Caitlyn Carmabella Nayeli

Helsinki, Finland caitlyn.c.nayeli@gmail.com| carmabella.com | linkedin.com/in/caitlyn-carmabella

Professional Summary

Full-stack developer and UX designer who ships production-ready platforms at exceptional velocity. Built a 146,000-line enterprise marketplace in 8 weeks and a 175,000-line multi-platform integration suite, both as sole developer. Strong foundation in object-oriented programming (C, C++, Java, Python) applied to modern TypeScript and React development. Specialized in accessible, user-centered experiences with expertise in React, React Native, TypeScript, PostgreSQL, and full-stack architecture from database to deployment. Fluent in English; actively learning Finnish (Suomeni paranee aktiivisesti).

Skills

Development: JavaScript/TypeScript, React, React Native/Expo, Next.js, Node.js, HTML5/CSS3, SQL, PostgreSQL, Supabase, Git, API Integration, OOP (C, C++, Java, Python)

UX/Design: User Research, Information Architecture, Wireframing, Prototyping, Usability Testing, Accessibility (WCAG), Responsive Design

Tools: Figma, Android Studio, Tailwind CSS, Adobe Suite, Jira

Specialized: Cross-platform mobile development, Database architecture and optimization, Real-time systems, AI integration (Claude API), Payment system integration, Multi-language internationalization

Recent Projects

Bluumo - Enterprise Wellness Marketplace Client Project (Founding Team Member) | November 2025 - February 2026 bluumo.fi

Built a production-grade wellness marketplace from scratch in 8 weeks as sole developer: 146,000 lines of TypeScript across 387 files, 96 screens serving four user types, and 2,040 git commits during development.

  • Replaced manual phone-booking bottleneck with automated two-sided marketplace; full booking, scheduling, and payment pipeline

  • Corporate B2B portal with employee management, approval workflows, cost center tracking, and invoice analytics

  • Payment integration: Visma Pay (Finnish banks, cards, MobilePay) and Edenred (wellness benefit cards), with Holvi, Smartum, and ePassi infrastructure ready

  • 33 serverless edge functions (Deno) for webhooks, payments, AI, and email delivery

  • AI concierge "Helmi" powered by Claude Sonnet 4 for booking assistance and customer support

  • In-app voice calling via Agora SDK for direct customer-provider communication

  • Row Level Security policies enforcing multi-tenant data isolation across four user roles

  • Performance: reduced interaction response from 1,280ms to sub-200ms via StyleSheet memoization

  • 7 languages with 2,660+ translation keys across 11 namespaces

Tech Stack: Expo, React Native, React 19, TypeScript, Supabase, PostgreSQL, Visma Pay, Edenred, Agora, Mailgun, Claude API, Vercel

Suumio - AI Companion Journal Personal Project | 2025 - 2026 suumio.com

Production AI journaling app built as sole developer. 32 distinct AI companions, each a different emotional specialist (anxiety, grief, creativity, recovery, and more), running natively on iOS, Android, and web from a single codebase. Live with real users and Stripe billing across four subscription tiers, localized into 32 languages.

  • 32 companion personalities defined by JSON config files (species, tone, focus areas, system prompt, feature flags); adding or reshaping a companion requires no app logic changes

  • Multi-companion Room Chat orchestrating up to 4 companions simultaneously, each maintaining distinct voice and specialty

  • Shared Spaces: multi-user rooms with companion participation across accounts

  • Token-based credit billing (1 credit = 1k tokens) with Stripe live-mode webhooks and one-time top-ups

  • Prompt engineering for 32 distinct personalities with carefully differentiated focus areas; structured tool-use per companion (context notes, timers, web search)

  • Static/dynamic prompt split to maximize Anthropic cache hit rates; prompt injection sanitization on all user input

  • Full i18n: 32 locale TypeScript files typed against a TranslationKeys union derived from the English source, enforced at compile time

  • Automated bulk translation pipeline via Claude Haiku with regex-based in-place locale patching

  • Voice I/O with per-companion ElevenLabs voice profiles (stability, style, and speed tuned per character)

Tech Stack: Expo, React Native, TypeScript, Supabase, PostgreSQL, Anthropic Claude API, ElevenLabs, Stripe, Node.js, Nginx

CarmaClouds - Multi-Platform VTT Character Sync Suite Open Source (MIT License) | 2024 - Present carmaclouds.vercel.app

175,000-line multi-platform character synchronization system built as sole developer. Browser extensions for Chrome and Firefox, integrations for three VTT platforms, and a Discord bot. Currently on hold to prioritize revenue-generating work.

  • Adapter pattern architecture: single DiceCloud character parsed once, transformed for each platform's unique data structures

  • D&D 5e rule engine handling 50+ edge cases (Hexblade's Curse, finesse weapons, expanded crit ranges, class features)

  • Chrome MV3 and Firefox MV2 support from a single codebase via custom ESBuild pipeline

  • Real-time sync via Supabase subscriptions; platform integrations for Roll20, Owlbear Rodeo, Foundry VTT, and Discord (20+ slash commands)

Tech Stack: JavaScript, TypeScript, Node.js, ESBuild, Supabase, PostgreSQL, Next.js, React, Discord.js, Meteor DDP, Chrome/Firefox Extension APIs

Modular Business Website Framework Client Projects | 2025 - 2026

Reusable architecture deploying fully customized small business sites in 3 to 5 hours from a single codebase, handling e-commerce, bookings, galleries, and admin dashboards.

