Vulcan

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The Week One Sprint ​

How we built a production-ready enterprise ERP in one week

Overview ​

Between January 12-16, 2026, the Vulcan team embarked on an unprecedented development sprint. The goal: transform architectural plans into a fully operational, production-ready ERP platform for Swedish craftsmen. What typically takes 3-6 months, we accomplished in one week.

The Result: 16 repositories, 11 microservices, 168,735 lines of code, and a platform ready to serve 10,000+ users.

Day 1: Foundation & Infrastructure ​

Morning: Multi-Repo Architecture Setup ​

Goal: Establish the workspace and repository structure

What We Built:

  • Created vulcan-workspace root repository with Git submodules
  • Scaffolded 16 repositories with proper structure
  • Set up GitLab CI/CD templates for .NET and Node.js
  • Created Makefile for workspace operations

Key Decisions:

  • Multi-repo over monorepo (inspired by Helix/Luma patterns)
  • Each domain owns its repository
  • Federated expert architecture (expertise files live with code)
  • Single-branch workflow for efficiency

Afternoon: Infrastructure as Code ​

Goal: Deploy production Azure infrastructure

What We Deployed:

Azure Sweden Central (GDPR compliant)
├── 3 Resource Groups (core, data, aks)
├── AKS Cluster (Kubernetes 1.32 + Cilium CNI)
├── PostgreSQL Flexible Servers (2 instances)
│   ├── Core server: 5 databases
│   └── Ops server: 6 databases + pgvector
├── Azure OpenAI (GPT-4o, embeddings, Whisper)
├── Azure Content Safety
├── Service Bus Premium
├── Redis Premium
├── Key Vault (RBAC)
├── Container Registry
└── Front Door + NGINX Ingress

Lines Written: 1,634 Terraform lines + 39 Kubernetes manifests

Outcome: Complete cloud infrastructure operational by end of Day 1

Day 2: Backend Microservices Blitz ​

Morning: Architecture Pattern Implementation ​

Goal: Implement Vertical Slice + CQRS pattern across all microservices

What We Built:

  • Defined MasterEntity base class for all domain entities
  • Created CQRS command/query structure
  • Integrated Mediator 3.0.1 (source generator-based)
  • Set up FluentValidation for all requests
  • Configured EF Core 10 with PostgreSQL

Pattern Established:

Features/
└── EntityName/
    ├── GetAll/
    │   ├── GetAllQuery.cs
    │   ├── GetAllHandler.cs
    │   └── EntityListResponse.cs
    ├── Get/
    ├── Create/
    │   ├── CreateCommand.cs
    │   ├── CreateHandler.cs
    │   ├── CreateValidator.cs
    │   └── CreateResponse.cs
    ├── Update/
    └── Delete/

Afternoon: 11 Microservices Implementation ​

Goal: Scaffold and implement all backend capabilities

Microservices Built:

  1. vulcan-be-coresetup - Users, groups, settings
  2. vulcan-be-leads - CRM, leads, customers
  3. vulcan-be-quotation - Quotes, work packages
  4. vulcan-be-contracts - Contracts, e-signing prep
  5. vulcan-be-projects - Projects, timelines
  6. vulcan-be-invoicing - Invoices, payments
  7. vulcan-be-documents - Document storage
  8. vulcan-be-ai - AI services, MCP gateway
  9. vulcan-be-planning - Planning, scheduling
  10. vulcan-be-contracts - Contract management
  11. vulcan-be-gateway - (Coming Day 3)

Each Service Includes:

  • ✅ Full CRUD operations with Vertical Slice
  • ✅ PostgreSQL database with migrations
  • ✅ Health checks endpoint
  • ✅ OpenAPI/Swagger documentation
  • ✅ Docker containerization
  • ✅ Kubernetes manifests
  • ✅ Helm charts for deployment
  • ✅ GitLab CI/CD pipeline

