# Seare Hagos

Email: linkmarsto@gmail.com
GitHub: https://github.com/vanoraco
Location: Ethiopia

## Full Stack Developer

I build web and mobile apps end to end. Frontend work in TypeScript, React, and React Native; backend in Python, Go, and PostgreSQL. I've handled everything from database design and API development to Docker deployment and CI/CD pipelines. I write code that's easy to read, easy to test, and easy to hand off.

## Skills

- **Frontend:** React, React Native, Expo, TypeScript, Redux, React Query, HTML, CSS
- **Backend:** Python (FastAPI, Flask), Go, REST APIs, authentication, background jobs
- **Databases:** PostgreSQL, SQL, schema design, migrations, query optimization
- **Infrastructure:** Docker, Docker Compose, Kubernetes (basics), Linux, CI/CD, GitHub Actions
- **Monitoring:** Prometheus, Grafana, structured logging
- **Mobile:** React Native, Expo, EAS, push notifications, offline storage, Stripe, Mapbox

## Selected Projects

### Shoply — E-commerce app (React Native, FastAPI, PostgreSQL, Stripe)

A full e-commerce app with payments, orders, and an admin dashboard.

- Built the product catalog with search, filters, and infinite scroll.
- Built cart and checkout with Stripe payments and order confirmation via webhooks.
- Designed the PostgreSQL schema for products, inventory, orders, and users, with stock that decrements inside a transaction.
- Added JWT auth with refresh tokens, password reset, and admin-only routes.
- Set up push notifications for order status updates and release builds with EAS.

### ChatMate — Real-time chat (React Native, TypeScript, WebSockets, PostgreSQL)

A chat app with typing indicators, presence, and push notifications.

- Built the WebSocket layer with automatic reconnection and message delivery receipts.
- Built the conversation list, chat threads, and media sharing, with messages appearing instantly before the server confirms.
- Designed the message schema with unread counters and indexed queries for fast loading.
- Kept chat working offline and synced on reconnect.
- Wrote tests for the messaging protocol so client and server never drift apart.

### FinTrack — Finance dashboard (React, Go, PostgreSQL)

A personal finance dashboard for budgets and reporting.

- Built the dashboard UI with charts, filterable tables, and CSV export.
- Wrote the Go API with clean middleware and structured logging.
- Used materialized views to keep daily summary queries fast as data grows.
- Added transaction categories, budget alerts, and scheduled email reports.
- Deployed with Docker Compose and GitHub Actions.

### Duka — Delivery tracking (React Native, Expo, Mapbox, Go)

A delivery tracking app with live vehicle positions, geofencing, and trip history.

- Built live map screens with custom markers and follow-mode so deliveries can be watched in real time.
- Collected locations in the background in batches to save battery.
- Wrote the Go ingestion API for high-volume location events.
- Added geofence alerts and trip replay from time-based PostgreSQL queries.
- Buffered locations offline and synced when connectivity returned.

### AddisMonitor — Monitoring app (React Native, FastAPI, PostgreSQL, Docker)

A cross-platform monitoring app with a FastAPI backend.

- Built the API with authentication, rate limiting, and structured error handling.
- Designed the PostgreSQL schema with JSONB payloads and time-based queries.
- Built the mobile client with automatic token refresh and cached API responses.
- Set up Docker Compose with Nginx for local development and production.
- Used Alembic to keep database migrations versioned.

### Velai — Background job system (Python, PostgreSQL)

A job queue with scheduling, retries, and persistent state.

- Built typed job definitions with retry policies and exponential backoff.
- Wrote the PostgreSQL backend so jobs can be claimed, acked, and failed safely across workers.
- Added dead-letter handling and at-least-once delivery guarantees.
- Wrote contract tests to keep implementations behaviorally aligned.

## Work History

### Freelance Software Engineer / Independent Projects

Full stack work across web and mobile apps, API design, data processing, and deployment.

- Built and shipped React and React Native apps, including state management and API integration.
- Designed and implemented REST APIs with proper authentication and error handling.
- Designed and optimized PostgreSQL schemas, indexes, and slow queries.
- Built ETL pipelines for extraction, transformation, and bulk loading.
- Set up Docker environments and automated deployment pipelines.
- Reviewed code, wrote documentation, and fixed production issues.