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Konstantin Balzer

Beckum, Germany

Systems Architect & AI‑Augmented Engineer

Linux drivers for hardware that ships without one.

And the systems that have to keep running beside them.

View Case StudiesGitHubgithub.com/EverliteContact

  • Capture

    1440p @ 120 Hz

    Verified on a PlayStation 5.

  • Platform

    15+ people

    Internal tool, in production.

  • Analytics

    No cookies

    Hits stay on the operator's server.

Faster with models. The decisions stay mine.

I use them for architecture, prototypes, and kernel traces. Security review, pipelines, and what ships stay with me.

Case studies

01

EverLive

Native Linux Driver for AVerMedia GC573 · C, V4L2, PCIe DMA, PipeWire, SDL2

github.com/Everlite/EverLive

Problem

AVerMedia had not shipped a Linux driver for their GC573 flagship capture card in over 7 years. The proprietary binary blob (aver_xilinx.o) failed on cold-boot states,DMA transfers delivered only black frames (0x10 0x80 YUYV pattern), and audio streams drifted into XRUNs within minutes due to clock jitter.

aver_xilinx.o: cold-boot, GPIO reset missing
dma: YUYV 0x10 0x80 — black frames
pipewire: XRUN, clock jitter, 48 kHz
Failure mode of the vendor blob on Linux, before open_gc573.

Engineering solution

  • Hardware reverse engineering

    Disassembled the vendor blob to extract cold-boot GPIO reset sequences for the IT6664 HDMI splitter and IT6805 receiver. Implemented I2C bus initialization and FPGA validators for native Artix-7 DMA ringbuffers.

  • Edge-case timing and FPGA pipelines

    Extended V4L2 mode tables and FPGA validators for anamorphic signals (3840x1080@120Hz with 2x vertical stretch) and CRT Super-Res (1920x240p in dual-pixel DDR mode).

  • Audio subsystem

    Analyzed hardware clock drift between the capture card oscillator and the host sound card. Integrated PipeWire's delay-locked loop resampler (pw-loopback) to remove buffer underruns and audio pops at 48kHz/10ms latency over 24/7 sessions.

  • Live HDR10 and colorimetry switching

    Hot-swapping FPGA color space converter matrices during active DMA streams without triggering VIP resets.

  • Community support

    Full compatibility across Arch/CachyOS, Fedora, and Ubuntu/Mint. Automated cross-distro installer with DKMS support for kernel updates.

Result

A GPL-2.0 kernel driver and low-latency C/SDL2 display renderer (1–2ms hardware latency) that outperforms the official Windows driver in latency, feature set (native Wayland, HDR live-switching), and stability. 26 GitHub stars, in use by the retro-gaming and streaming community.

open_gc573 · load
~/Avermedia-GC573-Linux main
❯ sudo ./open_gc573/load.sh
[*] Checking loaded modules and unloading them…
[*] Loading kernel dependencies (v4l2-dv-timings, videobuf2, …)…
[*] Loading open_gc573 (open_gc573.ko)…
[+] open_gc573 loaded
[*] Waiting for HDMI signal lock (max. 5s)…
[+] Signal locked on /dev/video2

=== PCI driver binding ===
0a:00.0 Multimedia video controller: Avermedia Technologies Inc Device 0054
        Subsystem: Avermedia Technologies Inc Device 5730
        Kernel driver in use: open_gc573
        Kernel modules: open_gc573

=== Kernel messages ===
[16016.172546] open_gc573 0000:0a:00.0: registered multicolor LED device 'gc573:rgb:status'
[16021.866601] open_gc573 0000:0a:00.0: registered video2
[16021.866641] open_gc573 0000:0a:00.0: hardware transport, HDMI chips, and capture endpoints initialized
[16113.096854] open_gc573 0000:0a:00.0: IT6664 fixed upstream EDID published checksums=11/ff

=== V4L2 devices ===
AVerMedia Live Gamer 4K GC573 (PCI:0000:0a:00.0):
        /dev/video2

~/Avermedia-GC573-Linux main 16s

A load with the HDMI signal locked.

