
Andrii Naidenko
Verified Expert in Engineering
Full-stack and Mobile Developer
Athens, Central Athens, Greece
Toptal member since August 26, 2019
Andrii is a full-stack engineer with 19 years and a master's degree in computer science: Node.js back ends, Angular and React front ends, and a mobile app with 100,000+ installs he has run solo since 2019, across nine Toptal engagements with several repeat clients. He now designs AI-native delivery systems that carry a product from the design file to post-release crash triage — agents plan, build, review and verify on real devices, with a human only at the decision gates.
Portfolio
Experience
- Full-stack - 19 years
- Node.js - 12 years
- Amazon Web Services (AWS) - 12 years
- Mobile App Development - 10 years
- Ionic - 10 years
- TypeScript - 9 years
- Angular - 9 years
- Capacitor - 7 years
Preferred Environment
Visual Studio Code (VS Code), MacOS, Claude Code, Xcode, Android Studio, Amazon Web Services (AWS)
The most amazing...
...software I've built is the mobile app 100,000+ shift workers run their workday through — punches, schedules, GPS and geofences, offline when there's no signal.
Work Experience
Senior Mobile Developer
Buddy Punch
- Owned the iOS and Android app end to end as its sole developer for seven years — architecture, features, native integrations and every store release — 3,200+ commits behind a product with 100K+ installs and a 4.9-star App Store rating.
- Carried the app through three platform generations to Angular 21, Ionic 8 and Capacitor 8, and moved iOS from CocoaPods to Swift Package Manager — so a seven-year-old codebase still ships on current tooling.
- Built Offline Mode, the product's most requested feature of 2025: employees punch in and out and take breaks with no connection, and everything reconciles with the server the moment the network returns.
- Built the GPS layer the product sells on: background tracking during shifts, geofence enter and exit alerts, route maps, precise-location enforcement and anti-spoofing safeguards — on phones and tablets alike.
- Migrated push notifications from OneSignal to Firebase Cloud Messaging across the installed base.
- Built the security layer end to end: multi-factor sign-in with passkeys, recovery codes and trusted devices, plus native credential autofill through iOS Password AutoFill and Android Credential Manager on platform secure storage.
- Built the workflow features managers run their teams on: shift trade and cover requests with approvals, availability, time-card acknowledgment, group punch for whole crews, and manual-punch notes for kiosk mode.
- Led the app-wide restyle onto the web product's design system — full dark mode on both platforms — and shipped the Spanish (es-MX) localisation.
- Wrote the native code where plugins fell short: a custom Capacitor plugin in Swift and Java for kiosk and guided-access mode, an in-house fork of the barcode scanner when its vendor dropped SPM, and iPad resizable-window support ahead of iPadOS 27.
Full-stack Developer
Brokerloop
- Owned the engine room of the platform: six years and 1,800+ commits on the Node.js API behind every listing, contact and campaign — the layer brokerages depend on to run their day.
- Built the platform its own video conferencing product — scheduled rooms, live streaming, cloud recording and screen share, syndicated to YouTube, Facebook and Instagram — so brokerages could host their community without ever leaving it.
- Built the revenue engine: Stripe subscriptions with tiered plans, instant mid-cycle upgrades and credit-based limits, so brokerages could buy, upgrade and scale without ever talking to sales.
- Built the platform's own email infrastructure — a self-hosted SMTP proxy with rate limiting, automatic failover and bounce intelligence — so brokerage campaigns land in inboxes instead of spam folders.
- Opened the platform to AI: documented the entire API as an OpenAPI spec, then built an MCP server so assistants like Claude can run the product through it.
- Mentored the team and set the engineering bar: code reviews, on-call DevOps in AWS and full ownership of releases — so the platform shipped on a predictable cadence.
- Gave brokerages one-click social reach: a cross-posting engine for Facebook, Instagram, X and LinkedIn with scheduling and per-platform formatting, so one post covers every network.
- Connected print marketing to the web: QR codes generated for every listing and bio site, with scan-to-visit conversion tracked in the dashboard — so agents could finally measure their flyers.
- Put a direct line to clients in the product: SMS and MMS campaigns on Plivo with delivery tracking, so brokerages could reach their whole contact list from the same dashboard.
MEAN Full-stack Developer
RentWise
- Built the entire learning engine behind the platform: course authoring, quizzes, certificates and pacing rules that make sure renters actually absorb their rights instead of clicking to the end.
- Turned the platform into a paid product: PayPal checkout for course purchases, plus registration and activity exports so administrators could see who was actually learning.
- Brought the video library in-house: adaptive HLS streaming with quality selection, and a pipeline that imports YouTube courses with subtitles into the platform's own storage — no more dependence on a third party.
