View fastner's full-sized avatar
24 followers · 5 following

Achievements

Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor

Achievements

Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor

Organizations

@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications. Learn more about blocking users.

You must be logged in to block users.

Content in all repositories owned by your account will be closed.
Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.
Report abuse

Contact GitHub support about this user’s behavior. Learn more about reporting abuse.

Report abuse
fastner/README.md

Sebastian Fastner

React and TypeScript consultant helping product teams build and improve maintainable web applications.

Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.

Focus

  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows

Selected team work and collaborations

  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects

Contact

Project profile · Arc profile · Email

Pinned Loading

  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic

    Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript 2 1

  2. sebastian-software/palamedessebastian-software/palamedesPublic

    Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust 1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic

    Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python 1

  4. sebastian-software/standardssebastian-software/standardsPublic

    Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript

  5. sebastian-software/relantosebastian-software/relantoPublic

    Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript

  6. sebastian-software/stellarasebastian-software/stellaraPublic

    Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
View fastner's full-sized avatar
24
followers
 · 5
following

Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Achievements
Achievement: Pair Extraordinairex2Achievement: Pull Sharkx3Achievement: YOLOAchievement: Public SponsorAchievement: Arctic Code Vault Contributor
Organizations
@sebastian-software

Block or report fastner

Block user

Prevent this user from interacting with your repositories and sending you notifications.
Learn more about blocking users.


You must be logged in to block users.


Content in all repositories owned by your account will be closed.


Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.

Report abuse

Contact GitHub support about this user’s behavior.
Learn more about reporting abuse.

Report abuse
fastner/README.md
Sebastian Fastner
React and TypeScript consultant helping product teams build and improve maintainable web applications.
Available now for multi-month, fully remote projects: 40 hours/week, with collaboration across Europe and the US and overlap until 22:30 German time.
Focus
  • React, TypeScript, React Router, and Vite
  • Internationalization and accessible frontend architecture
  • Testing with Vitest and Playwright
  • Open-source tooling and AI-assisted engineering workflows
Selected team work and collaborations
  • Relanto — self-hosted transactional email infrastructure built with React and TypeScript, including scoped API access, delivery tracking, retries, and operational tooling
  • Palamedes — i18n tooling for React, TypeScript, Vite, and Next.js
  • Stellara — self-hosted TypeScript gateway for MCP clients, web research, browser automation, and vector memory
  • Effective Flow — end-to-end engineering workflows for Claude Code and Codex, from planning and implementation to review and merge
  • Sebastian Software Standards — repository automation and engineering standards
  • AI Agent Skills — reusable engineering and delivery workflows
  • Open Source at Sebastian Software — overview of current open-source projects
Contact
Project profile · Arc profile · Email

Pinned
Loading
  1. sebastian-software/eslint-config-setupsebastian-software/eslint-config-setupPublic
    
Pre-generated ESLint flat configs for TypeScript & React — 25 plugins, AI mode, OxLint-ready. One import, zero runtime overhead.

    TypeScript
2

1

  2. sebastian-software/palamedessebastian-software/palamedesPublic
    
Next-generation i18n tooling powered by OXC — fast macro transforms, message extraction, and framework adapters for Vite & Next.js

    Rust
1

  3. sebastian-software/skills.sebastian-software.comsebastian-software/skills.sebastian-software.comPublic
    
Practice-built skills that give AI agents practical judgment for product, web, engineering, delivery, go-to-market, communication, and compliance work.

    Python
1

  4. sebastian-software/standardssebastian-software/standardsPublic
    
Repository standards for the org — reference files, migration changelogs, agent instructions and a CLI to check and apply them

    TypeScript
  5. sebastian-software/relantosebastian-software/relantoPublic
    
Relanto helps teams send application emails reliably with managed SMTP configs, scoped API tokens, delivery tracking, and an admin UI for secure operations.

    TypeScript
  6. sebastian-software/stellarasebastian-software/stellaraPublic
    
Self-hosted AI tool gateway for Firecrawl, Exa, Qdrant, embeddings, browser automation, and MCP clients.

    TypeScript