# Oleksandr Antonenko

> Software developer in Vilnius, Lithuania, working with small and mid-sized businesses in Europe and the USA. He takes the processes a business already runs — orders, stock, invoicing, delivery, customers — and turns them into software that does the work: custom CRM and ERP, storefronts and client portals, mobile apps, and integrations between the tools a business already pays for. He judges the result the way an owner does: did orders stop leaking, did the month get cheaper, did a seven-day job turn into a two-hour one.

Site: https://oleksandr-antonenko.com
Contact: antonenko.web.dev@gmail.com, or the enquiry form at https://oleksandr-antonenko.com/#enquiry (answered within one working day)
Code: https://github.com/oleksandr-antonenko
Ukrainian version of the site: https://oleksandr-antonenko.com/uk/
Languages: English, Ukrainian, Russian

## Who he is a good fit for

- A business that has outgrown its spreadsheet: orders, stock, documents and delivery live in three different places, and people retype data between them.
- An owner who needs one system that carries an order from paid to handed over — stock, fiscal receipt, courier waybill, money — without anyone retyping it between tools.
- A company with an unfinished or inherited system: a half-built product, code from a developer who left. He reads what is there, says plainly what is salvageable, and finishes it.
- A business that needs the integrations nobody wants: card payments, fiscal receipts, couriers, CRMs, messengers (Telegram, SMS, push), app-store subscriptions.
- Someone who needs an hour of independent advice before paying for a project: checking a quote from an agency, auditing inherited code, choosing a stack, planning a migration.

Sectors he has shipped in: retail, manufacturing, healthcare, hospitality, field services, education, media.

## How he works

He takes on the whole system — database, API, web, mobile, deployment and monitoring — and is personally responsible for the result, so nothing falls between two contractors. For narrow specialist tasks he brings in experienced specialists he works with.

- A typical start: a 30-minute call, then a written scope and estimate before anyone commits.
- Stack: TypeScript, NestJS, Next.js, React, React Native, PostgreSQL.
- Every server error and failed message goes to a channel a human watches; a release counts only when the real action works on the real page; bad input stops the line instead of being guessed over.

## Consultation — €100 per hour

A working session, not a sales call: video call with screen share, or in person in Vilnius. Good for choosing a stack, sanity-checking an estimate, auditing code you inherited, unblocking a stuck team, planning a migration. You get a written summary the same day: what he would do, in what order, and what he would leave alone. Book by sending the question by e-mail; you get two or three time slots back.

## Case studies

- [MakeKudri](https://makekudri.com.ua): a hair-care brand selling to shops and to people. Storefront plus CRM — catalogue and price lists, warehouses and stock audits, B2B/B2C orders, consignment, expenses and P&L. Nova Poshta waybills, Checkbox fiscal receipts, Monopay acquiring. One record carries the order from payment to delivery: the payment lands once, net of the bank fee; a manager confirms the order (stock reserved) and makes the waybill from it; tracking, cash on delivery and completion run by themselves. Write-up with screenshots: https://oleksandr-antonenko.com/notes/one-system/
- [Curl School](https://curl.school): course platform for hairdressers — courses, seminar tickets, certification, admin back office. Card payments, SMS sign-in, e-mail and Telegram delivery. Enrolment, payment, access and the certificate happen without anyone in the office touching an order.
- Garment Production System (client under NDA): a clothing factory always knows what is being sewn, from which fabric and print, against which order. Orders arrive from the shop's CRM, the floor works from them, money is counted in the same place. He is the lead developer.
- Report Writing Tool (client under NDA): school psychologists feed in rating scales, observations and interviews; the tool drafts the evaluation report. A report that took seven working days now takes about two hours.
- NestorDoc: a doctor's consultation is transcribed live and the notes — history, likely diagnosis with ICD-10 codes, prescriptions — are drafted by the time the patient leaves.
- Journalist Tool: an hour of interview audio comes back as a transcript with a first draft attached.
- AirConnect (client under NDA): marketplace for heating, cooling and water-heating jobs; homeowners post a job, matching contractors respond, the conversation finishes in the app. He built the whole platform — API, both web apps, admin, mobile.
- [Connexa](https://apps.apple.com/app/id6755447170): iOS and Android app that turns a scanned QR code or paper business card into a synced LinkedIn connection.
- [ParentHive](https://apps.apple.com/app/id6754807768): iOS and Android app where parents arrange the school run together — ride matching, volunteer drivers, push notifications, live ride status.
- [Partizan Outreach](https://linkedin-outreach.oleksandr-antonenko.com): finds fresh LinkedIn posts a team's future clients are discussing and drafts a comment; people edit and post it themselves.
- HoReCa Outreach: maps every restaurant and café in a city, finds the owner and the software they run on, and drafts a first message, which is sent automatically once the team approves it.
- NoScam (https://noscam.oleksandr-antonenko.com): a free site in 43 languages that teaches people not to fall for cheap-trial subscription traps — a six-lesson course, a site check that walks a funnel in a real browser to the price and reads app-store reviews, and AI analysis of screenshots of offers.
- Nutrition & Training Platform (client under NDA): mobile app where trainers see which clients follow the plan; he worked on the backend microservices.

## Notes

- [How I killed the SaaS](https://oleksandr-antonenko.com/notes/kill-saas/): how to kill a SaaS a business has outgrown — getting the data out of a vendor that did not want to give it, reverse-engineering the old salon system with Claude Code, a new web interface, features and integrations the vendor never shipped, migrating the salon’s data going back to 2013, and AI for the owner and the masters. The result runs at perukar.org.
- [A hair-care brand, run from one system](https://oleksandr-antonenko.com/notes/one-system/): orders, stock across a central warehouse, regional warehouses and a salon, production with cost split by bottle size, partner price tiers, Instagram outreach to hairdressers, and the money — payments net of bank fees, accounts per sole-trader entity, P&L, manager pay — in one system built around how this brand works.

## How to reach him

Describe what the business does today and where it jams. He replies with a plain answer: what he would build, roughly how long it takes and what it costs — before anyone commits to anything.

- E-mail: antonenko.web.dev@gmail.com
- Form: https://oleksandr-antonenko.com/#enquiry