Данило

General
Name: Danylo Horielov
Position: Mobile Developer, iOS (SwiftUI) and Flutter
Location: Kharkiv, Ukraine
Education: Software Engineering / Computer Engineering. Kharkiv National
University of Radio Electronics, 2019-2025.

Tags
iOS, Swift, SwiftUI, SwiftData, CoreData, Dart, Flutter, BLoC, Provider, Dio, HIVE,
Isar, Realm, sq ite, DDD, SOLID, DRY, KISS, Plugins, Firebase, Firestore,
Crashlytics, BLE, OTA, Medical, Revanue Cat, HIPAA, OpenAI, ChatGPT, Android
Studio, Xcode, CI/CD, Git.

Summary
Delivering production-level apps across healthcare, audio tech, pet tracking, and
accessibility. Experienced in both client-server architectures and device
integrations, such as Bluetooth and OTA updates. Skilled in SwiftUI, Flutter, and
native integrations for Flutter apps. Pro cient in designing exible architectures
that minimize future changes and ensure seamless scalability. Frequent
collaborator with clients to re ne vague requirements, identify edge cases, and
propose more e cient or scalable solutions. Comfortable working across the full
app lifecycle — from architecture and prototyping to deployment and post-launch
support.

Personal Projects
Vzhytok — Ukrainian vocabulary Flutter app (9к+ lines of code). Designed and
implemented a exible word entry system, including a custom stress-marking
mechanism (initially complex, later optimized). Added a training mode for
practicing word recall and built a robust word storage and migration system to
support long-term usage and updates.

Counter: History & Widgets — A Flutter app for tracking counters with historical
changes (11к+ lines of code). Designed for both mobile and tablet form factors
with adaptive UI. Included customizations for UI elements and themes, along with
support for iOS and Android home screen widgets. When interactive widgets were
released, added full support for quick actions directly from the home screen. The
app have 1к+ MAU.

Work Experience. ABCloudz. Feb 2022 - Present
iOS Projects (SwiftUI)
AltBionics — An application for con guring and controlling a prosthetic hand.
Took over development when the project had ~6к lines of code and expanded it to
12к+ lines, contributing signi cantly to its evolution and feature development.
Implemented a Developer Mode to unlock advanced capabilities used during
fl
fl
ffi
fi
fi
fi
fi
fl
 factory calibration, allowing technicians to adjust the default hand con guration
before shipping. Optimized the user ow for grip creation by automating actions,
such as triggering grip simulations upon slider adjustments or tab switches.
Integrated various features, ranging from simple tasks like turning on the ashlight
and changing its color to more complex functionalities, such as enabling test
modes with sub-settings for hand testing and collecting testing statistics.
Frequently worked without formal requirements or designs, translating and
optimizing client ideas into technical solutions, while also proposing alternative
approaches to better meet project goals. Additionally, integrated OTA update
functionality, including rmware parsing, update validation, and execution
according to rmware documentation.

Keyssistant — Developed a custom iOS keyboard with an additional panel for
generating and inserting AI-powered text suggestions. Users could select a
response type, trigger content generation, preview multiple results in place of
typed characters, and insert the preferred suggestion. Focused on creating an
intuitive UI and smooth UX within the system keyboard constraints. The app was
later published under the company’s account.

Dusker — Independently developed an audio management application supporting
a range of connected audio devices, contributing approximately 80%+ of the 10к+
lines of Swift codebase. Designed a scalable, protocol-oriented architecture to
enable seamless integration of new devices and audio libraries. Built a modular
system for managing sound libraries with adaptive data sources, including a
gallery of sounds and guided exercises. Implemented initial support for local
storage with a planned migration to Firebase. The app also functioned as an
equalizer for ne-tuned audio control. Later onboarded another developer to help
speed up feature development and contributed to ongoing platform growth.

Speechnnotes — A compact three-screen app for audio/video upload and
automatic transcription. My contributions included improving the upload ow,
xing several bugs, and adding portrait-mode support.

Men’s App (Spur Fitness App) — Joined an existing Vibe-codebase to stabilize
and extend functionality. Implemented AI-powered recipe generation to replace
hardcoded content, enabling dynamic creation of Recipe models from scratch,
text, images, and links. Integrated Firebase for data persistence, and added
browser and share extensions for importing recipes from external sources.
Implemented a barcode scanner and integrated it with the Open Food Facts API.