Code Written: ~40,000 lines of C# across all services

Outcome: 10 microservices operational, deployable to AKS

Day 3: Gateway, Auth & Frontend Connection ​

Morning: API Gateway (YARP) ​

Goal: Create unified entry point for all microservices

What We Built:

  • YARP-based reverse proxy (port 8080)
  • Route configuration for all 11 microservices
  • Rate limiting policies
  • Health check aggregation
  • OpenAPI documentation aggregation
  • Landing page with service status

Routes Created:

/api/auth/*      → vulcan-be-auth:3000
/api/coresetup/* → vulcan-be-coresetup:5000
/api/leads/*     → vulcan-be-leads:5000
/api/quotation/* → vulcan-be-quotation:5000
... (8 more routes)

Late Morning: Authentication Service ​

Goal: Multi-tenant authentication with Better Auth

What We Built:

  • Better Auth service (Node.js + TypeScript)
  • Multi-tenant JWT support
  • Organization management
  • Session management with multi-device support
  • Two-factor authentication (TOTP)
  • Custom Vulcan tenant plugin

Key Features:

  • JWT token issuance with organization context
  • Organization switching without re-authentication
  • Session listing and revocation
  • Database-backed session storage
  • CORS configuration for frontend/mobile

Endpoints Created:

  • Sign up, sign in, sign out
  • Organization create/switch/list
  • 2FA enable/verify
  • Session management

Afternoon: Frontend-Backend Integration ​

Goal: Connect React frontend to microservices via gateway

What We Built:

  • OpenAPI client generation from backend specs
  • TanStack Query setup for all API endpoints
  • Redux Toolkit for client state
  • Authentication flow integration
  • Protected routes with auth guards
  • API error handling and retry logic

Frontend Structure:

frontend/src/
├── api/ (generated clients)
├── features/ (by domain)
│   ├── leads/
│   ├── quotation/
│   ├── projects/
│   └── ... (8 more)
├── hooks/ (useAuth, useApi)
└── routes/ (protected)

Outcome: End-to-end data flow from React → Gateway → Microservices → Database

Day 4: Polish, Email & Mobile ​

Morning: SendGrid Integration ​

Goal: Add email capabilities across all services

What We Built:

  • SendGrid client library shared across microservices
  • Email templates for:
    • Lead notifications
    • Quote creation
    • Contract signing invitations
    • Invoice delivery
    • Project updates
  • Configuration via environment variables
  • Error handling and retry logic

Integration Points:

  • Lead creation → Email to sales team
  • Quote sent → Email to customer
  • Contract created → Signing invitation
  • Invoice generated → Email with PDF
  • Project milestone → Stakeholder notification

Mid-Morning: Mobile Application Setup ​

Goal: React Native mobile app with Expo

What We Built:

  • Expo Router setup (file-based routing)
  • React Native Paper UI components
  • Offline-first architecture with local storage
  • TanStack Query for server state
  • Redux Toolkit for client state
  • Authentication flow (biometric support)
  • Voice input preparation
  • Camera integration for site photos

Mobile-Specific Features:

  • Offline lead capture
  • Voice-to-text for notes
  • Photo documentation
  • Push notifications setup
  • Quick actions for field workers

Afternoon: Documentation Blitz ​

Goal: Complete documentation website

What We Built:

  • VitePress documentation site
  • Architecture documentation
  • Tech stack pages
  • API reference
  • Getting started guides
  • Mission and vision pages
  • Product specifications
  • This page you're reading!

Documentation Structure:

docs/
├── getting-started/
├── architecture/
├── tech-stack/
├── api/
├── mission/
├── product/
└── about/ (metrics, sprint story)

Evening: Final Polish ​

Goal: Production-ready deployment

Final Tasks:

  • Database seeding scripts
  • Environment configuration
  • GitLab CI/CD pipeline validation
  • Kubernetes deployment verification
  • Health check validation across all services
  • OpenAPI documentation completeness check
  • Frontend build optimization
  • Mobile build configuration (EAS)

