Tallinn, Estonia · Founder of Drezon Technologies

Andrei Sazonov

I build software that runs real businesses. My system runs the daily work of Olde Hansa, a 300-seat restaurant in Tallinn's Old Town: online bookings, prepayments, the kitchen board and the team's tasks. When it's needed, I also wire the network and fix the hardware it runs on.

See the work Try the Haldus demo ↗ Contact Haldus product site

300 seats3 floors running on Haldus every day

2–3 h → 30 minmorning planning time at Olde Hansa

4 languageson the Shoppe.ee web shop

Selected work

In production

Haldus at Olde Hansa

One system for a restaurant's whole day: reservations with pre-orders, prepayments and pay-separately links, a portal for travel agencies, the kitchen board with allergies, the daily report against POS data, and the team's tickets and meetings. I built it inside the house while it kept running.

Planning the day used to take 2–3 hours every morning. With Haldus it takes 30 minutes.

Node.jsExpressSQLite → PostgreSQLReactStripeMontonioCompuCash POSCaddy · Linux VPS

Try the Haldus demo ↗ Product site ↗ Live booking form ↗ oldehansa.ee ↗

Olde Hansa restaurant at dusk on Vana turg, with the Town Hall tower behind — Olde Hansa, Tallinn Old Town

Haldus day plan: guests seated per floor through one evening, peaking at 170 at 19:00 — Haldus day plan: guests per floor through one evening. Demo data, guest names removed. Click to see the full screen.

In use at Olde Hansa

ACQ payments

The payment layer under Haldus. Guests prepay their booking online, by card through Stripe or by bank link through Montonio, and the payment confirms the booking on its own. For big parties, one QR code lets every guest pay their own share from their phone while the organiser watches who has paid.

Stripe handles cards for international guests. Montonio handles local bank links. Every payment is matched to its booking, so the accountant sees which money belongs to which invoice.

StripeMontonioQR split paymentPrepaymentWebhooksNode.js

acq.ee ↗

Pay-your-share page on a phone: Joyful Christmas Feast, 68 euros, paid 0 of 11 — Pay-your-share page on a phone. Demo booking.

Try it: split a feast· sample party, no money moves

Guests 10

Each guest pays

Next guest pays with

One code for the whole table. Guests scan and pay their own share. Sample code, opens acq.ee.

Paid so far

€00 of 10 guests

Guests

Live

Shoppe.ee

The web shop of Olde Hansa: hand-blown glass, pottery, spices, schnaps and books. It runs on a headless CMS I built. The shop speaks English, Estonian, Finnish and Russian, sells curated "scenes" as a set, handles gift cards and applies the right VAT rate per product type.

Headless CMS4 languagesGift cardsPer-product VAT

Visit shoppe.ee ↗

shoppe.ee home page with three curated scenes and their products — shoppe.ee home page: scenes sold as a set

shoppe.ee product page for the Wein König glass, 105 euros including VAT — Product page with the VAT rate per product

Hardware

Software in a restaurant only works if the network, terminals and devices under it do. I take care of that layer too.

Bench

Phone repair

I repair Android phones and iPhones in a separate room set up for electronics work: screen and battery replacements, diagnostics and soldering.

Phone on a desk with a cracked display, still lit — In: cracked display

Opened iPhone on a repair mat: battery, Taptic Engine and logic board — Opened up on the mat

Phone with a new display fitted, next to a clamp on the bench — New display fitted

Infrastructure

Venue network & POS

A restaurant floor on a 1 Gbps house network, with POS terminals on the internal network. I added four wifi access points and track down intermittent POS dropouts through the switches and cabling.

Education

2026 –

Tallinn University of Technology (TalTech)BSc Business Information Technology. Information systems, software architecture and the business side of IT.

2025 – 2026

University of TartuHardware Engineering

Before

Gustav Adolf Grammar SchoolEngineering track. Student Council President and led a student company.

Awards

Tallinn Student of the Year 2025Also named Tallinn Volunteer of the Year.

What I bring to a 72-hour team

I ship end to end

Interface, API, database, payments and deployment on a Linux server. Haldus is all of these in production.

I build fast with AI

I write production software with Claude Code every day, and I know where to check its work.

I know real domains

Hospitality operations and payments, from the inside of a working restaurant.

I can handle the hardware

If the demo needs a device, a terminal or a network, I can wire and debug it.

Contact

E-mail: info@drezon.ee
Phone: +372 5691 0007 · WhatsApp
Company: Drezon Technologies OÜ · Haldus