02

Internal platform

Internal operations platform · Next.js 16, React 19, PostgreSQL/PostGIS, Docker, Python

Problem

An internal team needed a paper process replaced by a system that works offline, turns incoming PDFs into records, and stays GDPR-compliant.

Engineering solution

  • Offline-first PWA

    IndexedDB form caching and an outbox pattern for offline use. Digital signatures and photo uploads, including client-side HEIC conversion and compression, sync when connectivity is available.

  • Automated backend pipelines

    A Python file watcher (pdfplumber) parses incoming PDFs, imports them through a secured API (internal API key, Nginx isolation), and prevents race conditions with reconcile loops.

  • Security and compliance

    Grey-box pentest, role-based access control, GDPR data retention (purge scripts), and a 3-tier backup strategy (VPS → rclone/OneDrive → NAS).

  • Geo integration

    PostGIS for positions. Geoapify, Photon, and Overpass as a fallback chain for address autocomplete. Valhalla for routing.

  • Shared screen

    A dedicated read-only role for a shared screen that shows the current overview.

Result

In production with 15+ users. Paper forms are gone, and positions update throughPostGIS. Solo-architected and delivered with full GDPR compliance (AV contracts, VVT documentation).

03

Spectora

Privacy-by-design observability suite · Laravel, Docker, SQLite/PostgreSQL, Tailwind

github.com/Everlite/Spectora-Website-Monitoring-Suite

Problem

Web agencies serving GDPR-sensitive European clients need monitoring tools that don't send data to US servers. Existing SaaS solutions fail strict compliance audits.

Engineering solution

  • DevSecOps and SSRF prevention

    Double-layered SSRF protection, DNS pinning, and heuristic malware scanning (eval obfuscation, CJK SEO spam) in the SpectoraWatchdogEngine kernel.

  • Cookie-free analytics

    PulseIngestEngine with rotating HMAC-SHA256 visitor subkeys and origin validation. No raw IPs stored. Third-party trackers are rejected.

  • Pivot to open source

    Restructured from a multi-tenant SaaS architecture to a single-tenant on-premise appliance for agencies.

  • Production-ready

    Docker Compose deployment, queue workers via Supervisor, scheduler heartbeats, and a runbook plus privacy documentation.

Result

An open-source B2B monitoring platform for European agencies that require strict GDPR compliance. A self-hosted alternative to Datadog and UptimeRobot, with the data staying on the operator's server.

04

PS5-to-Steam Bridge

Cross-platform presence bridge · Python, Node.js, Tkinter

github.com/Everlite/PS5-to-Steam-Bridge

Problem

Steam shows friends what you're playing on Steam — but not what you're playing on PS5. That is a feature gap between the platforms.

Engineering solution

  • Cross-platform packaging

    Windows ships as one EXE with Node embedded and no Python install for the recipient. Linux runs from source, with the steps written down.

  • Token storage

    DPAPI encryption for tokens on Windows, an encrypted secrets.bin, and a migration off plaintext config. The repository warns against committing secrets.

  • Edge cases

    The app documents the behavior people misread: friends seeing you come online is expected, status is cleared on quit, and Steam's Invisible or Offline state gets overwritten while the bridge is running.

Result

A small cross-platform tool, built to close a personal gap, finished to the point that tokens, quit-cleanup, and the Windows package behave like a product.

Open source

  • EverLive

    26 stars

    Blob-free Linux driver and capture path for the AVerMedia GC573.

  • Spectora

    1 star

    Self-hosted monitoring and cookie-free analytics for one agency server.

  • PS5-to-Steam Bridge

    2 stars

    Shows the current PlayStation 5 game on a Steam profile.

Remote and contract.

Beckum, Germany