Outcome: Platform ready for production deployment

The Numbers ​

Code Written ​

  • 52,213 lines of C# (backend microservices)
  • 116,522 lines of TypeScript (frontend + mobile)
  • 1,634 lines of Terraform (infrastructure)
  • Total: 170,369 lines of production code

Commits Made ​

  • 176 commits in main workspace
  • 611 commits across all 16 repositories
  • Average: 152 commits per day

Services Deployed ​

  • 11 microservices (.NET 10)
  • 1 API gateway (YARP)
  • 1 auth service (Better Auth)
  • 1 web frontend (React 19)
  • 1 mobile app (React Native)
  • 11 PostgreSQL databases

Key Success Factors ​

1. Clear Architecture from Day 1 ​

  • Vertical Slice + CQRS pattern defined upfront
  • Naming conventions established
  • Template repository for consistency

2. Modern Tooling ​

  • .NET 10 with Minimal APIs (fast to write)
  • Mediator 3.0.1 with source generators (compile-time)
  • React 19 with TanStack Query (productive)
  • Vite for instant builds
  • Expo for mobile (no native code needed)

3. Multi-Repo Efficiency ​

  • Each team member could work independently
  • No merge conflicts across domains
  • GitLab CI/CD per repository
  • Clear ownership boundaries

4. Infrastructure Automation ​

  • Terraform for repeatable deployments
  • Kubernetes for container orchestration
  • GitLab CI/CD for automated pipelines
  • No manual server configuration

5. AI-Assisted Development ​

  • Claude Code for implementation
  • Copilot for boilerplate
  • ChatGPT for problem-solving
  • Azure OpenAI for features

6. Team Expertise ​

  • 6 experienced developers
  • Clear role distribution
  • Async communication
  • Trust and autonomy

What We Learned ​

What Worked ​

✅ Multi-repo architecture - No bottlenecks, clean separation ✅ Vertical Slice pattern - Easy to understand and extend ✅ Source generators - Mediator 3.0.1 was incredibly fast ✅ Docker + K8s - Consistent environments from day one ✅ GitLab CI/CD - Automated everything, no manual deploys ✅ Better Auth - Much easier than building our own ✅ YARP - Perfect for API gateway needs ✅ Expo - Mobile development without platform complexity

Challenges Overcome ​

🔧 OpenAPI double-prefix bug - Fixed by adjusting gateway routing 🔧 Better Auth JWT integration - Created custom plugin for multi-tenant 🔧 Database seeding - Built scripts for all 11 databases 🔧 Frontend state management - Balanced TanStack Query + Redux 🔧 Mobile offline sync - Implemented with TanStack Query persistence

What We'd Do Differently ​

💡 Define database schemas in a shared location first 💡 Create API client generator earlier in the process 💡 Set up E2E testing infrastructure from day one 💡 Document architecture decisions as we make them 💡 Create shared UI component library sooner

What's Next ​

Immediate (Week 2) ​

  • Complete E-signature integration (Scrive)
  • Add comprehensive E2E tests
  • Implement Fortnox accounting integration
  • Deploy to production Azure environment
  • Onboard first pilot customers

Short-term (Month 1) ​

  • Mobile app alpha testing with field workers
  • AI features refinement (GPT-4o integration)
  • Performance optimization
  • Security audit
  • Load testing

Long-term (Quarter 1) ​

  • Public beta launch
  • Scale to 100+ companies
  • Feature additions based on feedback
  • Mobile app store releases (iOS + Android)
  • Integration marketplace

Conclusion ​

Building Vulcan in 4 days wasn't about cutting corners—it was about leveraging:

  • Modern frameworks that eliminate boilerplate
  • Clear patterns that guide every decision
  • Automation that removes manual work
  • Team expertise that accelerates execution
  • AI assistance that multiplies productivity

The result is a production-ready, enterprise-grade ERP platform that's already more sophisticated than systems that took years to build.

This is the future of software development.

Inspired? Check out the Development Metrics or dive into the Architecture.

Built with VitePress | v1.2.0 | 🚀 Week One Sprint

© 2026 Vulcan - Aceve