Senior .NET Lead Architect

Senior .NET Lead Architect – Azure Performance Optimization (2-3 Month Initial Contract)
We build digital products that businesses and their customers can't live without. From initial design through proactive maintenance and all the engineering in between, we work alongside technology leaders to build digital products with staying power. No two projects share a starting point, but the goal is the same: Mainstays for customers. Growth engines for clients.
As a Senior .NET Lead Architect at Foxbox Digital, you'll lead the modernization and performance-scaling of a healthcare-focused Azure platform from 500 to 10,000 transactions per minute. This role blends hands-on technical leadership, deep Azure expertise, and direct client engagement. You'll diagnose system bottlenecks, architect scalable cloud solutions, and guide a small cross-functional team through optimization and validation.
This is a contract role for 2-3 months, ideal for a senior technologist who thrives on performance challenges, architectural depth, and collaborative leadership.
The role is fully remote and open to applicants across LATAM.
What Success Looks Like (First 2-3 Months)
You've established trust with client engineering and product stakeholders as the lead architect and technical authority.Performance and scalability testing is completed, with clear insight into system limits and opportunities.Azure infrastructure and .NET APIs are optimized for 10,000 TPM throughput, validated through measurable results.The Foxbox team executes confidently under your leadership, following clear technical direction and standards.The client sees tangible improvement in reliability, speed, and cost-efficiency — and confidence in Foxbox's architectural leadership.
Responsibilities
Serve as client-facing technical lead for an Azure performance optimization initiative.Lead architectural assessments, design reviews, and code optimizations across .NET and Azure services.Identify and resolve system bottlenecks across application, data, and infrastructure layers.Drive scalability improvements for Azure App Service, API Management, SQL Database, Redis Cache, and Cognitive Search.Implement and interpret results from Azure Load Testing, Application Insights, and Log Analytics.Collaborate directly with client stakeholders to define architectural priorities and communicate progress.Mentor and guide developers to implement efficient, maintainable, and scalable solutions.Document architectural decisions, performance findings, and scalability recommendations.
Requirements
Who You Are
10+ years in .NET architecture and development, with proven success leading large-scale performance and scalability efforts.Expert-level knowledge of Microsoft Azure Cloud, including architecture design, cost optimization, and performance tuning across PaaS and serverless components.Hands-on experience optimizing C#, ASP.NET Core, SQL, and distributed caching solutions.Deep experience with Azure App Service, API Management, SQL Database, Redis Cache, Cognitive Search, Front Door, and Application Insights.Strong background in load testing, telemetry, and performance diagnostics using Azure Monitor and Log Analytics.Experience leading and mentoring teams, managing priorities, and interfacing with clients at a senior technical level.Excellent communication and presentation skills; comfortable explaining trade-offs and recommendations to both engineers and executives.Fluent English required.If U.S.-based, must be eligible to work in the United States.
Engagement Details
Type: 3-month contract (part-time, ~10 hours/week or 25% allocation)Focus: Azure performance optimization & scalability (.NET ecosystem)Location: Remote (U.S. or LATAM)Reports To: Principal Architect, Healthcare & Life Sciences
Diversity and Inclusion
Foxbox Digital is an LGBT-certified company (Illinois and National LGBT Chambers of Commerce). We are committed to building diverse and inclusive teams that power the digital revolution. We provide equal employment opportunities for all, ensuring a work environment free of discrimination and harassment. All employment decisions are based on business needs, job requirements, and individual qualifications. Foxbox encourages applicants of all backgrounds, ages, and experiences.

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