Listen for Therapist — Developed key features of a HIPAA-compliant application
for psychotherapists, enabling users to record, upload, and analyze audio sessions
with detailed reporting capabilities. Contributed approximately half of the 30к+
lines of Swift code. Proposed the initial project architecture and led a team of three
developers, taking on the lead role due to strong expertise in SwiftUI. Implemented
audio recording and upload functionality with full background support, audio
format conversion from WAV to lightweight formats, and session lifecycle
management including status tracking. Built a exible model parsing system to
fi
fi
fi
fi
fl
fl
fi
fl
fl
 support dynamic rendering of report carousels from JSON. Set up push
noti cations and implemented a scalable navigation system using path-based
routing. Among other notable features, implemented Live Activities for recording
sessions with StandBy and Always-On display support, addressing speci c
implementation challenges for these modes. Collaborated closely with the
backend team to propose and align the structure of several API endpoints, working
together on approximately 45 endpoints total.

Listen for Everyone — Application based on Listen for Therapist, reworked to
support group use cases instead of the client–therapist model. Rewrote report
summary, data models, and UI components to handle dynamic multi-user
scenarios. Collaborated with the backend team on de ning and designing the
updated API.

Flutter Projects
Vaxley — A COVID-19 companion app. Joined the project during its polishing
phase, focusing on resolving bugs and improving overall stability. Ensured UI
consistency and xed state-related issues to enhance user experience across
various devices.

Beacon Plugin — Developed a custom Flutter plugin for Bluetooth beacon
integration based on the kBeaconPro SDKs for Android and iOS. Designed the
Flutter-side interface and implemented the Android native layer in Java.
Collaborated with another team member responsible for the iOS implementation.
Bridged native and Flutter components using platform channels and integrated the
plugin into the client’s existing app.

Tails — A pet tracking app for cats, developed for an Israeli client. Took over the
project from the client, who initially built the app independently (~3.5к lines of
code). Performed a full codebase refactor, replacing outdated state management
with BLoC and integrating the custom beacon plugin, expanding it to 5.5к+ lines
with new features. Implemented Firebase Authentication, cat and user pro le
management, beacon-pet linking, and movement history storage. Added features
such as a cat gallery with image viewing capabilities and enhanced the search
functionality to locate lost pets.

What’s the Word — Reverse dictionary app using OpenAI API. Started the project
from scratch. Designed app architecture with BLoC and implemented core
features: home screen, search, and favorites. Integrated OpenAI’s Structured
Response API using prompt engineering and Dio as the HTTP client for more
robust and simpli ed error handling. Implemented build avors for development,
staging, and production environments. Later onboarded and mentored a junior
developer to extend the app (details and settings screens) within the existing
codebase (~3к lines of code).

Snareobics — A drum learning application. Tasked with refactoring the app to a
Freemium model and making authentication optional. Implemented conditional
banner displays for purchasing the full version based on criteria such as completed
fi
fi
fi
fi
fl
fi
fi
 training sessions and app usage time. This required understanding the existing
project architecture and modifying it to support the new ow, including xing code
that relied on the previous approach.

Eczema — An eczema tracking application. Inherited a prototype built by
scientists and was asked to re ne it into a client-server application with o ine
mode support. Ultimately decided to rebuild from scratch. Independently
developed the initial 13k+ lines of code, establishing the core architecture and all
major features including authentication, synchronization, o ine mode support,
landscape and tablets support, SVG parsing, pro le management, charts, POEM,
and record creation. Actively participated in numerous discussions with the client,
proposing UX/UI improvements and speci cation re nements. Later onboarded
and mentored new team members, conducting code reviews and discussing
architectural decisions and best practices.

Prototypes & Research
Coherence — Collaborated with a team lead to build an MVP for a biofeedback
app intended to showcase user coherence metrics to potential sponsors. Initially
developed a watchOS prototype, but after discovering limitations in Apple Watch
data frequency, pivoted to Flutter for device integration. Connected external heart
rate monitors via Bluetooth and designed early coherence calculation algorithms.
Conducted extensive research into medical literature to re ne the computation
logic. Prototyped and validated the coherence algorithm in Python using Jupyter
Notebook with visualizations. Later implemented a SwiftUI demo integrating live
heart rate data with the coherence algorithm for real-time feedback. Delivered the
demo to the client, but the project was not continued.

Exhibit Guide App — Created a Flutter app combining two separate web sources:
one with exhibit cards and the other with 360° panoramas. Designed a seamless
user experience allowing users to browse locations, view descriptions and images,
and navigate between panoramas via interactive hotspots. Engineered a dynamic
system to parse a single con guration le and generate navigation points on the
y, enabling smooth transitions between panoramic scenes.

Questionnaire — Developed a proof-of-concept Flutter app for an assessment
platform that parses JSON data to dynamically generate questionnaires and tasks.
The app supports multiple question types, including single-answer and multiple-
answer formats, providing a exible framework for various assessment scenarios.
fl
fl
fi
fi
fi
fi
fi
fi
fl
fi
ffl
fi
ffl