Asp.Net Core .Net Developer

Frazien Zayfar

Senior .NET Developer • Solutions Architect

Jersey City, NJ 07302 201-***-**** ***************@*****.*** SUMMARY

Senior .NET Developer / Solutions Architect with 11+ years building secure, cloud-native platforms and APIs across healthcare, fintech, and logistics. Expert in C#, ASP.NET Core, Web API, microservices, and SQL Server; strong in Clean Architecture, DDD, CQRS, and event-driven design. Track record of modernizing legacy stacks, cutting latency and change-failure rates, and optimizing cloud spend while aligning with HIPAA and SOC 2.

HIGHLIGHTS

• Cut P95 API latency from 1.1s to 380ms via CQRS, caching, and targeted indexing.

• Drove MTTR down from 90+ minutes to <30 minutes with OpenTelemetry and SLO-based alerting.

• Lowered cloud costs through right-sizing, SQL tier tuning, and KEDA autoscaling. CORE SKILLS

Languages & frameworks: C#, .NET 6/7/8, ASP.NET Core (Web API, MVC, Razor, Blazor), Minimal APIs, LINQ, ADO.NET, EF Core, Dapper, gRPC, SignalR, OData, Swagger/OpenAPI, GraphQL (Hot Choco- late)

Architecture & patterns: Microservices, Clean Architecture, DDD, CQRS, event-driven design, REST, SOLID, async/parallel programming, resiliency (Polly), idempotency/outbox, sagas/compensation, API ver- sioning, API gateways (APIM/YARP)

Cloud & DevOps: Azure (App Service, AKS, Functions, Service Bus, Cosmos DB, Storage, APIM, Key Vault, App Insights), Docker, Kubernetes, Helm, Terraform/Bicep/ARM, GitHub Actions, Azure DevOps, trunk-based development, feature flags, blue/green & canary, KEDA, Renovate/Dependabot Data & messaging: SQL Server, PostgreSQL, MySQL, MongoDB, Cosmos DB, Redis, Kafka, RabbitMQ, Azure Service Bus, CDC, partitioning/sharding, projections/read models Security & compliance: OAuth2/OIDC, Azure AD/Entra ID, ASP.NET Identity, RBAC/ABAC, TLS/HSTS/CORS, OWASP ASVS/Top 10, audit trails, STRIDE, PII/PHI handling, HIPAA, SOC 2, ISO 27001 Quality & observability: TDD/BDD, xUnit/NUnit/MSTest, Moq/AutoFixture, SpecFlow, Playwright/Selenium, Pact, SonarQube, Roslyn analyzers, OpenTelemetry, Serilog/NLog/Seq, App Insights, Prometheus, Grafana, Datadog, Sentry/New Relic, k6/NBomber, dotTrace, PerfView Front-end: HTML5, CSS3, JavaScript/TypeScript, React, Angular, Blazor, Tailwind, Bootstrap, Material UI, Vite/Webpack, jQuery

Tooling: Visual Studio, VS Code, Rider, SSMS, DBeaver, Postman, Fiddler, Swagger UI, Git, GitKraken, Azure Storage Explorer, Seq, Kibana/ELK, JIRA/Azure Boards, Confluence, Lucidchart, Miro, Octopus, Grafana OnCall, PagerDuty

Legacy/content: IIS, Windows Services, WCF (maintenance/migration), Sitecore/Umbraco (familiarity) PROFESSIONAL EXPERIENCE

Lead .NET Engineer / Solutions Architect Aurora Health Analytics — Remote (US) Jul 2021 – Present Healthcare analytics and care-management SaaS

• Led event-storming and domain modeling to decompose a legacy monolith into independently deployable microservices to unblock parallel delivery.

• Built HIPAA-grade ingestion for HL7/FHIR and EDI 837/835 with Azure Functions/Durable orchestrations and Service Bus topics/subscriptions; enabled near-real-time cohort refresh.

• Implemented CQRS with MediatR, EF Core write models, and Dapper projections; improved P95 latency from 1.1s to 380ms and sped up dashboard loads.

• Unified reads with a GraphQL gateway (Hot Chocolate) using DataLoader and persisted queries; reduced payload size and round-trips.

• Centralized identity with OIDC (Azure AD/Entra ID), tenant-aware RBAC/ABAC, and Key Vault secrets; supported SOC 2 Type II with zero critical findings.

• Established GitHub Actions + Helm deployments to AKS (blue/green, canary) with automated migrations and health probes; maintained very low change-failure rate.

• Implemented end-to-end observability (OpenTelemetry traces/metrics/logs, correlation IDs); tuned SLOs and reduced alert noise; MTTR fell to <30 minutes.

• Optimized Azure spend via right-sizing, SQL tier tuning, pool/connection tuning, cache hit-ratio improve- ments, and KEDA autoscaling tied to golden signals.

