Ionuț-Cristian Florescu
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Ionuț-Cristian Florescu · Bucharest, Romania, EU

Hands-on fractional CTO, product builder and open‑source author.

I take software products from a blank repo to production, and stay to run them for a decade. I still write production code; I've also learned which code isn't worth writing.

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Portrait of Ionuț-Cristian Florescu
  • 28+ yearsbuilding for the web, starting in a Bucharest Internet café in 1998
  • Since 2013technical partner in an online automotive marketplace
  • 940knpm downloads a month for my open-source packages
  • 4,067GitHub stars on my open-source projects

What I offer

A senior technical partner who still writes the code

Financial independence means I pick projects for the problem and the people, and I'll tell you when something isn't worth building.

  • Fractional CTO & technical partner

    For early-stage products that need a senior person to own the technical side: architecture, code, infrastructure, data and day-to-day operations. I treat software as a business asset, not a ticket queue.

  • Sweat-equity partnerships

    If the business side is covered and you need a technical co-owner, I'm open to trading equity for work, with me owning the technical side end to end. It's how I've worked with LeasingSH.ro since 2013.

  • Selected hands-on work

    TypeScript, React, TanStack Start / Next.js, Node.js / Bun and PostgreSQL. Data-rich interfaces are home turf: I wrote Mantine DataTable, used by teams at Microsoft and Namecheap.

  • Built to last

    Less code, fewer moving parts, technologies chosen for the next five years rather than the next conference talk.

  • Rule-heavy domains

    Insurance, leasing, tax: I'm at home where “almost right” means wrong, and every rule has to be traced to its source.

  • No cloud bill to dread

    I self-host what I build, with Docker and Caddy on a plain VPS, and keep running it long after launch.

  • AI, without the hype

    I work with AI coding agents every day, and know where they help and where they don't.

Products I build and run

I ship, then I keep shipping

Two products I own the technical side of, from the first commit to the daily operations.

Founder · my own product

swapp.ro

Invoicing and single-entry accounting for Romanian freelancers (PFA, ÎI, PFI) who aren't VAT-registered. You record each transaction once, and everything that follows from it is worked out for you. Built in 2021 for my own books, rebuilt from scratch in 2026, solo, in five months: product, design, code and operations.

  • Invoices sent through ANAF's e-Factura, with supplier invoices collected in the background
  • The mandatory ledgers, always up to date, and the figures for the D212, D390 and D301 returns, with their due dates
  • Help on every screen that explains the tax rule and cites the article of law
  • 1,200+ unit tests and Playwright end-to-end tests; live since October 2026, and I keep my own books in it
  • TypeScript
  • TanStack Start
  • React
  • tRPC
  • Drizzle
  • PostgreSQL
  • Bun
  • Docker
  • Caddy

Technical partner & fractional CTO · since 2013

LeasingSH.ro

Romania's first online marketplace for new and used cars in leasing or for cash, live since 2010. I took over the technical side in 2013 as a sweat-equity partner and have owned it end to end since. I've rebuilt it three times as the web evolved, keeping the business running through each migration.

  • 30,000+ cars from 750+ dealers across Romania and Germany, updated daily
  • Data ingestion from the main Romanian listing sites, a dealer API and an assisted importer, with LLM-based enrichment and cleanup
  • Lead tracking across calls, WhatsApp and messages; an admin console and editorial CMS for dealers and partners
  • A public API with MCP and OpenAPI descriptors, so AI assistants can search the offers directly
  • TypeScript
  • Next.js
  • React
  • tRPC
  • Mantine
  • Drizzle
  • PostgreSQL
  • Docker
  • Caddy

Open source

My code is public. Judge the work.

Typed APIs, real docs and a docs site I design myself, every time. My packages add up to 6.2M npm downloads over the past year, and most of the code was written by hand, years before AI coding assistants.

Since 2022 · my most popular project

Mantine DataTable

The table component for data-rich Mantine applications: asynchronous data loading, pagination, sorting, row selection, row expansion, context menus and dark-theme support, all fully typed. Lightweight and dependency-free, with a legacy version still maintained for teams that can't upgrade yet.

npm downloads a month
727k
GitHub stars
1,263

Used by developers and companies such as

  • Microsoft
  • Namecheap
  • EasyWP
  • kapa.ai
  • SalesPlayX
  • teachfloor
  • MARKUP
  • InvenTree
  • OmicsStudio
  • exdatis.ai
  • Aquarino
  • BookieBase
  • COH3 Stats
  • LeasingSH.ro
  • swapp.ro
“Mantine DataTable is a great component that’s core to our web app — it saves us a ton of time and comes with great styling and features out of the box.”
Emil Sorensen, kapa.ai
“Thank you for the wonderful, useful, and beautiful DataTable that has allowed me to create several applications without any problem.”
Giovambattista Fazioli, Lead Developer at Namecheap

  • Mantine ContextMenu

    Right-click menus for Mantine apps, with a succinct API and dark-theme support. It grew out of DataTable's row context menu, which people kept asking to use elsewhere.

