Let’s talk

Available for new projects

Apps and web products, built to ship.

I’m Valentyn Khutornenko — a freelance software engineer with nine years in iOS, Android and the web. I take products from the first sketch to the App Store: on my own, or with a small, trusted team I lead.

Start a project See selected work
  • Thessaloniki, Greece
  • Clients across Europe & the US
  • Replies within a day
Valentyn Khutornenko --:-- in Thessaloniki
Valentyn KhutornenkoSoftware engineer · freelance Swift · Kotlin · TS
Shipping apps since
2017
Companies & startups worked with
20+
Engineers in the teams I lead
up to 6
Longest client partnership
4 yrs

Selected work

Products I’ve built

Telemedicine, messaging, live video, connected hardware, travel and the web — a few highlights from nine years of shipping.

HealthcareiOS · Android

Neoteric Health

Telemedicine platform for doctors and patients in the US: secure chats, audio and video calls, multi-party consultations.

  • Swift
  • Kotlin
  • Twilio
  • SendBird
  • CallKit

MessagingiOS

Pinngle Messenger

Messenger with group audio and video calls. Built public channels and conference calls, and moved a large Objective‑C codebase to Swift.

  • Swift
  • Objective‑C
  • C++
  • CallKit
  • VoIP

Live videoiOS

GlobalM

Live streaming platform: broadcasting and HLS playback on iOS, with a native media pipeline in C++ and GStreamer.

  • Swift
  • C++
  • GStreamer
  • HLS
  • AVFoundation

Connected fitnessiOS

Hyfit & Olympus Grips

Fitness apps paired with custom Bluetooth LE hardware: device pairing, real-time sensor data, training programs and progress charts.

  • Swift
  • CoreBluetooth
  • Charts
  • Firebase

TraveliOS

RVBooking

Campsite booking for RV travellers: map search, reservations, Apple Wallet passes and deep links into every stay.

  • Swift
  • MapKit
  • Wallet
  • Deep links

Web studio2026

nomoly.

My own studio for small businesses in Greece: fast multilingual websites, live in five days, plus ads and Google profiles.

  • Static web
  • Cloudflare Workers
  • D1
  • 4 languages

Also shipped: IMAX cinema app · Relaxo meditation · KekFeed · Fixar marketplace · Nardan Bazaar · Niko Barbershop — and internal tools under NDA.

Services

What I can do for you

One engineer who covers the whole product — and a trusted team behind him when the scope grows.

Mobile apps

Native iOS in Swift and SwiftUI, Android in Kotlin, or cross-platform with React Native — from MVP to an App Store-ready release.

Web products

Fast sites, dashboards and platforms with React, Next.js, Astro and Node.js — deployed on Cloudflare or AWS.

Real-time & devices

Audio and video calls, chat, live streaming and Bluetooth LE hardware — the hard parts most teams avoid.

AI features

LLM-powered features, agents and automations with OpenAI and Claude — wired into real products, not demos.

Team & tech lead

Architecture, code review and a vetted team of iOS, Android and DevOps engineers when one person isn’t enough.

Rescue & modernise

Objective‑C to Swift migrations, crash and performance fixes, CI/CD with Fastlane and Bitrise — for apps that need a second life.

About

From marine engines to mobile apps

I trained as a marine engineer and wrote my first production code for ship engine automation, in C and C++. In 2017 I switched to iOS — and haven’t stopped shipping since.

Since 2019 I’ve worked independently, as a private entrepreneur, with startups, agencies and established companies. Some projects I build alone; for bigger ones I lead a small distributed team of engineers I’ve worked with for years.

I care about the boring things that make products last: clear scope, weekly demos, honest estimates, and code the next developer will thank you for.

  1. Engineering roots

    Marine engine automation in C/C++; bachelor’s in marine engineering, Azov Maritime Institute.

  2. First apps in the App Store

    Apps for a supermarket, a barbershop, taxi and food delivery — built from scratch in Swift.

  3. Real-time at scale

    Pinngle Messenger: group calls, public channels, Objective‑C to Swift, code review.

  4. Independent

    Went freelance. First up: iOS and Android for Neoteric Health, a US telemedicine platform. Since then, 20+ companies across Europe and the US.

  5. Leading teams

    Running distributed teams of iOS, Android and DevOps engineers for long-term clients.

  6. nomoly.

    Launched a web studio for small businesses in Greece.

Stack

Tools I trust

Picked per project, not per habit. Native when it matters, cross-platform when it pays off.

Mobile

  • Swift
  • SwiftUI
  • UIKit
  • Objective‑C
  • Kotlin
  • React Native

Web

  • TypeScript
  • React
  • Next.js
  • Astro
  • Node.js
  • Express

Data & cloud

  • PostgreSQL
  • Firebase
  • Cloudflare
  • AWS
  • Realm
  • SQLite

Real-time & hardware

  • WebRTC
  • Twilio
  • SendBird
  • CallKit
  • HLS
  • CoreBluetooth

Delivery

  • Fastlane
  • Bitrise
  • CircleCI
  • App Store Connect
  • Google Play

AI

  • OpenAI
  • Claude
  • Agents & tool use

Process

How we’d work together

  1. 01

    Intro call

    30 minutes, free. Goals, constraints, timeline — and whether I’m the right fit.

  2. 02

    Plan & estimate

    A written scope with a fixed price or a monthly rate. No surprises later.

  3. 03

    Build

    Weekly demos and builds you can install from week one — TestFlight or staging.

  4. 04

    Launch & support

    Store submission, monitoring and a support window after release.

Contact

Have a product in mind?

Tell me what you’re building and where you’re stuck. I’ll reply within a day with questions, a rough plan and an honest estimate.

hello@valiok.com
  • Within a dayTypical reply time
  • --:-- · ThessalonikiGreece, EET / EEST
  • EUR or USDInvoices as a private entrepreneur, contracts in English