I build native products
for the Apple ecosystem.

Senior macOS & iOS Engineer · Endpoint Security · Product Craft

I architect reliable native applications for macOS and iOS,
and turn complex systems into intuitive, pixel-perfect experiences.Professional name: Viorel Porumbescu · Full name: Porumbescu Cornel Viorel

View selected work Download résumé

10+ years Swift / Objective-C AppKit / UIKit

Technologies and tools I work with.

Apple platforms

macOS · iOS · Swift · Objective-C · AppKit · UIKit · SwiftUI

Systems & security

Privileged services · XPC · Network Extensions · System Extensions · Endpoint security · NFC · Cryptography

Product engineering

Architecture · UI/UX design · REST APIs · Persistence · Real-time communications · Performance · Testing

Delivery & leadership

Technical direction · Mentoring · Code review · CI/CD · Signing & notarization · App Store release · Diagnostics

Experience

A track record of building reliable, native products and frameworks for Apple platforms.

Heimdal SecuritymacOS Developer & Team LeadAug 2021 — PresentRemoteBuilt a macOS endpoint-protection agent from the ground up, then grew into technical leadership for the team responsible for its architecture and delivery.Swift · Objective-C · AppKit · XPC · Network Extensions

Areas of ownership

Endpoint security architecture
Privileged macOS services
Network & system extensions
Native AppKit UI
Release engineering
Diagnostics & observability
Technical leadership

Designed the modular architecture of a production endpoint-security agent for macOS.
Built resilient background services, LaunchDaemons, privileged helpers, and XPC communication across process and privilege boundaries.
Implemented endpoint-protection and network-security flows with Network Extensions and System Extensions.
Delivered native AppKit interfaces and reusable custom components in Swift and Objective-C.
Designed secure local state and persistence using Keychain, SQLite, and defensive recovery paths.
Investigated production issues across performance, networking, and process boundaries with Instruments, structured diagnostics, and Sentry.
Owned release engineering: signing, notarization, installer packaging, CI/CD, upgrades, and non–App Store distribution.
Led technical direction, reviewed architectural decisions, set engineering standards, and mentored team members.

Company website

Tello / KeepCallingiOS DeveloperMar 2019 — Jul 2021Sibiu, RomaniaDeveloped and modernised a portfolio of international-calling and mobile-recharge apps serving more than 500,000 monthly active users.Swift · Objective-C · UIKit · Core Animation · Core Data

MingleBitmacOS/iOS Developer & UI/UX DesignerMay 2014 — PresentCraiova, RomaniaDesign, build, test, and publish native Apple utilities, owning both engineering and visual design across the complete product lifecycle.Swift · Objective-C · AppKit · UIKit · Core Graphics

University of Craiova · MANA Research LabResearch Lab MemberNov 2013 — Jan 2019Craiova, RomaniaCombined cryptography research with hands-on IT, networking, VoIP, web, and visual communication work in an academic environment.Cryptography · Elliptic Curves · Asterisk · FreePBX · Networking

Selected Apps & Frameworks

A collection of public work, private products, and independent Apple-platform apps.

QR Studio PRO— macOSIndependent product·Available on the Mac App StoreDesign branded QR codes, manage dynamic destinations, and understand scan performance in real time.

Product design · Native app · Service integration · Website · Release

QR Studio combines a visual QR designer, built-in scanner, multi-format export, dynamic links, and analytics in one focused native Mac product. A printed code can point somewhere new without being reprinted, while its dashboard turns scan activity into useful audience insight.

Key capabilities

Custom pixels, eyes, colours, backgrounds, corner radius, and embedded logos.
Screen, document, and webcam scanning.
PNG, JPEG, SVG, and PDF export at any resolution.
Dynamic-link management and real-time scan analytics.
A one-time purchase with no subscription.

Visit product site Mac App Store

QR Studio overview highlighting dynamic links, live analytics, custom styles, QR types, and the scanner

Product overview

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CEI One— iOSIndependent product · Private source·In developmentRead Romania’s electronic identity card over NFC and securely sign or validate PDF documents.

Product design · Native app · Cryptographic workflows · Privacy architecture · Website

CEI One turns complex electronic-identity workflows into clear native iPhone experiences. It reads supported identity data locally, prepares proof-of-address documents, signs PDFs with the certificate held on the card, and validates compatible electronic signatures.

Key capabilities

Secure NFC sessions authorised with the card’s CAN and PIN.
Cryptographic PDF signing with the private key remaining on the identity card.
Signature integrity, certificate-chain, timestamp, and revocation checks.
Document scanning, local history, optional iCloud sync, and Romanian/English localisation.
No account required; sensitive credentials are not synced.

