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Backend · Security · Infrastructure

Secure software,built to last.

Backends, REST and gRPC APIs, databases, security and the infrastructure they run on. Written plainly, tested at four levels, and delivered with the deployment, backups and monitoring included.

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Since 2014. Cluj-Napoca.

Four levels of testing
Unit, integration, functional and end-to-end, on every project. They run automatically on every change, against a real database rather than stubs that agree with whatever you assumed. That way, even when big changes go in, code does not reach production unless it is safe.
Built against anonymised data
I never develop or test against real data. I work from an anonymised copy of your database that keeps the shape and the volume of the real thing, with nothing in it that identifies a person. The anonymisation routine scrubs the backups too, so data cannot survive in an old restore point.
Role-based access control
Each role sees only what it is entitled to, and the rules are enforced everywhere. An administrator controls exactly what each kind of user may do, and can revoke access instantly when the need arises.
Backups every minute
Every minute for the last hour, hourly for the last day, daily for the last month, monthly for the last year, and yearly after that. Restores can be run on demand, and an agent verifies the integrity of the data every night.
Closed to the public internet
Only the load balancer has a public address. The application cluster and the database cluster hold private addresses only, with public traffic to them blocked outright. Administration happens over VPN, to keep the data safe.
Since 2014, across four sectors
Medical, entertainment, beauty and tech. Very different domains with the same underlying demands: correct data, controlled access, and a system that does not give out exactly when you need it most. I can build in any domain: creativity has no limits, and experience brings seniority and expertise.

What I do

From the first line of code to the server in production.

Four areas that hold each other up: the application, the data behind it, who is allowed to reach that data, and the machines it all runs on. I do all four, so you are never left holding code and having to find someone else to put it online.

  1. 001

    Backends and APIs

    The part that keeps the product alive: logins, orders, bookings, integrations and the day-to-day workflows. REST APIs for browser clients and gRPC between internal services, with contracts in protobuf, so a changed field breaks the build rather than production. I write plainly and on clear responsibilities first - KISS and SOLID - and then model the domain complexity on top of a solid foundation.

  2. 002

    Security and GDPR

    Role-based access through Keycloak, with authentication isolated in a separate layer the browser cannot go around. I hunt for vulnerabilities in dependencies and fix them before they matter, and passwords and keys live in a secrets manager rather than files left on a server. All development and testing runs against an anonymised copy of the database, and the anonymisation routine scrubs the backups too.

  3. 003

    Data and search

    Models that survive contact with reality and migrations that do not lose rows. I index against the queries that actually run, not the ones I expected at the start. Backups every minute for the last hour, hourly for the last day, daily for the last month, monthly for the last year and yearly after that - with restores available on demand and verified every night.

  4. 004

    Cloud and monitoring

    I handle the whole deployment. Only load-balancer systems hold a public address; the application cluster and the database cluster have private addresses only and public traffic to them is blocked, with administration over VPN alone. Both clusters run across several nodes, so if one goes down the application stays up on the others. The nodes sit in data centres in different countries, for extra redundancy.

Portfolio

Six examples in production from the portfolio.

Six of the projects running right now. The screens are captures from real deployments, not renders.

001

In production

OncoSurg

Private oncological surgery clinic, Cluj-Napoca.

Public site: found, then understood
Public site: found, then understoodThe clinic, the doctor and the phone number in the first screen. A presentation site has one job — turning a search into an appointment.
Seven languages, not just Romanian
Seven languages, not just RomanianRomanian, English, German, French, Italian, Spanish and Hungarian. An oncology clinic draws patients from across the region and the diaspora.
The internal application: today
The internal application: todaySame client, different product. Registered patients, consultations over the last 30 days and what is coming, with the team chat always within reach.
The practice calendar
The practice calendarMonth, week or day, with a filter across patient, doctor, title or note. Appointment types carry their own colours so the day reads at a glance.
A structured clinical record
A structured clinical recordDisease history, follow-ups, clinical and laboratory examinations, diagnoses and recommendations. Each entry is dated and edited in place.
Documents from templates
Documents from templatesMedical letter, certificate, observation sheet, informed consent. Templates filter per doctor, and the ones needing a signature are marked apart.
Chat per case, not per room
Chat per case, not per roomEvery conversation attaches to a patient or an operation, so the anaesthetist’s sign-off stays beside the case it belongs to.
Chat per case, not per room
Chat per case, not per room

Every conversation attaches to a patient or an operation, so the anaesthetist’s sign-off stays beside the case it belongs to.

Public site: found, then understood
Public site: found, then understood

The clinic, the doctor and the phone number in the first screen. A presentation site has one job — turning a search into an appointment.

