Maciej Starosielec · Senior Flutter developer
Mobile.Orbital.Hardened.
A decade of production Flutter. Open-source satellite tooling on pub.dev. Self-hosted infrastructure run like a mission: monitored, hardened, documented.
10+ years in mobile
2 packages on pub.dev
3 hosts under SIEM
01Commercial work
A decade in
production.
Client apps shipped as developer, architect and Flutter tech lead. Names stay under NDA - the work doesn't.
Case study · under NDA
Ten-plus years of production Flutter for international clients.
A selection of commercial apps I've helped build and scale. Most of my work is covered by NDAs, so instead of brand names, you'll find descriptions of the actual problems I solved and the tech behind them.
- Banking
- Health & coaching
- Retail e-commerce
- Sports betting
- Events
- Food delivery
02Software
Satellites,
on-device.
An open-source stack that tracks what's overhead: a pure-Dart SGP4 engine and data client on pub.dev, the AR app they power, and a Flutter Web monorepo.
Flutter · AR · on-device SGP4OrbitLens
Point your phone at the sky and see every satellite overhead, in AR or on a live world map. All SGP4 positions are computed on-device via my own Dart packages - no server, no account, works offline. Built in the EU.
Author
Flutter Web · Melos · Firebasecv-web-app
Flutter Web monorepo (Melos + pub workspaces) with two apps - a public CV site and a desktop-only admin dashboard - built on Clean Architecture with BLoC/Cubit state, GetIt + Injectable DI, auto_route, Freezed models, and a Firebase backend (Firestore, Auth, Hosting, Analytics). CI/CD via GitHub Actions with dev and prod flavors.
Author
Dart · pub.dev · TLE/OMM/SATCATCelestrak
Pure-Dart client for fetching, parsing, and caching satellite orbital data - TLE, OMM, and SATCAT metadata - from CelesTrak and Space-Track. Ships pluggable file and in-memory cache stores. No Flutter dependency; runs on any Dart platform.
Author
Dart · pub.dev · SGP4/SDP4Satellite Observer
Pure-Dart SGP4/SDP4 propagation engine: orbit propagation, topocentric look-angles, pass prediction, and naked-eye visibility windows. Zero runtime dependencies - just Dart math. The computation layer that pairs with the Celestrak data package.
Author
Python · CLI · Skyfieldsat-spotter-cli
Python CLI for satellite pass prediction. Fetches live TLEs from CelesTrak, propagates orbits with Skyfield, and prints rise/set times, max elevation, compass directions, and naked-eye visibility - with a polar sky-chart and CSV/JSON export. Built with a focus on ESA and Polish-sector satellites.
Author
Python · FastAPI · RESTsat-spotter-api
Stateless FastAPI backend serving satellite pass predictions over HTTP - the same Skyfield computation as the CLI, wrapped in a REST interface with Pydantic models. TLEs are cached on disk; no database or auth required. Designed to back a Flutter front-end.
Author
03Operations
Run like
a mission.
Self-hosted infrastructure treated as production: a SIEM with agents on every host, no public admin surface, and every non-obvious decision written down.
host hardening · firewall · VPNHardening Field Report
A systematic hardening of three hosts: SSH moved off the public internet entirely (Tailscale-only), UFW allowlists with careful Docker/iptables interaction, fail2ban as a second layer, and a patching pass that halved Wazuh's reported CVE count on the production host.
Author
detection engineering · MITRE ATT&CKWazuh SIEM
Detection engineering on a self-hosted Wazuh deployment: custom rules covering JWT brute-force chains, success-after-brute-force (MITRE T1110.004), token abuse, and Supabase auth events - plus an AI triage pipeline that turns severity 7+ alerts into a one-line verdict before they reach chat.
Author
self-hosted · Docker · CaddyAcheron Home Lab
Self-hosted home lab: GPU-accelerated local LLMs, Docker Compose stacks behind a single auto-TLS reverse proxy, a Wazuh SIEM with AI alert triage, and a Tailscale mesh that keeps every admin surface off the public internet - all documented as code.
Builder / operator
Ollama · Open WebUI · SearXNGSelf-hosted AI Stack
GPU-accelerated local LLMs (Ollama on an RTX 3080), a private chat UI (Open WebUI), and a self-hosted meta-search backend - a ChatGPT-style assistant with live web results and no queries leaving the network.
Builder / operator
Cloud VPS · CI/CD · FastAPIAethar Production
Production cloud footprint for a SaaS: FastAPI services behind Caddy, shared Postgres and Redis, isolated staging, nightly restic backups, and a self-hosted GitHub Actions runner that deploys over the private tailnet - never a public IP.
Builder / operator
04About
The short
version.
Maciej Starosielec
Senior Flutter developer
Poland
I've spent the last decade building mobile apps. My approach is simple: I translate complex business needs into clean, stable code, and I believe good architecture isn't the cleverest one, but the one that brings the fewest surprises on a Friday afternoon. When I'm off the clock, you'll usually find me messing around with open-source Dart, satellite tracking tools, or over-engineering my homelab.
I have a habit of letting my side projects get beautifully out of hand. For example, I've built a pure-Dart SGP4 propagation engine and a CelesTrak data client (both live on pub.dev), alongside an offline-first AR app that maps satellites using nothing but on-device math.
I also run my homelab like a mini enterprise production shop: Docker tucked behind Caddy, a self-hosted SIEM with agents on every host, and local LLMs running on the GPU. And yes, every single non-obvious decision is documented - because I like making future-me's life easier.
05Contact
Open
a channel.
A channel, not a contact form with an agenda. Say anything, I read it all and reply to most of it.