Projects

A selection of backend projects and professional work focused on scalable services, API design and event-driven architectures.

My experience includes freelance engagements and production systems built for real-world usage.

Event-Driven Microservices Platform (QRaGo)

Design and implementation of backend microservices for a logistics platform with an emphasis on event-driven workflows and service boundaries.

Architected domain workflows using CQRS-style patterns and event-driven communication between services.

Highlights

• Microservice architecture design
• Event-driven workflows
• CQRS and event sourcing concepts
• API development for internal and external consumers
• Production system reliability improvements

Stack

Go · Node.js · MongoDB · Redis · Microservices

Focus

Distributed systems, architecture design, scalability

Core API Platform (jooli)

Backend development for core application services including REST APIs, API contracts and automated testing infrastructure.

Established testing strategies and improved development reliability through automated validation pipelines.

Highlights

• REST API design and implementation
• OpenAPI specification authoring
• Automated unit and end-to-end testing
• Backend architecture improvements
• Performance and reliability enhancements

Stack

Node.js · NestJS · MySQL · Redis · OpenAPI · Testcontainers

Focus

API design, backend architecture, quality engineering

GraphQL Integration Layer (Weisse Liste)

Development of backend services and a GraphQL proxy layer to integrate and aggregate multiple external APIs into a unified system.

Highlights

• GraphQL aggregation layer
• External API integration
• Backend service development
• Data transformation and orchestration

Stack

Node.js · TypeScript · Express · GraphQL

Focus

API integration, service orchestration, backend design

Additional Experience

Additional freelance and professional work across a range of projects, including backend systems, frontend applications and fullstack product development.

Includes

• Backend architecture and API development for web platforms
• Frontend implementation using modern TypeScript frameworks
• Rapid prototyping for startups and product teams
• Integration of third-party services and external APIs
• Collaboration across product, design and engineering teams
• Performance improvements and reliability enhancements in existing systems

Stack

Node.js · NestJs · TypeScript/Javascript · React · VueJS · MySQL · NoSQL

Architecture Interests

Areas I am particularly interested in:

• Distributed systems design
• Event-driven architectures
• Backend reliability and observability
• API design and developer experience
• Performance-critical backend services

Freelance Availability

I am available for backend freelance projects with a focus on:

• Go backend services
• Node.js / TypeScript backends
• System architecture and design
• API development
• Performance and reliability improvements

Contact: hallo[at]nicholasbraun[dot]de