Blog
Knowledge on custom software
C3S knowledge base: how much a custom app costs, what the delivery process looks like, which technologies to choose and what happens after launch.
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Industry ·
uksc.pl - is your company covered by Poland's Cybersecurity Act? A one-minute qualifier
We built a qualifier that uses a company's KRS number to assess whether it is an essential entity, an important entity or outside the scope of Poland's Cybersecurity Act (UKSC) - with a legal rationale and an audit-ready PDF report.
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Technology ·
A new site from an AI builder - what next?
An AI builder gives you a site in an hour. The real problems start after launch: hosting, domain, email, SEO, GDPR, performance and ownership. What actually sits behind a website and what to take care of.
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Technology ·
Vercel, Render, and the client held hostage
Why more and more companies suddenly pay a subscription in dollars for a website that ran fine on hosting they had already paid for. How to tell a sensible migration from plain incompetence, and what to ask before you hand anyone access to your DNS.
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Technology ·
How we refreshed consaldi.pl - a professional look, and a site that does not slow down
The consaldi.pl website refresh: how we combined a professional, rich look with real speed and strong PageSpeed results, and why we optimized it for AI engines (LLMs).
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Industry ·
From Excel to a Dedicated CRM - a System for a Key Account Manager
We replaced a sprawling Excel workbook with a dedicated CRM application: a contact timeline, a sales pipeline, automated reports and a separate management panel. One source of truth instead of seven tabs.
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Industry ·
localscope.pl - check the location before you sign the lease
A free tool that scores an address for your business in under a minute: real walking reach, residents, competition and a transparent 0-100 potential score.
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Technology ·
Wrocław in 3D over a single weekend - the wro3d.pl case study
How a photorealistic 3D map of Wrocław with a voice guide was built in one weekend: Google 3D Maps, MapLibre, an ElevenLabs voice clone and lessons from working with AI.
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Case study ·
A calculator that turned product-matching emails into a tool engineers reach for every day
KUVER GmbH, a Berlin manufacturer of flexible high-current connections, had a problem common to many technical B2B companies: customers didn't know which product matched their requirements. We built an online calculator - and it became one of the most frequently used tools among electricians and installation designers across Europe.
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Case study ·
13 stands, zero paperwork - how we replaced a daily sheet with a live operations system
A produce business running more than a dozen field stands was reconciling every day on a handwritten sheet. We built them a web app that moves the entire workflow - from morning stock allocation to end-of-day cash close - onto a phone and a desktop dashboard.
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Process & quality ·
5 mistakes when commissioning an app that cost companies the most
Five of the most common and most expensive mistakes when commissioning a custom app - and how to avoid them. Practical experience from the C3S.PL studio.
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Process & quality ·
What happens to an application after launch? Maintenance, development, costs
What application maintenance after launch covers, how much it costs, what iterative development looks like and why monitoring is essential. A C3S.PL guide.
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Process & quality ·
What working with a boutique studio looks like - how we differ from a large software house
How a boutique studio differs from a large software house, what the process looks like, who actually writes the code and who it is a good choice for. An explanation by C3S.PL.
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Technology ·
Integrating a system with email, invoicing and payments - how we tie it together
The most common integrations for custom applications, how we tie them together, what drives up the cost and which pitfalls to avoid. Practice from the C3S.PL studio.
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Technology ·
Data security in a custom application - what you need to know before deployment
Data location, roles and access, RODO (GDPR) in practice - what to check before deploying a custom application. A C3S.PL guide.
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Technology ·
Why We Build with Next.js + Supabase - and When This Stack Falls Short
Why we choose Next.js and Supabase for custom applications, what benefits this brings the client, and when it is better to reach for a different stack. Explained by C3S.PL.
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Technology ·
What is a PWA and why it is often cheaper than a native app
A definition of a PWA, how it differs from a website and a native app, its advantages, limitations and when to choose it. Explained by the C3S.PL studio.
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Industry ·
Compliance documentation system (QR, photos, geolocation) for clinics and food service
How a system for documenting tasks and inspections via QR, photo and geolocation works, which industries it suits and what it looks like from the employee's side. A C3S.PL guide.
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Industry ·
Dedicated CRM for B2B Sales - What an Outbound System Should Have
What ready-made CRMs lack, what an outbound and cold calling system should have, and when to build your own. A C3S.PL guide.
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Industry ·
PWA for a Small Business - How It Differs from a Website and a Store App
What a PWA is, how it differs from a regular website and a native app, when it is enough, and how much it costs compared to a store app. A guide by C3S.PL.
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Industry ·
Stall sales management system - the features you need
What features a stall sales system should have: settlements, roles, reports, offline work. Based on a real C3S.PL implementation.
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Costs & decision ·
Software house or freelancer? What to choose for a custom project
What a freelancer offers, what a studio offers, where the risk lies and how to choose a contractor for your project. A practical C3S.PL guide.
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Costs & decision ·
Migrating from Excel to a dedicated system - when does a company need it
5 signals that a company has outgrown Excel, what you gain after migration and how to move data safely. A C3S.PL guide.
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Costs & decision ·
App MVP in 6 Weeks - What You Can Realistically Build
What can be built in 4-6 weeks, how to cut MVP scope and what to avoid. Practice from the C3S.PL studio.
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Costs & decision ·
Custom App or Off-the-Shelf System? When Custom Pays Off
Practical criteria for choosing between a custom application and a ready-made SaaS. When it pays to build your own, and when it does not. A C3S.PL guide.
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Costs & decision ·
How Much Does a Custom App Cost in 2026? Realistic Price Ranges
What really drives the price of a custom app, what the price ranges are, and how to avoid overpaying. Concrete cost factors from the C3S.PL studio.
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Guide ·
Custom Application: A Complete Guide for Businesses (2026)
What a custom application is, how much it costs, when it pays off and what the implementation process looks like. A complete guide from the C3S.PL studio.