Visit product site

CEI One home screen with electronic identity card, address proof, PDF signing, and document actions

Your ID, your data, your signature

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MeetingDetector— macOSPrivate prototype·Active prototypeDetect real Zoom, Microsoft Teams, and Google Meet sessions and open a compact live-transcript overlay.

Product concept · Architecture · Native app · Local transcription pipeline

MeetingDetector uses multiple semantic signals instead of merely checking whether a meeting app is open. It combines process, window, browser, and meeting-control context with hard-negative filtering and a debounced state machine, then transcribes locally and stores the resulting history on the Mac.

Key capabilities

Multi-signal meeting detection with permission-aware diagnostics.
Floating, always-on-top transcript panel.
Local Whisper-based transcription pipeline.
Local transcript storage and history.
Dedicated state-machine and view-model test suites.

Dynamic Wallpaper— macOSIndependent product·Available on the Mac App StoreBring time-based scenes to the desktop through curated high-resolution wallpapers and personal photo sets.

Product design · Native app · Catalogue experience · App Store release

Created for macOS Mojave’s native dynamic-wallpaper format, each scene combines photographs captured in the same place at different times so the desktop evolves naturally throughout the day. Users can also build their own dynamic sets from personal photographs.

Key capabilities

Time-based scenes that change throughout the day.
Carefully curated, high-resolution wallpaper collections.
Native support for macOS Mojave and later.
Tools for creating custom dynamic wallpapers from personal photos.

Visit product site Mac App Store

Wallpaper catalogue

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OnTime PRO— macOSIndependent product·Available on the Mac App StoreCombine customisable desktop clocks, alarms, world time, and smart break reminders in one focused tool.

Product design · Native app · Custom interface components · App Store release

OnTime PRO turns timekeeping into a flexible desktop workspace. Users can create unlimited clocks, personalise every visual element, build powerful alarms, follow locations around the world, and schedule intentional breaks without leaving the Mac.

Key capabilities

Analog, digital, fantasy, hybrid, and bent clock styles.
Custom colours, gradients, personal backgrounds, hands, and animations.
Live CPU, memory, and disk-usage indicators.
Unlimited alarms with custom sounds, voice messages, and progressive volume.
World clocks with sunrise, sunset, day/night themes, and time-difference calculation.
Configurable break schedules, focus-time exceptions, and quiet hours.

Visit product site Mac App Store

OnTime PRO overview with a collection of custom analog, digital, and system-monitoring clocks

Clock collection overview

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Open-source frameworks

Focused native components and Swift packages used by Apple-platform developers.

6 projects

MBIconsMore than 200 resolution-independent macOS icons drawn directly with NSBezierPath.530 ★MBCircularProgressA highly customisable macOS circular progress control with Interface Builder inspectable properties.40 ★MBPageControlA customisable native page indicator for macOS sliders and feature presentations.39 ★MBDoubleSliderA native macOS range-selection control originally designed for time intervals.30 ★MBToastMacA lightweight, customisable toast-notification library for native macOS apps.11 ★VPDownloaderA Swift 6 file-downloading package with cancellation, destination policies, retry strategies, and deterministic tests.1 ★

Education

2019 — 2021

Doctoral studies, Mathematics & Computer Science

University of Craiova

Research focused on nonlinear systems over nonsupersingular elliptic curves, elliptic-curve cryptography, and digital security.

2016 — 2018

Master’s degree, Advanced Techniques for Information Processing

University of Craiova

2013 — 2016

Bachelor’s degree, Computer Science

University of Craiova

Achievements

2019

2nd place

Advent of Code / Dolj

2018

4th place

Advent of Code / Dolj

2017

1st place

Mobile Coding Contest · Catalyst GmbH

2015

1st place

National Student Communications Session · University of Craiova

Contact

Let’s build something worth using.

My work spans endpoint security, networking, privileged macOS services, real-time communications, NFC, cryptography, document signing, and polished consumer utilities. I’m comfortable owning the complete product lifecycle: architecture, implementation, UI/UX, testing, CI/CD, signing, notarization, distribution, and long-term maintenance.

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LinkedInSend me a message

LocationSibiu, Romania

I build native productsfor the Apple ecosystem.

Apple platforms

Systems & security

Product engineering

Delivery & leadership

Open-source frameworks

Education, achievements and contact

Doctoral studies, Mathematics & Computer Science

Master’s degree, Advanced Techniques for Information Processing

Bachelor’s degree, Computer Science

Let’s build something worth using.

I build native products
for the Apple ecosystem.