- Replaced dead PDF worksheets with living ones: budgets that total themselves as renters fill them in, plus a Q&A flow that puts housing providers one message away.
- Ran the security audit and fixed what it found: server-side request forgery, cross-site scripting, session hijacking and broken access control — on a platform holding renters' personal data.
- Put every property on the map: an ArcGIS geocoding layer that turns an address into its neighbourhood context — the services and housing around it — in one view.
- Gave tenants a place for their paperwork: leases, property photos and issue reports in one vault, so a renter can prove what was agreed and what went wrong months later.
- Rebuilt authentication on one path: a reworked data model and JWT flow that replaced scattered ad-hoc role checks with a single rule the entire API obeys.
- Built and maintained the platform end to end across three engagements from 2022 to 2025 — an education system that teaches renters and landlords their rights.
Senior Cross-Platform Developer
USC ICT (Institute for Creative Technologies)
- Took a desktop-only mental-health support app to the phone: responsive layouts, modal scrolling and phone-sized forms, quizzes and assessments — so people could reach help from the device they actually carry.
- Turned a web app into a shippable product: packaged it with Ionic and Capacitor for the App Store and Google Play, so research work could reach users as a real mobile app.
- Redesigned a dozen self-help forms — journals, planners, worksheets — to work on a phone and on paper alike, so people could fill them in wherever they were, then print a clean copy.
- Fixed scoring and flow defects the research team reported across the assessments and the new-user tutorial, including a halt that trapped users mid-conversation.
Senior Full-stack Developer
Freelance Clients
- Delivered a revolutionary content licensing system based on blockchain technologies with a marketplace feature that makes licensing, validating, and monetizing digital content as easy as sending a Venmo payment.
- Implemented a social media marketing platform for franchise organizations and distributed teams to empower central marketing departments with a system to simultaneously distribute consistent hyper-local content for all their independent sales reps.
- Implemented a smart and modern cloud-based task tracker for project coordination and sprint planning. It revolutionized Inovo Studios and OnCue Technology's workflows and became one of the year's highlights for the client.
- Implemented a Gitflow development process with continuous integration and delivery pipelines for microservices hosted on AWS cloud.
- Recognized as a top-rated developer with a 100% job-success score. Clients were highly satisfied with the delivered services and left positive references on the platform.
- Provided regular expert consultation and technical guidance on software development and design projects for many clients.
- Performed code reviews and optimized software architecture and security concerns of clients' products.
- Built the web and mobile experience for Sellr, a retail platform that engages shoppers online and in the aisle to drive traffic and sales — AngularJS on the web, Ionic on mobile, with a reworked async model on the back end.
Lead .NET Software Engineer
EPAM Systems
- Ran the project as Scrum master for a team of 6–10: took requirements straight from the customer, ran the reviews and retrospectives, and brought every newcomer up to speed.
- Built the financial portlets traders watch the markets through: stock-exchange monitoring on the Thomson Reuters platform, running live on the client's terminals.
- Designed the MVVM-C JavaScript framework the whole portlet suite was rebuilt on, and shipped WPF desktop apps to the Bloomberg App Portal — setting the front-end pattern the team followed.
- Brought the team its first JavaScript unit tests and a continuous integration pipeline, and made the trading apps usable on touch screens — in 2012, before either was standard.
- Trusted to hire: interviewed senior .NET and JavaScript candidates on the company's behalf, and onboarded the ones who made it in.
- Spoke to rooms of up to 100 engineers at public IT conferences on Knockout.js, TDD, JavaScript, Entity Framework, Brightcove and the Bloomberg App Portal — the company's voice on front-end practice.
- Twice promoted in three years, from engineer to lead, on the company's own recognition of technical growth.
.NET Software Engineer
GlobalLogic
- Worked on CustomCD, DigitalRiver's burn-on-demand eCommerce service: the admin and partner-support web applications behind orders fulfilled across the US and Germany.
- Built the back-end services that moved orders out the door: packaging, shipment and reporting, plus the notification system telling customers where their order was.
- Integrated the PlanetPress publishing engine so every invoice and business document reached its recipient in the format they actually wanted — print, email or file.
- Built the reporting layer on Microsoft Reporting Services, so the business could finally see its order and fulfilment numbers without asking engineering.
- Integrated and maintained the enterprise resource planning system that unified planning, accounting and analysis across the company's operations.
Experience
Buddy Punch — Time Tracking and Scheduling for Shift Teams
https://buddypunch.com/I have been its sole developer since 2019. In that time the app went through three platform generations to Angular 21, Ionic 8 and Capacitor 8, gained an offline mode that reconciles punches when the network returns, a GPS layer with background tracking, geofence alerts and anti-spoofing safeguards, multi-factor sign-in with passkeys, native credential autofill, a full dark-mode restyle, Spanish localisation and a push-notification migration to Firebase — plus a custom Capacitor plugin in Swift and Java where no plugin existed.