• Piloted Azure Cognitive Services/Azure OpenAI behind private endpoints for PHI-safe OCR/classification/summarizati to speed back-office workflows.

• Delivered DR with geo-replication, automated backups, and practiced runbooks; validated RPO in minutes and RTO within one hour through recurring game-days.

• Standardized API versioning, error contracts, pagination, idempotency keys, and health endpoints; introduced PR checklists and performance budgets.

• Reduced integration breakages with contract testing (Pact) and post-deploy verification using feature flags and canary analysis; enabled quick rollbacks.

Tech stack: C#, .NET 6/7/8, ASP.NET Core, EF Core, MediatR, MassTransit, GraphQL/Hot Chocolate, Azure AKS/Functions/Service Bus/APIM/Key Vault/App Insights/Storage, Redis, SQL Server, Cosmos DB, Terraform, GitHub Actions, Helm, OpenTelemetry, Serilog, Grafana, Pact, Playwright Senior .NET Developer / Tech Lead HarborView Financial Systems — New York, NY (Remote) May 2018 – Jun 2021

FinTech trading and compliance products

• Replaced WCF endpoints with ASP.NET Core Web APIs and gRPC streaming with backpressure to sustain high-volume market data and accelerate partner onboarding.

• Executed a strangler-fig migration for IIS/WCF workloads to Azure App Service/AKS while preserving uptime and cutting maintenance toil.

• Implemented Kafka-based event settlement with an outbox pattern for exactly-once semantics; simplified audits and reduced reconciliation defects.

• Met FINRA/SEC retention with policy-based authorization and WORM storage; added tamper-evident log- ging and full auditability.

• Integrated Stripe billing with idempotency keys, retries, and DLQ handling; materially lowered payment failures and support tickets.

• Improved performance with Redis caching, response compression, compiled queries, and targeted indexing; P95 latency 480ms 160ms and lower SQL DTUs.

• Shipped multi-stage CI/CD in Azure DevOps with environment gates, Helm charts, and smoke/perf checks; shortened lead time from days to hours.

• Delivered SSRS/Power BI regulatory reports and mail-merge exports to streamline audits and client commu- nications.

• Prevented reliability/security regressions with SonarQube quality gates and Roslyn analyzers; raised baseline code health.

Tech stack: C#, .NET Core, ASP.NET Core, EF Core, Dapper, gRPC, Kafka, Redis, SQL Server, SSRS, Power BI, Azure DevOps, App Service/IIS, AKS, Helm, Key Vault, SonarQube, Octopus

.NET Developer BlueRidge Freight Technologies — Austin, TX Mar 2014 – Apr 2018 Logistics and fleet optimization SaaS

• Built multi-tenant TMS modules (orders, routing, driver APIs, notifications) with strict tenant isolation and row-level security.

• Created Hangfire jobs for route optimization, OCR/POD ingestion, and scheduled notifications; improved delivery reliability and back-office throughput.

• Applied CQRS with Dapper read models for dashboards; partitioned reads to sustain peak traffic with con- sistently fast loads.

• Added policy-based authorization and SSO via Azure AD; enforced least-privilege across modules.

• Optimized EF queries, indexes, and caching; increased throughput while reducing DB load.

• Maintained legacy .NET/IIS components and automated deployments; contributed to an Angular dispatch dashboard to accelerate triage.

• Instrumented structured logging and baseline metrics; shortened time-to-diagnose production issues.

• Authored deployment runbooks and rollback checklists to reduce release risk; prepared for .NET Framework

.NET Core migration.

Tech stack: C#, .NET Framework .NET Core, ASP.NET MVC/Web API, EF6 EF Core, Dapper, Hangfire, SQL Server, Redis, Azure App Service/Storage, Angular, Bootstrap, Jenkins, IIS KEY PROJECTS

• Claims & adjudication service (healthcare): CQRS claims engine with EF Core, MediatR, auditable workflows; EDI 837/835 export.

• GraphQL API gateway: Hot Chocolate + DataLoader + persisted queries to unify read models and reduce client chattiness.

• Real-time notifications hub: SignalR with per-tenant throttling, rate limiting, and SendGrid/Twilio in- tegrations.

• Document pipeline: Azure Functions/Durable orchestrations for OCR/classification, blob triggers, poison- queue handling, deterministic reprocessing.

• Reliability program: SLOs/SLIs with OpenTelemetry + Grafana/Datadog/Sentry, runbooks/playbooks, chaos drills; MTTR improved to <30 minutes.

• Cost governance toolkit: right-sizing, SQL tier tuning, cache optimization, and KEDA autoscaling tied to golden signals.

EDUCATION

Bachelor of Science in Computer Science

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