Seven languages, not just Romanian
Seven languages, not just Romanian

Romanian, English, German, French, Italian, Spanish and Hungarian. An oncology clinic draws patients from across the region and the diaspora.

The internal application: today
The internal application: today

Same client, different product. Registered patients, consultations over the last 30 days and what is coming, with the team chat always within reach.

The practice calendar
The practice calendar

Month, week or day, with a filter across patient, doctor, title or note. Appointment types carry their own colours so the day reads at a glance.

A structured clinical record
A structured clinical record

Disease history, follow-ups, clinical and laboratory examinations, diagnoses and recommendations. Each entry is dated and edited in place.

Documents from templates
Documents from templates

Medical letter, certificate, observation sheet, informed consent. Templates filter per doctor, and the ones needing a signature are marked apart.

Chat per case, not per room
Chat per case, not per room

Every conversation attaches to a patient or an operation, so the anaesthetist’s sign-off stays beside the case it belongs to.

Public site: found, then understood
Public site: found, then understood

The clinic, the doctor and the phone number in the first screen. A presentation site has one job — turning a search into an appointment.

Two products for the same client: the public site, in seven languages, that gets the clinic found, and the internal application the day is actually run from — patients, calendar, clinical records, signed documents and messaging between doctors. The browser never talks to the API directly; between them sits a layer holding the session and the token. Every change passes nine automated stages before production.

View the projectVisit the site
Outcome
In production at a private oncological surgery clinic in Cluj-Napoca, with a public site in seven languages and an internal practice application.
Built with
GoReact 19PostgreSQL 16Kubernetesi18n · 7 limbiPDFChat

002

In beta

Remedic

A medical platform in three flavours: Cabinet, Dental and Pet.

The day, in numbers
The day, in numbersAppointments today, confirmed, completed and pending, with the shape of the week and the split by appointment type.
The Grafit theme
The Grafit themeSame application, different theme. Three ship — Luminos, Navy and Grafit — and the choice belongs to the doctor, not to me.
A consultation is signed
A consultation is signedHistory, examination and treatment plan, filled in by section and closed with a signature. Shown here in the Navy theme.
Tools beside the record
Tools beside the recordICD-10, medicines with interaction checking, clinical scores, a DRG calculator and protocols — all opening without leaving the consultation.
Messaging the patient
Messaging the patientSecure communication attached to the patient’s file. A reschedule takes two messages instead of four phone calls.
Stock with expiry dates
Stock with expiry datesConsumables tracked by quantity and expiry, with low stock flagged before it becomes a problem.
You build the form
You build the formConsultation sections reorder, switch on and get added from settings. Saving creates a new version, and old consultations stay untouched.
You build the form
You build the form

Consultation sections reorder, switch on and get added from settings. Saving creates a new version, and old consultations stay untouched.

The day, in numbers
The day, in numbers

Appointments today, confirmed, completed and pending, with the shape of the week and the split by appointment type.

The Grafit theme
The Grafit theme

Same application, different theme. Three ship — Luminos, Navy and Grafit — and the choice belongs to the doctor, not to me.

A consultation is signed
A consultation is signed

History, examination and treatment plan, filled in by section and closed with a signature. Shown here in the Navy theme.

Tools beside the record
Tools beside the record

ICD-10, medicines with interaction checking, clinical scores, a DRG calculator and protocols — all opening without leaving the consultation.

Messaging the patient
Messaging the patient

Secure communication attached to the patient’s file. A reschedule takes two messages instead of four phone calls.

Stock with expiry dates
Stock with expiry dates

Consumables tracked by quantity and expiry, with low stock flagged before it becomes a problem.

You build the form
You build the form

Consultation sections reorder, switch on and get added from settings. Saving creates a new version, and old consultations stay untouched.

The day, in numbers
The day, in numbers

Appointments today, confirmed, completed and pending, with the shape of the week and the split by appointment type.

A medical platform built as separate services talking over gRPC against protobuf contracts. Authentication goes through Keycloak with PKCE and the tokens stay on the server. The doctor builds their own consultation form, picks one of three themes, and messages patients securely. Three flavours on one core — Cabinet, Dental and Pet — with Cabinet available now, free for residents.

View the projectVisit the site
Outcome
The Cabinet flavour is in clinical beta with a Romanian practice, ahead of general release.
Built with
GogRPCprotobufKeycloakReact 19PostgreSQLICD-10DRG

003

In production

Salon-Manager

Bookings, stock, documents and money for beauty salons.

