoDB, ElastiCache, Route 53, Elastic Load Balancing, IAM, SES Integrated application events with Amazon SQS, SNS, CloudWatch, and CloudTrail. Developed integration with Healthcare.gov using SAML, and SOAP to facilitate direct online enrollments in marketplace coverage. Created detailed API specs in OpenAPI 3.0/Swagger and implemented client/server in C# .NET and PHP. Worked with business and IT stakeholders to develop project scope, and test plan for assigned teams, and managed the requirements development process. Responsible for applying project management knowledge, skills, tools, and techniques to project deliverables, processes, and systems. Managed and updated project plan Atlassian Jira through project completion. Worked with business and IT stakeholders to develop a work breakdown structure for monitoring and controlling assigned work through deliverables completion. Led project meetings; identified, documented, and prioritized scope changes and facilitated the approval process; maintained and updated all project documents. Set and manage expectations with team members. Maintained issues, risks, and other required project logs & facilitates resolution of all outstanding items. Executed communication plans & regularly reported status to the program lead. Prepared and participated in quality review checkpoints and obtained/secured and archived necessary approvals. Assisted leadership with business development tasks and proposal creation/delivery. Set up code versioning and CI/CD through Bitbucket/AWS. Used other tools like SVN and GitHub. Developed RESTful services, APIs, and OAuth2 authentication. Gathered requirements and specifications from the client, produced software development plans, designed and developed systems, and created test cases and plans. Designed responsive and interactive web applications with AJAX and jQuery supporting mobile devices touch screen features and all browsers. Created reusable JavaScript libraries, .Net application frameworks, and Web Services.

Senior Software Engineer

IntellecTechs•  June 2011 - September 2018

Skills: C# .NET, MVC, MsSQL, PHP, C++, PostgreSQL, WordPress, Laravel, MySQL, Node.js, React, Angular Web design, test, and implement state-of-the-art secure web interfaces, systems, and applications using C# .NET + MVC + MSSQL, PHP + MySQL Gathered requirements and specifications from the client, produced software development plans, designed and developed systems, and created test cases and plans. Designed responsive and interactive web applications with AJAX and jQuery supporting mobile devices touch screen features and all browsers. Created reusable JavaScript libraries, .Net application frameworks, and Web Services. Developed media server using Node.js + Backbone.js Developed a WordPress-based website supporting an unlimited amount of individually customizable sub-sites with minimal workload on a database. Developed multiple shopping cart solutions using Zen-Cart. Developed automated Dash Boards and tools to support the use of business operations metrics. Develop web applications and implement new processes to enhance online communications.