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Oussama HammamiOH

Oussama Hammami

Senior .NET Backend & Distributed Systems Engineer

€550/day
Mannheim, DE
8-15 years

Average response time: 1 hour

About Oussama

Senior .NET backend and distributed-systems engineer with 10+ years building APIs, microservices, and event-driven backends in C#/.NET.
I design and implement scalable services (REST/gRPC, RabbitMQ, SQL/NoSQL) and real-time dashboards using Blazor/SignalR or modern web stacks.
Experience in finance, industry and SaaS: migrations from monolith to microservices, performance tuning, and production troubleshooting.
I can join existing teams or lead specific backend/architecture missions remotely (B2B, EU time zones).
  • English

    Fluent

  • French

    Fluent

  • Arabic

    Native or bilingual

  • German

    Basic

Can work on-site
Mannheim (up to 50km)

Experience

  • Self-initiated project
    Stocksim (OpenSource GitHub)
    August 2025 - Today (10 months)
    Event-driven trading/portfolio simulator built to demonstrate modern .NET 8, messaging, real-time UI, and cloud-native deployment.
    • Designed and implemented a distributed microservices architecture in .NET 8 with DDD, CQRS and outbox pattern.
    • Built real-time trading dashboards using Blazor Server + SignalR (live quotes, orders, executions).
    • Implemented asynchronous messaging with RabbitMQ, including idempotent outbox publishers and consumers.
    • Containerized services with Docker, local k8s (k3d) and automated deploy to Azure Container Apps.
    • Set up observability with OpenTelemetry, Prometheus, Grafana for metrics and tracing.
    Domain Driven Design ASP.NET Core Docker GitHub Microservices Architecture
  • mi-Solutions & Consulting GmbH
    Senior Software Engineer
    October 2021 - December 2025 (4 years and 2 months)
    Hochheim, HE, Germany
    Worked on Prexello, a platform used by industrial facilities for real-time equipment monitoring, predictive maintenance, and anomaly detection.
    • Orchestrated migration of legacy system from monolith to microservices, introducing RabbitMQ for event-driven decoupling and Docker for repeatable deployments, cutting release lead time ~35%.
    • Built a modular dashboard frontend with Razor views and JS modules, integrating Highcharts/Kendo UI for data visualization; introduced decoupled, testable widget lifecycles, improving responsiveness.
    • Led backend architecture with CQRS/MediatR, clean REST APIs, and consistent serialization/mapping; reduced controller-domain coupling and made business logic significantly more testable.
    • Designed a multi-store data layer unifying MongoDB and SQL Server for telemetry and analytics, enabling richer reporting without impacting OLTP performance.
    • Strengthened platform security and reliability with JWT-based RBAC, structured exception handling, async-first patterns, and localized notifications; reduced production error rates by ~28%.
    • Standardized CI/CD with Jenkins multi-stage pipelines and operationalized Sentry for release health and proactive incident response.
    Microservices Architecture SQL CI/CD Management Database Management (e.g., SQL, NoSQL) ASP.NET Core
  • Nexeo Group
    Mid full-stack Engineer
    February 2017 - September 2021 (4 years and 7 months)
    Paris, France
    Consultant backend/full-stack engineer on long-term engagements for major French banks (Natixis, Société Générale), focusing on P&L, reporting, and cross-asset trading platforms.
    • Extended the risk P&L platform with new KPI calculations (stored procedures, C#) wired into Control-M ETL and exposed in a WPF portal, replacing manual spreadsheets with on-demand UI KPIs.

    • Built a C# market-data pipeline from a Hadoop data lake into Sybase IQ, processing 100M+ records/day and eliminated 20+ hours/week of manual P&L data prep.
    • Modernized legacy internal UIs into a SPA-style JavaScript frontend (Ext JS MVC/MVVM), migrating forms and workflows to reusable components with data binding, shared grids/filters, and stronger validation.
    • Worked on a cross-asset trading platform (20+ teams, 200+ devs) with strict quality gates: enforced TDD/BDD, xUnit + SpecFlow tests, and CI-gated PRs via Jenkins, maintaining ~85% coverage and minimizing regressions.
    • Built a self-serve portal for non-technical users to report issues or requests, replacing email-based workflows with structured Azure DevOps integration and rules-based routing; streamlining support, reducing inbox noise, and giving the team a clear, trackable workload.
    • Collaborated in Agile/Kanban teams using planning poker and sprint demos; also handled night-shift support to diagnose and prioritize P&L issues and coordinate fixes with stakeholders.
    ETL (Extract, Transform, Load) Processes C# SQL Backend Service Development .NET

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Education

  • Diploma
    INSAT - National Institute of Applied Sciences and Technology
    2014
    Diploma
  • Baccalauréat
    Hannibal High School
    2009
    Baccalauréat

Skill set

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