---
title: "Ivan Chernoknizhnikov (@treamz) | Hashnode"
description: "Ivan Chernoknizhnikov (@treamz) writes on Hashnode. Read their latest articles and follow their work."
url: "https://hashnode.com/@treamz"
---

@treamz

# Ivan Chernoknizhnikov

@treamz · Joined November 2026

### [Offline-first aquarium log in Flutter with Drift and Supabase](https://treamz.hashnode.dev/offline-first-aquarium-log-in-flutter-with-drift-and-supabase?utm_source=hashnode&utm_medium=feed)

Water tests in Flutter: blank readings that never become zero, free ammonia from pH and temperature, canonical units, Drift-to-Supabase sync.

11 min read · [treamz.hashnode.dev](https://treamz.hashnode.dev/offline-first-aquarium-log-in-flutter-with-drift-and-supabase?utm_source=hashnode&utm_medium=feed)

[2d ago](https://hashnode.com/posts/offline-first-aquarium-log-in-flutter-with-drift-and-supabase/6af5f8611460a08f22897f90)

### [Mapping free street parking from open data with PostGIS and MapKit](https://treamz.hashnode.dev/mapping-free-street-parking-from-open-data-with-postgis-and-mapkit?utm_source=hashnode&utm_medium=feed)

Turning cities' paid-parking data into likely-free kerbs with PostGIS, why OSM parking tags fail outside Germany, and drawing them in SwiftUI Map.

11 min read · [treamz.hashnode.dev](https://treamz.hashnode.dev/mapping-free-street-parking-from-open-data-with-postgis-and-mapkit?utm_source=hashnode&utm_medium=feed)

[2d ago](https://hashnode.com/posts/mapping-free-street-parking-from-open-data-with-postgis-and-mapkit/6af5f8025b27ac30aa1ef9cc)

### [Identifying card printings on device with Vision and OCR](https://treamz.hashnode.dev/identifying-card-printings-on-device-with-vision-and-ocr?utm_source=hashnode&utm_medium=feed)

Artwork matching picked the right card printing 89.5% of the time even given the number. Combining Vision feature prints with OCR, and when to ask.

11 min read · [treamz.hashnode.dev](https://treamz.hashnode.dev/identifying-card-printings-on-device-with-vision-and-ocr?utm_source=hashnode&utm_medium=feed)

[2d ago](https://hashnode.com/posts/identifying-card-printings-on-device-with-vision-and-ocr/6af5f7736946365366adf75d)

### [Planning sourdough backwards in Swift, with quiet hours](https://treamz.hashnode.dev/planning-sourdough-backwards-in-swift-with-quiet-hours?utm_source=hashnode&utm_medium=feed)

How Proofday plans a sourdough bake backwards in Swift: a temperature model, a dynamic program on a 5-minute grid, quiet hours, Live Activities.

12 min read · [treamz.hashnode.dev](https://treamz.hashnode.dev/planning-sourdough-backwards-in-swift-with-quiet-hours?utm_source=hashnode&utm_medium=feed)

[2d ago](https://hashnode.com/posts/planning-sourdough-backwards-in-swift-with-quiet-hours/6af5f7143fc81a591a875bfe)

### [Counting reps with Vision and locking apps with Screen Time](https://treamz.hashnode.dev/counting-reps-with-vision-and-locking-apps-with-screen-time?utm_source=hashnode&utm_medium=feed)

Counting push-ups from Vision body pose with one state machine, and what Screen Time's shields, callbacks and 20-activity limit really allow.

10 min read · [treamz.hashnode.dev](https://treamz.hashnode.dev/counting-reps-with-vision-and-locking-apps-with-screen-time?utm_source=hashnode&utm_medium=feed)

[2d ago](https://hashnode.com/posts/counting-reps-with-vision-and-locking-apps-with-screen-time/6af5f6b66946365366abe306)