Finance and fintech
Fintech software development: CRM, client portals and KSeF integration
For financial advisory firms, companies billing subscriptions, fintech startups and accounting offices. I build and rebuild apps where every number counts: CRMs for advisers, client portals, billing and integrations with KSeF, Poland's national e-invoicing system. The goal is less manual retyping and fewer errors before they reach the client.
- 12+
- years in websites, apps and marketing
- 150+
- projects: I help at every stage, from idea to growth
- 2–6 wks
- from idea to a working product
- 2 h
- usual time to my reply
How I approach it
In financial software, a mistyped amount isn't a small bug, it's a correction, a complaint or a client's lost trust. That's why I design forms and processes so that mistakes are hard to make: data checked as it's entered, data from one source instead of retyping, and automated tests on every path that touches money.
Many financial companies run on spreadsheets, several programs that don't talk to each other, and email. I start where the team loses the most time and where errors appear. I sign an NDA, and security, permissions and data access are part of the project from day one. I lead the project, I'm accountable for the result and I'm your single point of contact. For complex, specialist questions, such as infrastructure or regulatory requirements, I bring in trusted experts.
Recommended services
Where to start
Web app and CRM
A CRM for advisers, a client portal or a billing tool that fits the way you work. €20,000–46,500, in phases.
→SaaS product for finance
A fintech startup or a subscription service: a first version for €1,900–9,300 at a fixed price, usually 2 to 6 weeks.
→KSeF integration
Invoices from your software, store or system go to Poland's KSeF automatically. A ready-made integration or a custom one via the API, individual quote.
→Application security
A review of sign-in, permissions, forms and configuration, a prioritised report and fixes. Fixed price once the scope is agreed.
→Product support
After launch: updates, fixes and new features, with one person who knows your code. Individual quote.
→How I work with this
How we work together
- 01
A call and an NDA: what data you handle, who uses it and where errors appear
- 02
A review of your current tools, data and connections to other systems
- 03
A phased plan with the price and timeline in writing, starting with what saves the most time
- 04
The build with tests on financial paths, rollout and support after launch
What clients say
„We worked with Vlad on a Next.js project. He knew what he was doing from day one, didn't overcomplicate things and came up with better approaches on his own. I especially value his work on the site's performance. Everything was delivered as agreed.”
George B. CEO, finance company
„We needed to build an MVP fast to test our idea in practice. Vlad helped us choose sensible solutions and focus on what we really needed for launch. We didn't try to build everything at once, yet he made sure the project could grow later without starting from scratch.”
Alex N. Product Manager at StartupX
„Vlad got up to speed with our project quickly and pointed out several problems we hadn't treated as priorities. He sorted out our database and security issues. I liked that he didn't just complete tasks but clearly explained why something was worth changing and what the consequences could be.”
Michał R. CTO at TechCorp
„We had an app where every bigger change was becoming a problem. Vlad helped us clean up the code, rebuild some of the older parts and introduce automated tests. Working on new features is much easier now. I also appreciate his patience in explaining technical topics to people outside the development team.”
Sara K. Product Owner at WebSolutions
Want less manual work and fewer errors?
Describe in a few sentences how your team works today and which tools it uses. If you like, I'll sign an NDA first. I usually reply within 2 hours, and within one working day I tell you where to start.
Frequently asked questions
How much does an app for a financial company cost?
A web app for a business, such as a CRM for advisers or a client portal, costs €20,000–46,500 and is built in phases, usually from 6 weeks. The price grows with the number of roles, integrations and reports. If you want to test the idea first, a first version of the product costs €1,900–9,300.
Off-the-shelf or custom CRM for financial advisers?
If an off-the-shelf CRM does what you need, choose it, it will be cheaper. A custom CRM makes sense when you have unusual products, commissions or billing, when you pay for several tools that don't talk to each other, or when workarounds cost the team hours every week. On the first call I'll tell you honestly which option fits.
Do you build software for accounting offices?
Yes, when ready-made programs don't cover your work: for example a portal where clients upload documents, deadline reminders or connecting several programs so data isn't retyped. Replacing the accounting software itself usually doesn't make sense. I connect it to the rest of the process.
How much does a KSeF integration cost?
Setting up a ready-made plugin or invoicing program takes from 1 working day. A store integration with corrections and returns, or an integration with the KSeF API for your own system or ERP, takes from 1–2 weeks. I quote each option individually once I know your system.
How do you keep financial data secure?
I sign an NDA, and the code, accounts and servers belong to you. We agree sign-in, roles and data access at the start of the project, and I cover the most important flows with automated tests. If the project needs a formal penetration test or certification, I say so plainly and help prepare the app for working with a specialist firm.
What if you're unavailable?
The code, accounts and documentation are yours from day one and live in your repository. I document the architecture and decisions, so another developer or your team can take the app over. You can also keep me on monthly product support.