Florian-Leonard Gozman

Hands-on CTO · Principal Backend Engineer & Architect

I still ship code, and some of it has been running in production for more than a decade. Twenty-five years building systems, the last twenty leading their design.

About

I started writing software in 2000 and never really stopped. Since 2004 I've been the hands-on CTO at GEBS, a software house in Cluj-Napoca, which in practice means I set the technical direction and still write the backend that sits underneath it: mostly Java and Kotlin on Spring, with MongoDB and AWS. What I care about most isn't any single launch. It's that several of the systems I designed years ago are still in daily use. Keeping something alive through a decade of real use turns out to be a different skill than getting it to demo well. I've shipped more than 25 business systems this way for clients across Europe and Asia, and the three below are the ones I like talking about.

My background is half engineering, half mathematics. I took a full maths degree alongside my engineering studies and spent two years as a research assistant in numerical and statistical calculus. That training still shows up in how I approach a system: I look for where the real constraints are, and whether a given abstraction is worth what it costs to maintain. AI has been an interest of mine for a long time. I've worked through Stanford and DeepLearning.AI courses on it, and I've put LLMs into production in the cases where they actually earned their keep.

Selected work

Three of the systems I've built. All of them are still in production, and each one taught me a lesson I keep using.

Zoniz

Architect & backend lead · in production since 2013

Zoniz began in 2013 as a beacon and proximity-engagement platform for municipalities, malls, expo centres and festivals, and later grew into a full restaurant product with QR menus, table ordering, online payments, a waiter app and kitchen displays. It powered the UNTOLD and Electric Castle festivals, ran Romania's first mall deployment with beacons (a EUR 1.5M proximity-marketing project at AFI Palace Cotroceni), and in a pilot at the District of Toast restaurant in Cluj-Napoca it doubled orders and revenue. More than 100 client projects have shipped on the platform.

I designed and built the backend: the core services, the payment, email and job-scheduling integrations, and the OpenAI content layer that generates and adapts product copy for clients.

The part I find interesting: the OpenAI layer is about as close as my work gets to "AI in production." It's integration, not model-building, but it's real. It runs against live client data, it has to fail gracefully when the model says something odd, and before it went in it had to prove it was worth more than a much simpler templated approach.
Core stack: Java, Spring, MongoDB, AWS, OpenAI, Beacons, Stripe, and more

Sosito

Architect & backend lead · in production since 2020

Paper timesheets are slow and easy to fake. With Sosito, employees clock in by tapping an NFC tag with their own phone: it keeps working offline, shows who is on site right now across multiple locations, and produces payroll and labour-inspectorate (ITM) reports in one click. It currently tracks more than 600 employees and over 5,000 clock-ins a month.

The backend services and the SMS and email notification flows are my work. The interesting constraint here was offline-first behaviour: a clock-in cannot be lost just because a phone has no signal in a basement or on a factory floor, so the system has to reconcile cleanly when connectivity returns.

What was actually hard: attendance software isn't difficult on the happy path. It's difficult because people have a reason to game it. The reports go to payroll and to government inspectors, so the data has to hold up to scrutiny. Most of the design effort went into making each record accurate and tamper-evident, not into adding features.
Core stack: Kotlin, Spring Boot, MongoDB, AWS, NFC, Twilio SMS, and more

CrossA

Architect & backend lead · in production since 2021 · EU-cofinanced R&D

CrossA is a configurable community-management platform for clusters, sports bodies, volunteer organizations, research centres and social associations. It handles hierarchical organizations, a drag-and-drop form builder, member subscriptions and payments, and was built as an EU-cofinanced research and development project.

I designed the data model and built the backend and the identity and single-sign-on layer. The challenge was generality without chaos: every client wants a slightly different structure, so the model had to be flexible enough to fit very different organizations while staying coherent enough to maintain and reason about.

Where it could have gone wrong: "highly customizable" is exactly where a lot of platforms quietly rot into spaghetti. Getting the configuration model right early, deciding what's allowed to flex and what stays fixed, is the thing that kept this one maintainable.
Core stack: Java, Spring Boot, MongoDB, AWS, Keycloak, and more
Earlier work A key part of IBM Rational Publishing Engine, used by IBM's largest customers; an environmental-law SaaS for Ragn-Sells (2,300 staff across six countries); and the Swedish Swimming Federation's central database, holding results for 100+ clubs and more than two million swims.

Beyond code

I like working where engineering meets the people who actually use the thing. Two decades of clients and teams across Sweden, Denmark, Hong Kong, Spain and the UK taught me that explaining a design well matters nearly as much as getting it right, and it took me a while to admit that. The best moment in the job is when a messy requirement turns out to have a clean structure hiding under it. Away from the screen I powerlift, which is what keeps the rest of it steady.

Maths + Engineering
Full mathematics degree taken alongside computer engineering
Doctoral research
Two years as a research assistant in Numerical & Statistical Calculus, Babeș-Bolyai University
Languages
Romanian (native), English (professional)