Web applications, integrations and .NET + React architecture
My name is Dariusz Lenartowicz. I design and build systems that process hundreds of thousands of events a day and have been in production for over a decade. You talk directly to the person who writes the code and owns the architecture - I assemble the team per project.
I've run Softio since 2008. This is not an agency with a layer of account managers and PMs - you talk to the person who designs the architecture, writes the code and answers for the result. When a project calls for it, I bring in proven subcontractors and lead them as the technical lead.
That model delivers something neither a large software house nor a solo freelancer can copy: one person accountable for the whole life cycle of a system - from analysis, through architecture and delivery, to years of production maintenance.
The scope is deliberately narrow. Each of these services is backed by systems running in production - not by slides.
From analysis and architecture, through development, to production rollout and years of stable operation under load.
I connect systems that don't talk to each other: ERP, CRM, WMS, payments, partner panels and devices in the field.
Architecture and code audits, technology advisory, and reinforcing your team for the duration of a project.
Microsoft stack on the server, React in the browser, architectural patterns proven in production.
A selection of projects I have delivered over the years.
Softio in-house product
A single face photo turns into a printed, bound book - illustrated prose or a comic - in which the person receiving it is the hero of almost every illustration. The creator walks through eleven steps with no account required, and a preview of the book is generated before any payment.
My role: everything - product, architecture, and delivery. A modular .NET monolith with a separate PostgreSQL schema per module, two React/Vite front ends on their own origins, a background job queue, and illustrations generated by Gemini.
P2P2 Sp. z o.o.
A SaaS platform for working-time management and productivity measurement: attendance registration (cards, QR codes, mobile devices), schedules, overtime, requests, compliance reports, and measurement of activities that WMS and ERP systems never see. Real-time dashboards, multiple time zones, integrations with WMS/ERP and payroll systems.
My role: lead architect and team leader. Event Driven + CQRS architecture, live data from Android terminals and/or integrations.
PKS Polonus S.A.
A central multi-channel bus-ticketing system - the search and online checkout are only the surface. Underneath: bus-station and fleet management, an agency sales panel, fleet monitoring at third-party vendors, and integrations. On top of that, a dedicated application for selling tickets at the station's ticket counters.
GEODIS Road Network (BŁONIE)
The full range of Softio services at a single client: building systems and applications, integrating systems with each other, architecture advisory, plus support and maintenance. The best evidence that the “one partner for the whole system life cycle” model works in practice.
P2P2 Sp. z o.o.
Monitoring of forklifts and machines. Every day it queued, processed and aggregated hundreds of thousands of device messages and presented them in reports and charts.
If you have a system to build, take over or fix - get in touch.
Email or phone works best - I answer personally. I run ongoing engagements in parallel, so new projects are planned ahead and I'll tell you plainly when I can realistically start.