Sites, projects & devices
- Full registry of customer sites and installed equipment
- Map view with a multi-stop route planner for service trips
- Component catalog with pressure-equipment data
- Data-completeness tracking per device type
Case study · Suomen Tekojää Oy · 2026
One platform for the sites, machines and people behind cold.
Suomen Tekojää Oy is a Finnish engineering company that builds ice rinks, heat pumps and cold-storage systems, and it had dedicated tools for each part of its work. I designed and built a single platform that brings them together and goes further: fleet management, live machine telemetry, service work, project delivery, customer access and an AI assistant that works with the company's own data.
Lead developer & architect
Hosting & operations
In daily production use
The goal
Everything about a site, in one place
The company already had working tools for each job. The aim was to connect them, so that each piece of information is entered once and is available wherever it is needed.
One shared record
Sites, devices, components, service history and project documents are linked together, so the full history of an ice rink is a single click away.
Machine data where the work happens
Alarms and trends from the controllers at customer sites appear next to the tickets and service history of the same equipment, for everyone who works on it.
Smoother service and delivery
Tickets, visit reports, commissioning checklists and project plans follow the same templates, and customers can follow the work done for them.
What it does
Nine areas, one shared data model
Each area is a full feature set in daily use, built on the same permissions, audit trail and real-time event system.
Live data from field controllers
- Data collection from industrial controllers at customer sites
- Controller alarms automatically open service tickets
- Trends and status history per device
- Easy installation and automatic updates for site PCs
Tickets & work reports
- Ticketing with priorities, assignment, photos and comments
- Template-driven work reports with PDF export
- Visit scheduling and IO commissioning checklists
Project plans
- Task trees with dependencies that unlock work in order
- Gantt timeline and rolled-up progress per stage
- Phone-first view for installers on site
- Report review and approval workflow
Assistant on company data
- Tool-calling LLM agent that queries sites, devices, tickets, energy prices and weather
- Proposed changes are staged and confirmed by the user before saving
- Semantic search (RAG) that respects each user's access rights
- Works with both cloud and locally hosted language models
Customer portal
- Separate internet-facing app for the company's customers
- Customers see only the sites granted to them
- Service requests and two-way messaging with staff
- Kept separate from the company's internal systems
Real-time teamwork
- Direct and group chat with files, reactions, mentions and links to records
- Notifications by inbox, email and push
- Internal wiki with access control
- Installable app with a desktop-style window workspace
Energy & design tools
- Electricity spot prices at 15-minute resolution
- Weather forecasts and history for every site
- Ice-rink thermal design calculator with brine and refrigerant property tables (ammonia, glycols, ethanol)
- PLC IO configuration generator
Security & compliance
- Role-based access down to individual sites and files
- Complete audit trail of data changes, nearly 100,000 recorded so far
- Encrypted file storage
- Automated security monitoring and reporting
How it fits together
From the machine room to the browser
A simplified view. Data comes in from the field and from external services, passes through one API that enforces permissions, and reaches each audience through its own front end.
Inputs
Field controllersPLCs at rinks and plants
Energy & weatherSpot prices, forecasts
CRMCustomer records sync
Core
Platform API
Business logic, access control, audit trail, background workers, real-time events
- .NET
- PostgreSQL
- Real-time events
Audiences
Staff web appOffice, field technicians, management
Customer portalSite owners and operators
AI assistantCloud or local language models
How it was built
Engineering practices
Security by default
Access rights are checked on every record a user reads or changes, personal data is protected in the interface, and the system is reviewed for security regularly.
Self-hosted operations
The platform runs in containers on the company's own servers, with scripted deployments, versioned releases, encrypted backups and a separate test environment.
Clear boundaries
A shared domain model, one API that handles all business logic, and separate front ends for staff and customers that only talk to that API.
Tested and observable
Automated test suite in CI, a catalog of error codes that users can quote to support, incident tracking, usage telemetry and a live status panel.
Built with its users
Features were shaped with technicians, project managers and office staff. The whole UI is localised in Finnish and English, with eight themes and a mobile-first view for field work.
AI-assisted development
An agentic coding workflow backed by maintained architecture documentation, so that every change follows the same invariants and conventions.
Technology
Stack
Application
C# / .NET 10ASP.NET CoreBlazorEF CoreSignalRJavaScriptPWA
Data
PostgreSQLpgvectorTimeseriesAudit logging
AI & integration
Claude APIOllamaRAGTool callingPythonBeckhoff ADSMicrosoft Entra IDREST APIs
Infrastructure
DockerNginxLinuxNVIDIA GPUGitHub ActionsBashNode.js