Conor O'Sullivan Mitchell

Full Stack Developer focused on building systems that work well and are pleasant to maintain.

Vilnius, Lithuania, EET

About

Full-stack engineer with deep TypeScript experience. I enjoy the puzzle of designing clean architectures for complex problems.

Currently exploring Go and systems programming. I pick up new languages quickly—more interested in solving the right problem than being married to a specific stack.

Outside of code, I follow Formula 1 closely. The engineering challenges, constant iteration, and balance between innovation and reliability resonates with how I think about software.

Work Experience

Vertebrate

2023 - 2025

Full Stack Software Engineer

Built core systems for a medical practice management platform:

  • Multi-tenant authentication with role-based access control across organizations, practices, and practitioners.
  • Patient charts & document management—data architecture, S3 upload with encryption, HIPAA-compliant storage, fine-grained sharing (per-chart/per-file), template system, and fast search/filtering.
  • Booking engine—scheduling algorithm generating slots dynamically based on practice hours, practitioner availability, service duration, and holiday configurations.
  • Notification system—AWS EventBridge architecture for SMS reminders, practitioner alerts, and patient action triggers with configurable delivery rules.
  • Surveys & feedback—event-driven surveys (e.g., post-appointment triggers), practice UI for creation and response analytics.
  • Secure patient messaging—HIPAA-compliant chat with file/image sharing.
  1. Remote
  2. TypeScript
  3. React
  4. Next.js
  5. Node.js
  6. AWS
  7. Pulumi
  8. PostgreSQL

Freelance Development

2020 - 2023

Full Stack Developer

TypeScript/React projects for small businesses. Short-term engagements; several clients have since shut down or pivoted.

  1. Remote
  2. TypeScript
  3. React
  4. Tailwind
  5. Node.js

Skills

  1. TypeScript
  2. React / Next.js
  3. Node.js
  4. Tailwind CSS
  5. PostgreSQL
  6. Redis
  7. AWS (Lambda, S3, EventBridge)
  8. Pulumi
  9. System Design

Projects

Crammr

In Development

AI-powered study application. Upload documents (PDF, DOCX, images), converts to structured notes via xAI, generates quizzes for active recall. Tracks quiz performance to surface weak areas and guide focused study.

  1. Next.js
  2. Supabase
  3. xAI/Grok

Languages

English (Native) Lithuanian (Conversational)