A column per technician
A column per technicianThe salon’s day, a colour for each specialist. It also reads by month or week, filtered by who is working.
Every appointment, with its status
Every appointment, with its statusScheduled, confirmed or completed, filtered by range. The dark theme is one of the three that ship.
Complete and charge
Complete and chargeServices with their prices, the estimated total, the client’s other appointments, and one button that closes the booking and records the payment.
Profit and loss, not just takings
Profit and loss, not just takingsRevenue, discounts, tips, commissions, product cost and net. Broken down by payment method and by technician, each with their own commission rate.
The salon writes the messages
The salon writes the messagesA template with self-filling fields, a preview against real data, and as many send rules as needed: a day before, an hour before, at a fixed time.
The salon picks the look
The salon picks the lookTheme, ten accent colours, density, glass strength, text size, and the colour of the status bar on the phone.
GDPR consent in plain view
GDPR consent in plain viewSet out in full inside the client file, with its status — signed or unsigned — and the verified WhatsApp number beside it.
The same app, on a phone
The same app, on a phoneA native mobile app with bottom tabs and the day’s calendar. A salon is not run from a desk.
The same app, on a phone
The same app, on a phone

A native mobile app with bottom tabs and the day’s calendar. A salon is not run from a desk.

A column per technician
A column per technician

The salon’s day, a colour for each specialist. It also reads by month or week, filtered by who is working.

Every appointment, with its status
Every appointment, with its status

Scheduled, confirmed or completed, filtered by range. The dark theme is one of the three that ship.

Complete and charge
Complete and charge

Services with their prices, the estimated total, the client’s other appointments, and one button that closes the booking and records the payment.

Profit and loss, not just takings
Profit and loss, not just takings

Revenue, discounts, tips, commissions, product cost and net. Broken down by payment method and by technician, each with their own commission rate.

The salon writes the messages
The salon writes the messages

A template with self-filling fields, a preview against real data, and as many send rules as needed: a day before, an hour before, at a fixed time.

The salon picks the look
The salon picks the look

Theme, ten accent colours, density, glass strength, text size, and the colour of the status bar on the phone.

GDPR consent in plain view
GDPR consent in plain view

Set out in full inside the client file, with its status — signed or unsigned — and the verified WhatsApp number beside it.

The same app, on a phone
The same app, on a phone

A native mobile app with bottom tabs and the day’s calendar. A salon is not run from a desk.

A column per technician
A column per technician

The salon’s day, a colour for each specialist. It also reads by month or week, filtered by who is working.

SaaS for salons where each salon is a fully isolated tenant in the database. It carries a per-technician calendar, client files with signed GDPR consent, a profit-and-loss report with per-technician commission, WhatsApp reminders with the salon’s own templates and reply-to-confirm, a native mobile app, and an appearance page where the salon sets its own theme, accent colour and interface density. Mani-Manager, live at mani-manager.ro, is the personalised instance.

View the projectVisit the site
Outcome
In production at two salons through the Mani-Manager instance, with online booking, WhatsApp reminders, financial reports and a mobile app.
Built with
GoReact 19PostgreSQLWhatsAppPDFMobileMulti-tenant

004

In production

Eventum

Invite-only seat booking for charitable events.

The platform, for organisers
The platform, for organisersThe platform’s own public site: what it does, how it works and who uses it. The way in for event organisers.
The event carries its own brand
The event carries its own brandThe club’s logo in place of the platform’s, its own navigation, and a cause page explaining the beneficiary and the share that reaches them.
An editor with live preview
An editor with live previewThe page on the left, the structure on the right. Sections, repeatable blocks dragged into order, and images from a library — the organiser writes their own evening.
The admin panel
The admin panelPublished events and drafts, halls and analytics, with the next events and each beneficiary in plain view.
From invitation to donation
From invitation to donationPledged against collected, occupancy and pledge rate, with a funnel that shows exactly where people drop out.
From invitation to donation
From invitation to donation

Pledged against collected, occupancy and pledge rate, with a funnel that shows exactly where people drop out.

The platform, for organisers
The platform, for organisers

The platform’s own public site: what it does, how it works and who uses it. The way in for event organisers.

The event carries its own brand
The event carries its own brand

The club’s logo in place of the platform’s, its own navigation, and a cause page explaining the beneficiary and the share that reaches them.

An editor with live preview
An editor with live preview

The page on the left, the structure on the right. Sections, repeatable blocks dragged into order, and images from a library — the organiser writes their own evening.

The admin panel
The admin panel

Published events and drafts, halls and analytics, with the next events and each beneficiary in plain view.

From invitation to donation
From invitation to donation

Pledged against collected, occupancy and pledge rate, with a funnel that shows exactly where people drop out.

The platform, for organisers
The platform, for organisers

The platform’s own public site: what it does, how it works and who uses it. The way in for event organisers.

