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ljmerza/README.md

Leonardo Merza

Senior Software Engineer | Raleigh, NC

Website GitHub Email Followers

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About Me

Backend engineer with 10+ years building distributed, asynchronous systems, mostly in Python with some Go and Java. I work on the server side: event pipelines, task queues, cache layers, and the concurrency and backpressure controls that keep them correct under load.

Right now I build B2B backend services for a network of RF sensors that produces 100k+ events a day, running on ECS and EKS with Terraform on AWS. Day to day that means asyncio and FastAPI services, Celery workers on SQS with retry and dead-letter queues, Kafka consumers, Redis/Valkey and Memcached for caching, DynamoDB for high-write access patterns, and Elasticsearch/OpenSearch for search and event indexing at that volume.

I spent a good chunk of those years in React and TypeScript, so I can own a feature end to end. The problems I go looking for are the distributed ones, though. Outside of work I write Home Assistant integrations and cards and run a self-hosted home lab.

Tech Stack

Languages           │ Python, Go, TypeScript, Java, SQL
Distributed & Async │ asyncio, Celery, AWS SQS, Kafka
Caching & Search    │ Redis/Valkey, Memcached, Elasticsearch/OpenSearch
Data Stores         │ PostgreSQL, MySQL, DynamoDB, InfluxDB
Services & APIs     │ FastAPI, Django, Flask, NestJS, OpenAPI/Swagger
Infrastructure      │ Docker, AWS ECS & EKS, Terraform, GitHub Actions, Prometheus
Testing             │ Pytest, Playwright, Jest, React Testing Library
Frontend            │ React, Redux, TypeScript, Angular, Tailwind, Storybook

Featured Projects

Home Assistant Ecosystem

Project Description Stars
ac-infinity-airtap-ble Local BLE control of AC Infinity AirTap register vents from Home Assistant. Sets fan speed and temperature without the vendor cloud Stars
calendar-card Google Calendar card for Lovelace UI (archived) Stars
fitbit-card Fitbit health metrics dashboard card Stars
FrigateClassifier Dog breed and bird species classification for Frigate detections Stars
ha-our-groceries Our Groceries shopping list integration (archived) Stars
harmony-remote-card Logitech Harmony Hub remote-control card for Lovelace Stars
irrigation_manager Scheduled watering for valve and switch entities in Home Assistant. Conditions on rain, forecast, temperature, wind, moisture and occupancy, plus a sidebar panel Stars
light-entity-card Card for controlling any light or switch entity Stars
orbit-bhyve-ble Local BLE control of Orbit B-Hyve sprinkler timers from Home Assistant. Works without the cloud after setup Stars
soil-temp HACS integration exposing soil temperature and moisture sensors via ClearAPI Stars
tracking-number-card Display package tracking information Stars
tracking-numbers Home Assistant integration that pulls tracking numbers from 40+ shipping providers Stars
utilities_email_tracker Polls IMAP and parses utility-bill emails into a Home Assistant sensor Stars
utilities_email_tracker_card Lovelace card for displaying parsed utility-bill emails Stars

Open Source Projects I Maintain

Project Description Language
billy-bass Sound-reactive Big Mouth Billy Bass on an Arduino Uno and Adafruit Motor Shield v2. A microphone module drives the mouth, head, and tail C++
checkpoint-pihole Web application for backing up Pi-hole v6 instances via the Teleporter API Python
cradlewise-rtsp-bridge Turns every Cradlewise Smart Crib on an account into a local RTSP stream for Frigate, Blue Iris, Scrypted, or any other NVR. Holds one WebRTC subscriber per crib and feeds it into mediamtx Python
FlowHistory Backup and restore tool for Node-RED flow files, with scheduled backups, visual diffs, multi-instance support, and notifications Python
frigate_plate_recognizer License plate recognition integration for Frigate NVR Python
latchpoint Self-hosted alarm system that integrates with Home Assistant, MQTT, Z-Wave JS, and Frigate. Includes a rules engine for automated responses and live status updates Python
nodered-mcp MCP server for reading, querying, and editing a Node-RED flows.json. Canvas aware, with a layout gate that refuses edits that would collide with existing nodes or groups Python
py-our-groceries Unofficial async Python client for the Our Groceries shopping list API, published to PyPI as ourgroceries. Powers the Home Assistant Our Groceries integration Python
unifi_firmware Weekly scraper and web UI for UniFi firmware releases. Reads the download JSON backend directly, groups releases by device, and stores everything in SQLite Python
wifi-shepard Docker daemon that watches a wireless network and re-roams misbehaving 2.4 GHz IoT clients across APs through a brand-agnostic controller interface, UniFi first Python

DevOps & Infrastructure

Project Description
rsync-exporter Export rsync statistics to Prometheus
snapraid-collector Prometheus metrics exporter for SnapRAID

Open Source Contributions

Most of my open source work is in the Home Assistant ecosystem. That includes integrations for third-party services, Lovelace cards for dashboards, and a few tools around Frigate NVR for license plate recognition and object classification.

Experience

  • Senior Software Engineer @ Epiq Solutions (2022 - 2024)

    • Full-stack development with React, TypeScript, Python, and Go
    • Kubernetes cluster management and AWS infrastructure with Terraform
    • Led JavaScript to TypeScript migration and modernized build tooling
  • Senior Software Engineer @ Vaco (2019 - 2022)

    • Built donation platform processing $1B+ annually
    • Implemented canary release management and E2E testing with Playwright
  • Software Engineer @ AT&T (2016 - 2019)

    • Led application modernization from legacy stack to React and Python
    • Built developer productivity tools integrating Jira and Bitbucket APIs

Education

B.S. Electrical Engineering - University of South Carolina

Pinned Loading

  1. tracking-number-card tracking-number-card Public

    Show Tracking Numbers from the Email Sensor for Home Assistant

    TypeScript 39 4

  2. FrigateClassifier FrigateClassifier Public

    Classify dog breeds and bird species through frigate mqtt events

    Python 25 2

  3. frigate_plate_recognizer frigate_plate_recognizer Public

    Identify license plates via Plate Recognizer and add them as sublabels to Frigate

    Python 184 22

  4. rsync-exporter rsync-exporter Public

    export rsync stats to prometheus

    Go 2

  5. tracking-numbers tracking-numbers Public

    Home Assistant tracking numbers sensor for collecting tracking numbers from over 40 providers.

    Python 8 2

  6. latchpoint/latchpoint latchpoint/latchpoint Public

    A modern, self-hosted alarm system that integrates seamlessly with Home Assistant, MQTT, Z-Wave JS, and Frigate. Build sensors, automate responses with a powerful rules engine, and stay in sync wit…

    Python 1