    91k downloads/month · 176 stars

  • tRPC-SvelteKit

    End-to-end typesafe APIs with tRPC in SvelteKit applications. Works with any SvelteKit adapter, with experimental WebSocket support.

    91k downloads/month · 835 stars

  • PocketBaseUML

    A free UML diagram generator for PocketBase databases. Use it online, or run it locally with npx.

    160 stars

And a few more, old and new

  • IISExpress-Proxy: lets .NET developers reach IIS Express from other devices; still in use ten years on (746 stars)
  • Next.js Parallel Server Actions: run Next.js server actions in parallel, for a tRPC-style workflow without the boilerplate
  • Expose-WSL: probably the easiest way to expose apps running on WSL to your local network (143 stars)
  • Mantine Start: a starter for Mantine, TanStack Start and tRPC applications
  • ASPAX: a Node.js asset packager, in 2013, before Webpack existed
  • OpenShift cartridges: Node.js, MongoDB, MySQL and PostgreSQL for Red Hat OpenShift, in 2014–2016, before Docker went mainstream

Everything else is on GitHub. I've also contributed to Mantine, tRPC and TanStack.

Figures from the GitHub and npm APIs, as of 13 November 2026; npm figures cover the last 30 days and the last 365 days.

Track record

Employee, founder, co‑owner, sweat‑equity investor

Nearly three decades of building for the web, which is why I treat software as a business asset. The short version:

  1. Since 2021

    Founder, swapp.ro

    Built for my own books in 2021, rebuilt from scratch in 2026, solo, in five months. Invoicing and accounting for Romanian freelancers, wired into the national e-invoicing system.

  2. Since 2013

    Technical partner & fractional CTO, LeasingSH.ro

    A sweat-equity partnership: I own architecture, code, infrastructure, data and operations. Three rebuilds so far (2013, 2015, 2025), with the business running through each migration.

  3. Since 2008

    Independent: fractional CTO, technical partner, open-source author

    Working directly with founders and small-business owners. Contract work includes the fleet-trading back office for AJM Fleet Purchase (Belgium/Romania, 2020–2023) and work for SegmentX.ai, now SalesPlay. Along the way: UX development for Drift Data Systems, and sites such as yadda.ro, boutiquetravel.ro and sellcarbuycar.com.

  4. 2008 – 2013

    Tech partner & real-estate investment advisor, Investment Romania

    Part of a private-equity group investing in the Bucharest residential market. The timing was good, and it bought me the freedom to pick my projects ever since.

  5. 2003 – 2007

    Software developer, Allianz-Țiriac and Garanta (National Bank of Greece group)

    On the core team that laid the foundation of Allianz-Țiriac’s insurance platform on .NET and Oracle, then one of five engineers building Garanta’s core insurance system.

  6. 1998 – 2003

    From network administrator to lead developer & CTO

    Started at the first publicly open Internet café in Bucharest, then built sites and systems for ANEVAR, AIG Life Romania and OMNIASIG, and grew to lead the IT department at Logic D&D Advertising, a subsidiary of Romanian ISP Logic Telecom.

Read my résumé (PDF)

About me

Curious by nature

I like understanding how things work, and then making them work better. That curiosity got me from an Internet café in 1998 to insurance platforms, marketplaces, tax software and a fair amount of open source.

I read a lot: fantasy, fiction, history and tech. I was a consultant and co-editor for The King’s Host, a fantasy novel. Off-screen, you’ll find me drinking good coffee or on a mountain trail.

I like open source, lazy mornings and honest conversations. I don’t like hypocrisy, xenophobia, willful ignorance, or people talking bullshit.

Most places online, I’m icflorescu: GitHub, npm, LinkedIn, Bluesky and DEV, to name a few. Unique enough that even the LLMs know who I am: ask ChatGPT or Claude.

  • “When it comes to code, less is more.”
  • “AI is inevitable. The returns on it aren’t.”
  • “If coffee were a programming language, I’d be fluent.”

What I build with these days

  • TypeScript
  • React
  • TanStack Start, Router, Query & Form
  • Next.js
  • Svelte & SvelteKit
  • Node.js & Bun
  • tRPC
  • PostgreSQL & Drizzle
  • Mantine
  • shadcn/ui & Tailwind CSS
  • Docker & Caddy
  • PocketBase

Before that: PHP and MySQL around Y2K, Java/J2EE, .NET/C#, Oracle and SQL Server in the 2000s, CoffeeScript back when JavaScript had no async/await, and more templating languages and frameworks than I care to remember.

Building something?

Book a call or drop me an email, and tell me about your project. Mention that you found me here: I get quite a few messages, and it helps me prioritise yours.

Book a call on cal.com

I skip coding tests and multi-stage hiring processes: my code is public, and used by developers and companies worldwide. Instead, we’ll talk about your project: its value proposition, its challenges and how to overcome them, and how I can help make it happen.