Technologies: Ionic, Capacitor, Angular, TypeScript, Swift, Java, iOS, Android, Firebase Cloud Messaging, Geolocation, Offline-first, Capacitor Plugin Development, Swift Package Manager, CocoaPods, Ionic Appflow, PrimeNG, SCSS, Raygun, Google Analytics.
Brokerloop | Professional Network and Marketing Platform for the Real Estate Community
https://www.brokerloop.com/I owned the Node.js platform API end to end for six years: MLS listing ingestion, CRM and contacts, subscription billing on Stripe, a self-hosted email infrastructure, and the live-streaming events platform brokerages host their community on.
Technologies:
Node.js, Express.js, TypeScript, AngularJS, React, MongoDB, MySQL, Mongoose, Sequelize, Stripe, Redis, Haraka, SendGrid, AWS, Docker, OpenAPI, RETS, OData, Socket.IO, WebRTC, HLS, YouTube API, Google APIs, GitFlow, and MCP.
RentWise | Rental Education Platform
https://www.rentwise.org/I built the learning engine the platform runs on — course authoring, quizzes, certificates and pacing rules — plus PayPal checkout, adaptive video streaming, an ArcGIS mapping layer and the security hardening that followed the audit.
Technologies:
MEAN, Angular, Angular Material, Node.js, Express.js, MongoDB, AWS, Amazon S3, CloudFront, AWS Elemental MediaConvert, Heroku, PayPal API, JWT, Passport.js, ArcGIS, GeoJSON, video.js, HLS, and TinyMCE.
AI-Native Engineering System for a Mobile Product Team
Its distinguishing feature is that the guardrails are deterministic rather than advisory: eleven hooks enforce mechanically what documentation alone cannot — blocking credentials from ever reaching a session, refusing a client-facing message missing its recipients, catching edits that silently land in the wrong place. Each exists because a specific failure happened once and was made impossible afterwards.
Around it sits a self-improving knowledge base of 131 codified lessons, kept in sync by an automated check. Verification is multi-modal: agents drive real iOS and Android devices, read QA screen recordings and capture on-screen motion as video, instead of trusting a green build. I also designed the release process the team now runs on.
Technologies:
AI Agents, Prompt Engineering, Model Context Protocol (MCP), Claude Code, Playwright, Node.js, Bash, Python, Git, CI/CD Pipelines, and Azure DevOps.
Claude Code Plugin Marketplace — Open-Source Developer Tooling
https://github.com/anaidenko/claude-pluginsTwo plugins ship through it. claude-notify-resume delivers desktop notifications that carry the name of the conversation that produced them and reopen that exact session when clicked — built for a workflow running many parallel agent sessions at once. claude-video-digest turns any video into a readable digest: a timestamped contact sheet, extracted frames and a transcript, with a loudness probe that detects silent audio tracks so the tool never invents captions for a video that has no speech.
Both plugins ship with zero runtime dependencies, their own test suites running on macOS and Linux, and full documentation. I designed, built, released and maintain all three repositories, including semantic versioning and changelogs.
Technologies:
Node.js, Bash, TypeScript, Git, GitHub Actions, CI/CD Pipelines, Docker, FFmpeg, macOS, and Linux.
Virtual Research Navigator — Conversational Mental-Health Support on Mobile
https://ict.usc.edu/I joined the team to take that Angular interface off the desktop and onto the phone. I packaged it with Ionic and Capacitor for the App Store and Google Play, rebuilt the layouts, modal scrolling and forms for a phone-sized screen, redesigned a dozen self-help forms to work on screen and on paper alike, and fixed scoring and flow defects the research team reported across the assessments and the new-user tutorial, including a halt that trapped users mid-conversation.
Technologies: Angular, NgRx, Ionic, Capacitor, Cordova, TypeScript, SCSS, Bootstrap, Responsive Design, iOS, Android.
BitRights Platform for Licensing on Blockchain
I built the entire front end and public-facing app and contributed to the Node.js API: IPFS storage for licensed content, Merkle-tree proofs, and payments.
Technologies:
Angular, Angular Universal, Bootstrap 4, TypeScript, Chart.js, ng2-charts, Node.js, Express, Mongoose, Stripe, AWS, Docker, RabbitMQ, JWT, SendGrid, IPFS, Stellar, Merkle Tree, GitFlow, and CircleCI.
Seller Platform for Retailers
Technologies:
MEAN, Ionic, AngularJS, TypeScript, MySQL, Socket.IO, Chart.js, Stripe, OAuth, Passport, Algolia Search, Segment, New Relic, Mailgun, MailChimp, Heroku, CloudFront, CircleCI, GitFlow, Git.
