hjanuschka@terminal:~$

Helmut Januschka

Head of Engineering @krone.at • Open Source Contributor

25+ years experience Currently @krone.at Vienna, Austria
Blog
In Progress
ONGOING
August 2026

Making Installed Web Apps Belong on the OS

System bars, cutouts, IME insets, and toolbar seams - verified by a reproducible nine-case Android hardware matrix.

IN REVIEW
August 2026

Fixing CSS Zoom and Explicit Inheritance

Why inherit, unset, and revert-layer need to cross zoom boundaries without double-scaling computed lengths.

IN REVIEW
August 2026

What the Browser Sees Before the Parser

Teaching the preload scanner to notice speculation rules early without turning it into a second HTML parser.

ONGOING
August 2026

JPEG XL, One Year Later

ClusterFuzzLite, Chromium fuzzers, thread-schedule testing, progressive rendering, and the hardening after integration.

ONGOING
August 2026

Shrinking Chromium's Binary, One Table at a Time

About 567 KiB of measured arm64 savings from replacing generated control flow with compact data tables.

IN REVIEW
August 2026

Another Try at Bringing HTTPS-RR to Chrome

Take two on RFC 9460: AliasMode, ServiceMode target names, hints and ports - five small ordered CLs.

APP STORE REVIEW
August 2026

Building sesh: SSH and zellij, Native on iOS

Why mobile SSH needs more than a scaled-down terminal, and how sesh turns remote zellij workspaces into native touch UI.

IN REVIEW
August 2026

Web Bluetooth: How Large Can a Write Be?

Exposing maxWriteWithoutResponseSize so pages can use the negotiated connection instead of assuming a 20-byte payload.

IN REVIEW
February 2026

Camera Capture on Desktop

Bringing <input type=file capture> to Windows, Mac, and Linux. Closing a 12-year-old feature gap.

ONGOING
February 2026

Reviving Old Ideas: clang-tidy for LLVM

Invest in tooling once, reap the benefits forever. ~2,000 Chromium cleanups from a few checks.

Landed
LANDED
August 2026

Four Dangling Pointers, One Ownership Lesson

Using declaration and teardown order to make raw_ptr observers die before the objects they do not own.

LANDED
August 2026

Implementing text-decoration-inset in Blink

Making underlines stop short of the text edges, from CSS parsing through inline fragments and painting.

LANDED
August 2026

Fixing the DevTools Friction I Kept Running Into

Binary payloads, storage clearing, XML documents, hidden columns, and flame-chart search.

LANDED
August 2026

Deleting base::TimeTicks::UnixEpoch

Removing a misleading conversion between monotonic ticks and wall-clock time, one subsystem at a time.

LANDED
July 2026

Cancelling a Pending Web Bluetooth Connection

Making disconnect() finish an in-flight connect exactly once on Windows and Android, with an AOSP detour.

LANDED
July 2026

Touch Drag-and-Drop on Linux

Long-press drag now works on Linux instead of popping the context menu, matching Windows. Enabled by default.

LANDED
July 2026

Edge-to-Edge for Fullscreen PWAs

Installed fullscreen PWAs on Android now draw under the notch via short-edges cutout mode. Available in Canary.

LANDED
July 2026

Preserving Focus Across the Back-Forward Cache

Pages restored from BFCache now come back with the same element focused - with the IME state kept in sync.

LANDED
July 2026

Debugging Android's VirtualKeyboard Geometry

Three CLs against one moving target: keyboard insets, innerHeight overshoot and undershoot during animations.

LANDED
June 2026

Moving Data Out of the Chrome Binary

USB ID database and libphonenumber metadata: compressed, lazily loaded, and finally enabled on Android.

LANDED
June 2026

DevTools: CSS Specificity Breakdown

The selector tooltip now shows which parts of a selector contribute to each specificity component, computed by Blink itself.

LANDED
May 2026

Ctrl+Alt+Click: Links in Split View

Adding a new WindowOpenDisposition through Blink, content and chrome - including the renderer-kill bug along the way.

SHIPPED
May 2026

Shipping Request.isReloadNavigation

A fetch API attribute for service workers, from implementation through Intent to Ship to enabled-by-default.

LANDED
January 2026

Fixing a 3.5-Year-Old Race Condition

Pseudonymization salt via shared memory. When the bug report is older than some interns.

LANDED
January 2026

DevTools: Speculation Rules Filter

Adding text filtering to Chrome's Speculation Rules panel after real-world testing at krone.at.

LANDED
December 2025

Lazy Loading for Video & Audio

Implementing loading="lazy" for media elements. Cross-browser collaboration with Squarespace.

