Senior Software Engineer and Technical Lead, Fintech

Nick Metzger

Senior Software Engineer

Houston, TX 346-***-**** *********@*******.*** linkedin.com/in/nicolas-m-34760a351 Summary

Senior Software Engineer and Technical Lead with 9+ years of experience delivering enterprise fintech and financial platforms. Led modernization of .NET microservices and payment systems, improving invoice and transaction processing latency by up to 30%, reducing security audit findings by 35%, and stabilizing high-volume workflows during peak traffic. Strong track record building secure, scalable APIs, optimizing SQL and caching strategies, and operating production systems in regulated environments (fintech, banking, insurance).

Education

Bachelor of Science Aug 2013 – May 2017

University of Texas at Austin

Professional Experience

AvidXchange Jan 2025 – Jan 2026

Senior Software Engineer, Technical Lead (Contract)

• Designed and evolved cloud-native microservices using .NET 8, ASP.NET Core Web APIs, Clean Architecture, and DDD concepts, defining service boundaries, API contracts, and asynchronous workflows for high-volume AP invoice processing.

• Remediated security audit findings across .NET 8 APIs and background services by tightening authorization paths, validating approval of workflow access, and securing secrets with Azure Key Vault, reducing repeat audit findings by 35%.

• Built and governed RESTful APIs through Azure API Management with versioning, throttling, and security policies, improving API security, service governance, and downstream consumer reliability.

• Reworked synchronous invoice submission flows into Azure Service Bus–backed queues and topics, offloading long-running validation and approval steps to background processors and reducing request timeouts during peak invoice submission windows.

• Owned and optimized SQL Server 2022 data access using advanced T-SQL, including stored procedures, query plan analysis, indexing strategies, and transaction scope tuning, reducing average invoice processing latency by 20% and improving concurrency handling.

• Implemented distributed caching with Azure Cache for Redis for reference and workflow state data, reducing repeated database reads and improving API response times by 30% under high concurrency.

• Integrated AP workflows with Microsoft Dynamics 365 CRM via REST APIs and asynchronous messaging, refactoring stateful processing and adjusting startup and retry behavior to ensure reliable synchronization in multi-zone Azure deployments.

• Deployed Dockerized .NET 8 services to AKS, tuning startup configuration, health probes, and autoscaling behavior to stabilize invoice-processing services and reduce deployment-related rollbacks.

• Investigated production performance and reliability issues using Application Insights (request tracing, dependency tracking) and Azure Monitor logs, identifying slow dependencies and inefficient queries contributing to elevated latency and error rates.

• Provided technical leadership through code reviews and architectural discussions, helping enforce engineering standards and guide team members working within regulated financial systems. Level Feb 2022 – Dec 2024

Senior Software Engineer

• Led the incremental modernization of a monolithic app, extracting payment and wallet functionality into ASP.NET Core 6 microservices to reduce release coupling and support faster feature iteration.

• Implemented backend microservices using RESTful APIs and asynchronous workflows using ASP.NET Core with Azure Functions and Azure Storage Queues, offloading long-running payment and notification logic from synchronous request paths to eliminate timeouts during traffic spikes.

• Built and evolved React 18 + TypeScript payment and wallet UIs while aligning frontend state, validation, and error handling with backend APIs, fixing mismatches that caused transaction failures.

• Designed PostgreSQL data models and SQL queries, tuning indexes and transaction scopes to support growing transaction volume while maintaining predictable behavior during concurrent operations.

• Used Redis to cache reference and configuration data (feature flags, limits, lookups) shared across payment flows, reducing repeated database reads and stabilizing response times during traffic spikes.

• Implemented authentication and authorization using OAuth 2.0 / OpenID Connect, JWT tokens, and Azure Active Directory, securing payment APIs and partner integrations following OWASP practices.

• Introduced Redis caching for reference and configuration data, (feature flags, limits, lookup values) shared across payment workflows, reducing repeated database reads and stabilizing API and UI responsiveness under high-concurrency usage.

• Integrated with external banking and payment providers via REST APIs and webhooks, implementing idempotency, retries, and reconciliation logic to handle real-world financial transaction behavior.

• Deployed on Azure App Service and Azure Functions, using Application Insights to trace requests and diagnose prod issues tied to payment latency, integration failures, and data inconsistencies.

• Wrote unit and integration tests using xUnit and Moq for backend services and Jest for frontend components, improving confidence during rapid interation and reducing regression.

• Leveraged AI-assisted development tools (GitHub Copilot) alongside static analysis and code reviews to accelerate feature development, reduce boilerplate, and improve consistency across codebases USAA May 2016 – Jan 2022

Senior Software Engineer III

• Contributed across 3+ enterprise insurance and financial systems supporting policy administration, claims processing, and internal tools, operating within regulatory, security, and availability constraints.

• Built and maintained ASP.NET MVC applications using Razor views and .NET 4.x, delivering enhancements and fixes for systems used by internal operations and customer service teams.

• Developed server-side business logic and UI workflows in ASP.NET MVC and Web Forms, improving usability and reducing manual processing effort in policy and claims operations.

• Worked on early UI modernization efforts, contributing to Blazor (early adoption) and WPF-based internal tools that replaced older Web Forms components in targeted areas.

• Implemented and optimized SQL Server (2012–2016) data access using T-SQL, stored procedures, and batch jobs, improving execution time of reporting and nightly processing tasks.

• Supported SOAP and REST integrations between internal systems, gradually introducing RESTful endpoints alongside legacy SOAP services to improve interoperability and reduce tight coupling.

• Participated in batch processing and scheduled jobs (Windows Services / SQL Agent jobs) supporting policy updates, billing calculations, and data synchronization across systems.

• Wrote and maintained unit and integration tests using MSTest and NUnit, increasing coverage for business-critical workflows and reducing regression during frequent maintenance releases.

• Supported production environments by investigating UI defects, backend exceptions, and data inconsistencies, contributing fixes that reduced repeat incidents and operational escalations.

• Worked within on-premises and private-cloud environments, following strict SDLC, change- management, and release-approval processes typical of large financial institutions.

• Gradually took ownership of larger features and application modules, becoming a reliable contributor across teams and mentoring newer engineers toward the later part of tenure.

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