Stepan Goremykin

NDA

An integration platform acting as a bridge between a new member portal and a legacy Oracle database maintained by a third-party vendor.

Tech stack:

• .NET 9, Minimal API, Mediator, Entity Framework Core
• Oracle Database
• xUnit, Testcontainers, Verify, Bogus, MockHttp
• Docker, Azure Container Registry, Azure App Service
• Azure Key Vault, Azure Application Insights
• Microsoft Entra ID, Azure DevOps, Azure Pipelines, Terraform, Terragrunt

The main challenge was non-technical — acting as the connecting link between two separate companies: one building the new member portal, the other maintaining the legacy system. The teams operated in very different contexts, which required constant three-way meetings and a lot of effort to understand what data the portal needed and where to find it in the old system.

Responsibilities:

• Simplified infrastructure by removing redundant services (e.g. Azure API Management)
• Replaced paid MediatR with Mediator, removed paid FluentAssertions
• Long requirement-gathering sessions with both teams and API implementation
• Established snapshot testing foundation using Testcontainers, Verify, and Bogus; used AI to achieve full test coverage
• Maintained project documentation
• Delivered the project on time as a solo developer

NDA

A management information system connecting suppliers and distributors in the automotive aftermarket. Both parties regularly upload large turnover reports, which the system uses to calculate and forecast bonuses.

Tech stack:

• .NET 9, Dapper, Mediator, TickerQ
• Angular 20, NgRx, Tailwind
• Azure SQL Database, Azure Blob Storage
• Azure Container Apps, Azure Front Door, Azure Key Vault, Azure Application Insights
• Terraform, GitHub, GitHub Actions

The client came with an existing codebase in poor condition — no CI/CD, security vulnerabilities, unlicensed and outdated dependencies, performance issues, and no documentation. The goal was to refactor the codebase, resolve security issues, set up infrastructure and CI/CD, replace problematic dependencies, fix existing bugs, and implement new features — all within tight deadlines. I led the project and was responsible for scope assessment. It was challenging, but we delivered on time and the client was satisfied.

Responsibilities:

• Scope assessment and project lead; team consisted of myself, a DevOps engineer, and a junior developer
• Requirements gathering, proposing solutions, and UI/UX decisions
• Technical and architectural decision-making
• Replaced paid EPPlus with SpreadCheetah and Sylvan.Data.Excel — reduced file processing time from tens of seconds to milliseconds
• Replaced paid MediatR with Mediator
• Replaced unmaintained RepoDB with Dapper, fixing many potential SQL injections in the process
• Upgraded .NET to version 9 and Angular to version 20
• Refactored the entire codebase
• Optimized database queries and moved a large amount of logic from stored procedures to application code
• Reduced web application bundle size — replaced large PNG assets with WebP/AVIF, cleaned up dependencies
• Set up the GitHub repository and CI/CD pipelines
• Made infrastructure decisions in Azure
• Integrated Application Insights and configured alerts
• Conducted demos for the client

Eys is accelerating the digital transformation in eye healthcare. This e-health platform uniquely connects healthcare professionals, streamlining collaboration with telemedicine, digital referrals, and high-quality clinical eye examinations.

Tech stack:

• .NET 8, .NET Framework 4.7.2 & 4.8, Service Fabric microservices, MassTransit, OpenIddict
• Cosmos DB, MS SQL, Entity Framework
• Angular 18, AngularJS, TypeScript
• Azure, Azure Service Bus, Azure Key Vault, Azure Blob Storage, Azure App Services, Azure Application Insights
• Docker, RabbitMQ, FFmpeg & FFprobe, Quartz.NET
• GitHub, GitHub Actions

Responsibilities:

• Implementing features entirely — from the backend to the frontend, often related to video/image processing
• Code review
• Bug investigation & fixing
• Profiling, optimization, and refactoring
• Migrated the codebase from Azure DevOps to GitHub, including CI/CD
• Migrated the majority of services from .NET Framework 4.7.2 to .NET 8
• Promoted and integrated message queues in critical places
• Promoted and integrated Cosmos DB partial updates
• Set up infrastructure for clusters in Azure multiple times
• Participated in all design and architecture discussions
• Made decisions regarding a smooth transition away from Service Fabric
• Replaced unsupported, vulnerable, and non-cross-platform dependencies with modern alternatives
• Responsible for the staging environment — deployments, migrations, analyzing logs
• No dedicated designers, QA, or detailed specifications — responsible for UI/UX decisions, self-testing, gathering requirements, and proposing solutions
• In the absence of a technical lead, also responsible for production deployments and responding to alerts
• Integrated AI for automatic detection of pathologies in eye examination images
• Integrated various ophthalmic cameras for automatic image capture into the platform

NDA

Cloud infrastructure and mobile application for a WiFi & Bluetooth smart thermostat for electric underfloor heating.

Tech stack:

• .NET 6, microservice architecture, MassTransit, gRPC
• PostgreSQL, Elasticsearch, Redis
• Xamarin Android & iOS
• Azure, Kubernetes, Docker, RabbitMQ
• Azure DevOps, Azure Pipelines

Responsibilities:

• Full implementation of features mostly in the Android application
• Code review
• Bug investigation & fixing
• Optimization and refactoring
• Collaborated with cross-functional teams to define, design, and ship new features in time
• Actively participated in Scrum ceremonies
• Updated and maintained CI/CD infrastructure, including the iOS build environment

NDA

Practice management software for therapists, psychologists, social workers, and counselors, with telehealth and managed billing. Top 1 solution in this domain.

Tech stack:

• .NET Framework 4.8, .NET Core 3.1 & 5, Event Sourcing, CQRS
• MongoDB, Redis
• React, Backbone.js
• AWS, MongoDB Atlas

Responsibilities:

• Implementing features (frontend & backend)
• Code review
• Bug investigation & fixing
• Optimization and refactoring

NDA

A product offering direct access to all payment rails, account types, and treasury management through a single API set.

Tech stack:

• .NET Core 3.1, Service Fabric microservices
• MS SQL, ADO.NET, Redis
• Angular, React 16
• Azure

Responsibilities:

• Led a small team to develop a completely new module from scratch
• Code review

Servgrow

An all-in-one field service management software for home and commercial service businesses — scheduling, dispatching, customer management, invoicing, and payments.

Tech stack:

• .NET Core 3.1
• MongoDB, Redis
• Docker, Kubernetes
• AWS, MongoDB Atlas
• React 16
• GitHub, GitHub Actions

Responsibilities:

• Developed complete new modules from scratch based on designs, often with minimal or high-level requirements
• Proactively gathered and clarified requirements to ensure quality delivery
• Code review
• Bug investigation & fixing
• Optimization and refactoring

This is the earlier version of the Eys product, under its original name and tech stack.

Tech stack:

• .NET Framework 4.7.2 & 4.8, Service Fabric microservices
• Cosmos DB, MS SQL, Entity Framework
• SignalR
• AngularJS
• Azure, Azure Blob Storage, Azure App Services
• FFmpeg & FFprobe
• Azure DevOps, Azure Pipelines

Responsibilities:

• Implementing features entirely — from the backend to the frontend, often related to video/image processing
• No dedicated designers or QA — responsible for UI/UX decisions and self-testing
• Code review
• Bug investigation & fixing

VoiceBox

A platform for creating email templates using a visual in-browser designer, importing dynamic contact lists, and sending bulk emails.

Tech stack:

• ASP.NET MVC 5, MSMQ, Windows Services
• MS SQL, Entity Framework
• Razor, Backbone.js, jQuery, Bootstrap
• AWS SES, AWS SQS
• Bitbucket

Responsibilities:

• Implementing features (frontend & backend)
• Heavy work with SQL and stored procedures
• Extending a visual in-browser HTML email builder built on GrapesJS
• Ensuring consistent email rendering across popular email clients (including Outlook...)