A booking engine for charitable events where every guest gets a personal link. Each event gets its own micro-site carrying the organiser’s logo and colours, edited from a panel with live preview. The analytics follow the road from invitation to donation and show what was pledged against what was actually collected.

View the projectVisit the site
Outcome
In production for a series of charitable events, with one concert delivered and more scheduled.
Built with
GoReact 19PostgreSQLWhatsAppSMTPCMSAnalytics

005

In production

Get Home Safe

A private ride home from events outside the city.

A name and a number
A name and a numberNo account and no password. The consent line says exactly who uses the number, for how long, and that it does not reach third parties.
Stops, service, cars
Stops, service, carsSeveral destinations in the order you want, and a choice between a normal ride and “drive me safe”, where two drivers bring home both guest and car.
The ride, step by step
The ride, step by stepSent, taken, driver on the way, arrived, heading home — with the registration plate, the estimate, and a button that calls directly.
The organiser’s panel
The organiser’s panelHow many drivers are free right now, the roster filtered by state, WhatsApp one click away, and assignment of incoming requests.
History with the price broken out
History with the price broken outThe route on a map, the rating received, and the final price: billed kilometres, per-kilometre rate, waiting time, and who pays.
The driver’s app
The driver’s appNative Android, for background location and notifications that sound with the phone in a pocket. State, current ride, and available orders with their prices.
The driver’s app
The driver’s app

Native Android, for background location and notifications that sound with the phone in a pocket. State, current ride, and available orders with their prices.

A name and a number
A name and a number

No account and no password. The consent line says exactly who uses the number, for how long, and that it does not reach third parties.

Stops, service, cars
Stops, service, cars

Several destinations in the order you want, and a choice between a normal ride and “drive me safe”, where two drivers bring home both guest and car.

The ride, step by step
The ride, step by step

Sent, taken, driver on the way, arrived, heading home — with the registration plate, the estimate, and a button that calls directly.

The organiser’s panel
The organiser’s panel

How many drivers are free right now, the roster filtered by state, WhatsApp one click away, and assignment of incoming requests.

History with the price broken out
History with the price broken out

The route on a map, the rating received, and the final price: billed kilometres, per-kilometre rate, waiting time, and who pays.

The driver’s app
The driver’s app

Native Android, for background location and notifications that sound with the phone in a pocket. State, current ride, and available orders with their prices.

A name and a number
A name and a number

No account and no password. The consent line says exactly who uses the number, for how long, and that it does not reach third parties.

Guests scan a QR code and ask for a car home: no account, no password, nothing to install. The request reaches every free driver and the first to take it keeps it. Drivers get a native Android app, and the organiser gets a live panel with the roster, assignment, and a history where each ride shows its price broken down by distance and waiting time.

View the projectVisit the site
Outcome
Running at Micus Barn and one further venue, with four events delivered and more scheduled.
Built with
GoPostgreSQLWebSocketsReactFlutterOSMKubernetes

006

In production

FriendlyDent

Public site for a dental clinic in Florești, Cluj.

Found, then phoned
Found, then phonedTwo phone numbers in the top bar, on every screen. A clinic site has one job and should not complicate it.
Services, in plain words
Services, in plain wordsEach treatment in the patient’s own words, saying explicitly where national insurance covers it and up to what limit.
Tariffs filtered by category
Tariffs filtered by categoryTap a category and see only its prices. The most visited page on a clinic site deserves to be the fastest.
Cases and gallery
Cases and galleryReal results, uploaded by the clinic from its own panel, without ringing a developer for every photograph.
Cases and gallery
Cases and gallery

Real results, uploaded by the clinic from its own panel, without ringing a developer for every photograph.

Found, then phoned
Found, then phoned

Two phone numbers in the top bar, on every screen. A clinic site has one job and should not complicate it.

Services, in plain words
Services, in plain words

Each treatment in the patient’s own words, saying explicitly where national insurance covers it and up to what limit.

Tariffs filtered by category
Tariffs filtered by category

Tap a category and see only its prices. The most visited page on a clinic site deserves to be the fastest.

Cases and gallery
Cases and gallery

Real results, uploaded by the clinic from its own panel, without ringing a developer for every photograph.

Found, then phoned
Found, then phoned

Two phone numbers in the top bar, on every screen. A clinic site has one job and should not complicate it.

A static site for a dental clinic: services explained in the patient’s own words, tariffs filtered by category, and a short path to booking. No internal application, no account, no login — a presentation site has one job, and here it is done quickly.

View the projectVisit the site
Outcome
In production at friendlydent.ro as the clinic’s main site.
Built with
Next.jsTypeScriptTailwind CSSSEO

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