TeamPlanner: A Modern and Smart Cloud-based Task Tracker
Technologies:
MEAN, Material Framework, Socket.IO, Chart.js, Heroku, Amazon S3, CloudFront, Passport, Slack, NewRelic, Mailgun, Grunt, Lodash, Less, Beanstalk, and Git.
YipYip Platform for Enterprise Blogging and Social Media Posting
Technologies:
AngularJS, Material Framework, CoffeeScript, Jade, Express.js, Amazon S3, LABjs, Grunt, Lodash, Karma, Mocha, Jasmine, and Heroku.
CardKit Website Builder
Technologies:
MEAN, Material Framework, Amazon S3, CloudFront, Route 53, Stripe payments, FileStack, OAuth2, NewRelic, Passport, and Medium Editor
Spotlight Casting Platform
https://spotlight.com/I worked on the back-end services behind auditions and video clips: ServiceStack and Web API endpoints over SQL Server, with FFmpeg handling the clip processing.
Education
Master's Degree in Computer Science
Kharkiv National University of Radio Electronics - Kharkiv, Ukraine
Certifications
Programming in HTML5 with JavaScript and CSS3
Microsoft
Windows Communication Foundation Development with Microsoft .NET Framework
Microsoft
Web Apps Development with MS .NET Framework
Microsoft
Skills
Libraries/APIs
Node.js, Stripe API, Flexbox, Stripe, REST APIs, React, RxJS, Socket.IO, jQuery, jQuery UI, Facebook API, Google API, X (formerly Twitter) API, Slack API, Sockets, Google Maps API, Google APIs, Playwright, OpenAPI, YouTube API, CocoaPods, Chart.js, Highcharts, Google Analytics API, Windows Forms (WinForms), Web API, Entity Framework, LINQ, Mailchimp API, Sinon.JS, Chai, NgRx, FFmpeg, ArcGIS, WebRTC, PayPal API, Passport.js, PrimeNG
Tools
Slack, Git, PM2, Sequelize, Mongoose, Capacitor, Claude Code, Claude, CircleCI, Docker Hub, Jira, Karma, Asana, Toggl, Webpack, Gulp, Grunt, Angular Universal, Xcode, Android Studio, SendGrid, RabbitMQ, Mocha, Trello, Pivotal Tracker, Bower, Beanstalk, Subversion (SVN), Amazon CloudFront, Google Analytics
Languages
HTML, TypeScript, JavaScript, HTML5, CSS, SQL, SCSS, C#, Sass, Less, Bash, UML, Python, Swift, Java
Frameworks
Bootstrap, Angular, AngularJS, Ionic, Angular Material, Bootstrap 3+, OAuth 2, Jasmine, Express.js, Tailwind CSS, JSON Web Tokens (JWT), Knockout (Knockout.js), Redux, .NET, Protractor, Next.js, ASP.NET, ASP.NET MVC, Windows Presentation Foundation (WPF), ServiceStack, NHibernate, PhoneGap, Koa, Video.js
Paradigms
Test-driven Development (TDD), Agile Software Development, Kanban, Clean Code, Asynchronous Programming, Continuous Integration (CI), Continuous Delivery (CD), MEAN Stack, REST, Mobile Development, Unit Testing, Functional Testing, Scrum, GRASP, Design Patterns, Object-oriented Design (OOD), Agile, Model Context Protocol (MCP), Azure DevOps, Behavior-driven Development (BDD), Automation, Offline-first Development, Cross-platform
Platforms
MacOS, Docker, Heroku, Amazon Web Services (AWS), iOS, Android, Visual Studio Code (VS Code), Firebase, Amazon, YouTube, Algolia
Storage
MongoDB, MySQL, Amazon S3 (AWS S3), NoSQL, Redis, Microsoft SQL Server, PostgreSQL, SQLite, Elasticsearch
Other
Cordova, SOLID Principles, GitFlow, Web Development, Mobile App Development, Front-end Development, Full-stack, Back-end Development, Slack App, Full-stack Development, Software as a Service (SaaS), Front-end, Back-end, APIs, Ionic Appflow, Push Notifications, Geolocation, Architecture, Video Conferencing, OData, AI Agents, Prompt Engineering, CI/CD Pipelines, SMTP, Server-side Rendering (SSR), GitHub Actions, Windows Communication Foundation (WCF), Domain-driven Design (DDD), Progressive Web Applications (PWAs), GeoJSON, RETS, Open Source, Process Design, Anthropic, Video Conferencing Bridges, HTTP Live Streaming (HLS), PayPal, TinyMCE, AWS Elemental MediaConvert, Raygun, Capacitor Plugin Development, Cross-platform App Development, Responsive Design
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