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Hi, I’m Justin Reynolds. I’m a software engineer with 11+ years of experience building high-performance, scalable client-server and web applications on the .NET ecosystem. I specialize in C#, .NET, SQL Server, Redis, React, Angular, TypeScript, and Azure, delivering fintech and healthcare solutions from architecture through production deployment. I enjoy technical leadership and collaboration in Agile teams, mentoring colleagues, driving design reviews, and championing best practices, testing, and secure, reliable software delivery in fast-paced environments.…Hi, I’m Justin Reynolds. I’m a software engineer with 11+ years of experience building high-performance, scalable client-server and web applications on the .NET ecosystem. I specialize in C#, .NET, SQL Server, Redis, React, Angular, TypeScript, and Azure, delivering fintech and healthcare solutions from architecture through production deployment. I enjoy technical leadership and collaboration in Agile teams, mentoring colleagues, driving design reviews, and championing best practices, testing, and secure, reliable software delivery in fast-paced environments.

Justin Reynolds

Full Stack Developer, Web Developer, Programmer, +2

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Hi, I’m Justin Reynolds. I’m a software engineer with 11+ years of experience building high-performance, scalable client-server and web applications on the .NET ecosystem. I specialize in C#, .NET, SQL Server, Redis, React, Angular, TypeScript, and Azure, delivering fintech and healthcare solutions from architecture through production deployment. I enjoy technical leadership and collaboration in Agile teams, mentoring colleagues, driving design reviews, and championing best practices, testing, and secure, reliable software delivery in fast-paced environments.…Hi, I’m Justin Reynolds. I’m a software engineer with 11+ years of experience building high-performance, scalable client-server and web applications on the .NET ecosystem. I specialize in C#, .NET, SQL Server, Redis, React, Angular, TypeScript, and Azure, delivering fintech and healthcare solutions from architecture through production deployment. I enjoy technical leadership and collaboration in Agile teams, mentoring colleagues, driving design reviews, and championing best practices, testing, and secure, reliable software delivery in fast-paced environments.

Available to hire

Hi, I’m Justin Reynolds. I’m a software engineer with 11+ years of experience building high-performance, scalable client-server and web applications on the .NET ecosystem. I specialize in C#, .NET, SQL Server, Redis, React, Angular, TypeScript, and Azure, delivering fintech and healthcare solutions from architecture through production deployment.

I enjoy technical leadership and collaboration in Agile teams, mentoring colleagues, driving design reviews, and championing best practices, testing, and secure, reliable software delivery in fast-paced environments.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

English

Fluent

Work Experience

Senior .NET Engineer at Atomic FI

June 1, 2022 - Present

Led the development of a payroll connectivity and direct deposit switching platform, building .NET 7/8 microservices to connect 50+ employer integrations and external partners for payroll transactions, servicing banks and fintechs. Engineered income and employment verification APIs using C# scraping and external data integrations to automate lender workflows. Designed and deployed production-grade RESTful and GraphQL APIs with ASP.NET Core, implementing OAuth2, JWT authentication, SSO, MFA, API versioning, and Swagger/OpenAPI docs; provided real-time updates via SignalR. Built a reusable UI component library (TypeScript/Angular) and a multi-step account opening wizard (React/TypeScript). Modeled high-volume MS SQL Server schemas (2M+ records) with indexing to maintain sub-50ms queries; implemented data sync between Azure SQL and Cosmos DB for 1M+ documents daily with eventual consistency. Pioneered AI-powered document processing using OpenAI APIs and ML.NET to extract paystub/tax data

Senior C# Full Stack Developer at SeatGeek

August 1, 2020 - June 1, 2022

Engineered B2B APIs in C#/.NET Core, hosted on AWS EC2 with SQS/SNS and RDS PostgreSQL, enabling inventory synchronization and settlement processing for third-party ticket sellers. Implemented secure REST APIs with API Gateway, request throttling, JWT/IAM authentication, versioning, and Swagger/OpenAPI docs, plus CloudWatch monitoring. Integrated end-to-end payment processing with Stripe, PayPal, and Apple Pay using a robust .NET gateway abstraction, with idempotent transactions, PCI-DSS tokenization, fraud detection hooks, and automated reconciliation. Built a real-time operations ETL pipeline using C#, Apache Kafka, and ksqlDB for monitoring. Migrated 1.5M+ patient records to Salesforce via Data Loader and Talend, maintaining data integrity. Processed 500M+ records through Databricks/Spark ETL pipelines, enabling ML feature engineering for real-time recommendations. Developed order-processing using AWS Lambda, S3, Step Functions, Stripe, and DynamoDB Streams. Unified 90+ external API

Web Developer at Grid Dynamics

July 1, 2015 - August 1, 2020

Led HIPAA-compliant healthcare platform development with multi-tenant SaaS using C#/.NET 4.6, RBAC, PHI auditing, encryption; contributed to HITRUST certification. Built EHR integration layer handling HL7 FHIR, HL7 v2.x, CDA, with MassTransit for message transformation and bidirectional syncing with Epic, Cerner, and Allscripts. Developed patient portal using ASP.NET MVC/Web API, JavaScript, Bootstrap, jQuery, delivering secure messaging, appointment scheduling, lab results, and clinical decision support, improving patient engagement. Deployed Azure Functions for serverless workflows and automated reconciliation. Migrated monolith to cloud-native microservices on AKS with Docker and Azure Service Bus, improving deployment velocity and resilience. Championed TDD with xUnit, Moq, FluentAssertions across 120+ service classes. Collaborated in Agile/Scrum/Kanban. Implemented parameterized reporting with DevExpress and export to PDF/Excel.