LANDED
November 2025

JPEG XL Returns to Chrome

From "obsolete" in 2022 to welcomed back in 2025. Rust implementation within 4% of C++ performance.

LANDED
October 2025

From Tweet to Chrome: Tab Focus

A tweet from Tobi Lütke led to --focus flag. Focus existing tabs instead of creating duplicates.

LANDED
September 2025

Dynamic Chrome Themes for Omarchy

DHH needed CLI theming for Omarchy Linux. CLI switches for Material Design themes in record time.

LANDED
August 2025

Wayland Crash: Community Debugging

Chrome crashing on multi-monitor Wayland. Bug report to upstream fix in 72 hours.

Tools & Workflow
TOOLS
June 2026

Packaging a Custom Chromium Build

Turning a patched dev build into a distributable .deb/.rpm, universal .app, or mini_installer.

TOOLS
July 2025

Why I Switched to Pi

Terminal-first coding agent. Multi-model switching, session trees, extensible hooks.

Experiments
EXPERIMENT
February 2026

JPEG XL in PDF via PDFium

Experimental JXL-in-PDF decoding using jxl-rs. Alpha via synthesized /SMask, animation → frame 0.

Shelved
STOPPED
January 2026

Fixing AV1 Hardware Encoding on AMD/Mesa

Deep dive into DPB management: fixing GPU crashes for WebRTC video calls. Work stopped; see the tracking bug.

REJECTED
February 2026

Reviving HEv3 & HTTPS-RR in Chromium

Pursuing RFC 9460 support in Chrome. Rejected in favor of the team's ongoing network-stack refactor.

About

I work as Head of Engineering at krone.at, focusing on engineering management, technical strategy, and system reliability. My background spans 25+ years across various technology domains.

I contribute to open source projects including Chromium, LLVM, PDFium, and Fastlane. Areas of interest include system performance, developer tooling, and infrastructure automation.

Current Roles

👔 Head of Engineering @krone.at
🏢 CEO & CTO @Captcha.eu
🚀 Founder & CEO RunUntil Technologies GesmbH
🌐 Chromium Committer
🛠️ Breaking browsers with C++
Experience & Focus

Engineering Leadership

Leading technical vision and engineering teams at scale. Experience building and maintaining systems that serve millions of users.

System Architecture

25+ years across the full technology stack - from low-level system programming to distributed cloud architectures.

Open Source Philosophy

Active contributor to major projects. Building tools that make developers more productive.

Entrepreneurship

Founded and leading Captcha.eu - a GDPR-compliant bot protection service hosted in Austria. Serves clients including ÖBB, Bauer Media Group, and E.ON with privacy-first, accessible web security solutions.

Current Stack @krone.at
• Multi-language web applications
• Kubernetes container orchestration
• Varnish + CDN for caching & optimization
• Legacy print CMS to digital publishing migration
• In-house mobile app development teams
• TV broadcast technology integration
• Real-time content delivery pipelines
• High-availability database clusters
• CI/CD & infrastructure automation
Open Source Contributions

Chromium

Chromium Committer. Key contributions include reviving JPEG XL support with a Rust decoder, the --focus flag for tab reuse, dynamic theming for Omarchy, and fixing long-standing bugs in tracing, DevTools, and media encoding.

LLVM Project

Enhanced clang-tidy modernization tools by implementing pattern detection for substr() operations that can be replaced with C++20 starts_with() method, improving code readability and performance.

Fastlane

Key contributor to iOS and Android deployment automation tool. Enhanced Spaceship module for App Store Connect integration, improved terminal responsiveness, and fixed critical build system compatibility issues.

Composer

Contributed to PHP's dependency manager. Implemented GitLab API v4 pagination support for repository discovery and improved tag/branch collection functionality for better package resolution.

VibeTunnel

Browser-based terminal multiplexer for frictionless remote access to macOS terminals. Designed for "vibe coding" - maintaining developer flow from anywhere. Core contributor to this innovative tool for monitoring AI agents and remote development.

Omarchy Chromium Micro Fork

When DHH called out for help with live theming in Chromium for his Omarchy Linux distribution, I answered the challenge. Now maintaining a micro fork that enables dynamic theme switching without browser restart. Working to upstream this patch while providing the feature to the Omarchy community through an AUR package.

Get In Touch

I'm always interested in discussing new projects, opportunities, or just chatting about technology.

Online

GitHub: hjanuschka
LinkedIn: in/hjanuschka
Twitter: @hjanuschka

Direct

Location: Vienna, Austria
Timezone: UTC+1
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