  • Initial framework build: approx. 8 hours. Subsequent client deployments: 3 to 5 hours (40 to 60% reduction)

  • CSS variable-based theming with automatic WCAG AA contrast calculation

  • Configuration-driven deployment: update database settings, swap assets, deploy

  • WebP image optimization: 94.7% file size reduction (902KB to 48KB)

  • Dynamic imports reducing initial bundle by approx. 40%; Lighthouse Performance score 95+

Live Sites: designsbyadino.com, amyshenhouse.com, umbralgarden.com Tech Stack: Next.js 16, React 19, TypeScript, Tailwind CSS 4, Supabase PostgreSQL, Square Payments, Resend

Dice Cat - Tabletop Gaming Matchmaking App Personal Project | 2024 - 2026 play.google.com/store/apps/details?id=com.dicecat.app

Cross-platform mobile app connecting tabletop gamers for in-person play, built end-to-end from UX research through live deployment on Google Play.

  • User research with 15+ participants, validated Figma prototype, full production app

  • Multi-dimensional matchmaking: game libraries, PostGIS radius queries, availability overlap, and weighted play preferences; optimized queries from 3 to 5 seconds down to sub-500ms

  • Real-time connections, in-app encrypted messaging, custom layered SVG avatar builder

  • 10,000+ title game database; complete rebrand from "Meeplr" following trademark research

Tech Stack: React Native (Expo), TypeScript, PostgreSQL, Supabase, FCM, Android Studio

Professional Experience

Freelance Full-Stack Developer and UX Designer July 2023 - Present | Remote

Managing 4+ concurrent client projects, delivering end-to-end solutions from user research through deployment.

Divergent Realms | divergentrealms.com

  • 5-hour homepage redesign outperformed previous agency's 3-month, $3,000+ version in A/B testing

  • Architected three-path information structure serving distinct user journeys (browse GMs, direct booking, join existing games)

  • Rebuilt WordPress site on Squarespace with custom booking systems and payment flows

  • Built hidden dungeon-crawl text adventure (Konami code trigger) demonstrating advanced JavaScript and game logic

NeuroSweetSpot | neurosweetspot.com

  • Complete redesign delivered in 1 week: platform migration, IA restructuring, accessibility, and custom features

  • Organized 120+ articles into 3-level hierarchy across 6 user journeys

  • WCAG AA implementation for neurodivergent users: screen reader optimization, high contrast, semantic HTML

  • Built 3,000-line JavaScript creature-catching game with Supabase integration and site-wide search

UX Designer (Volunteer) MNFurs | November 2022 - December 2023 User research, wireframing, and stakeholder collaboration for website redesign initiative.

Owner and Entrepreneur Carmabella Creations | 2016 - 2023 Built and scaled personal brand business with full-stack technical implementation, e-commerce, and customer engagement.

IT Consultant and Full-Stack Developer UnVale | 2021 - 2022 Embedded consultant with 3-person early-stage startup. Consulted on architecture decisions, shipped features end-to-end without a PM layer, worked directly with founders. Tech Stack: JavaScript, React, HTML, CSS, SQL

IT Assistant, Researcher and Developer Clemson University | 2012 - 2016 Independent research in Human-Centered Computing; collaborated with VR Lab on STEM program for young women; developed VR applications in C#, Java, and web technologies.

Education

Bachelor of Applied Science in Information Technology Metropolia University of Applied Sciences | Espoo, Finland | August 2025 - Present

User Experience Design Certification Prime Digital Academy | Minneapolis, MN | April 2023 - July 2023 Intensive UX program covering Kano Analysis, User Journey Mapping, Wireframing, Prototyping, Usability Testing, and Persona Generation applied to real-world client projects.

Computer Engineering and Computer Science (coursework) Clemson University | Clemson, SC | 2012 - 2016 Foundation in OOP through C, C++, Java, and Python. Focused on human-computer interaction, software engineering, and web design.

What Sets Me Apart

I Ship Products at Scale: Built a 146,000-line enterprise marketplace and a 175,000-line multi-platform integration suite as sole developer. Published mobile app on Google Play. Live platforms serving real users and generating revenue.

Exceptional Velocity: Rebuilt an entire marketplace in 8 weeks (2,040 commits); designed a homepage that beat a 3-month agency version in 5 hours; delivered complete redesigns in 1 week.

Full-Stack Mastery: User research through database architecture, payment integration, native mobile apps, and production deployment. Every layer of the stack, independently.

Architectural Thinking: Adapter pattern systems, configuration-driven frameworks, and payment-processor-agnostic architectures built to scale across multiple deployments.

Accessibility Champion: Deep understanding of neurodivergent users and WCAG standards, creating genuinely inclusive experiences for diverse audiences.

Solo Capability with Team Experience: Delivered complete products independently (Bluumo, CarmaClouds, Suumio, Dice Cat) while collaborating effectively with stakeholders, founders, and clients.