senn-techNotes & deep dives.
Hands-on articles on AI integration, cloud, performance and engineering.
- Infrastructure2026-07-06
SSO for the Self-Hosted Stack: Authentik and Keycloak Compared
Nextcloud, Gitea, Zammad, mail, chat — each tool brings its own login. A central identity provider ends that, cuts the password chaos, and is the foundation for MFA. Authentik and Keycloak are the two serious open-source options.
Read more → - Strategy2026-07-06
Sovereign AI: Data Sovereignty Is an Architecture Decision, Not a Mood
“Sovereign AI” has become fashionable — often as a marketing label. Real data sovereignty does not come from an EU badge, but from an architecture in which the AI's data never leaves the building. What that means technically, and where the limits are.
Read more → - Security2026-07-06
NIS2 and DORA: What a Self-Hosted Stack Must Actually Deliver
NIS2 applies to many mid-sized companies, DORA to financial services. Both demand less a specific product than a provable process. What a Proxmox, backup, and mail stack contributes on-prem — and what it does not replace.
Read more → - Strategy2026-07-06
Email Archiving: GoBD-Compliant, On-Premises, No Lock-in
Business emails are commercial records — six years of GoBD retention, immutable, searchable, audit-proof. Why we don't outsource that to the cloud, but run Open Archiver on our own hardware instead.
Read more → - AI & Development2026-06-29
One RTX 5090 Instead of Four Old GPUs: Consolidating Vision Inference
For the image and PDF stage of our extraction pipeline, we replaced four older accelerators with a single RTX 5090. Why one current card beats four old ones here — and what the real root cause was.
Read more → - AI News2026-06-29
AI Radar: Qwen 3.6 — Alibaba's Open Middle Path
Alibaba keeps the smaller Qwen models open while closing the flagship. Why the Apache-licensed 3.6 line is the interesting part for self-hosting — and where the catch is.
Read more → - AI News2026-06-29
AI Radar: NVIDIA Nemotron 3 — Open Down to the Training Data
NVIDIA follows up with the Nemotron 3 family: Nano, Super, and Ultra — and releases not just the weights, but the training data, RL environments, and recipes. Why that matters more for self-hosting than a benchmark point.
Read more → - AI News2026-06-29
AI Radar: Mistral Small 4 & Voxtral — Europe's Open Answer
Mistral folds reasoning, multimodality, and coding into one compact Apache model — and enters the voice race with Voxtral. Where Europe's AI lab shines for self-hosting, and where the license slows you down.
Read more → - AI News2026-06-29
AI Radar: Meta Llama 4 — Multimodal, Open, With Fine Print
Llama 4 brings mixture-of-experts and native multimodality to the most widely used open model ecosystem. Why that's strong — and why European companies especially should read the license closely.
Read more → - AI News2026-06-29
AI Radar: xAI Grok 4.3 — Fast, Closed, Frontier
Grok gets faster, multimodal, and multi-agent capable — but stays closed and tightly bound to X. Why we watch it without putting it on our self-hosting path.
Read more → - AI News2026-06-29
AI Radar: Gemini 3.5 Flash & Gemma 4 — Fast in the Cloud, Open at Home
Google ships two models: the fast, closed Gemini 3.5 Flash for agentic workflows and the open Gemma 4 for self-hosting. The split between cloud speed and data sovereignty, seen from both sides.
Read more → - Security2026-06-29
Agentjacking: When an Error Report Hijacks Your AI Agent
A new attack class smuggles malicious commands into AI coding agents through tool output such as error reports. How it works — and which guardrails actually help in an SME.
Read more → - AI & Development2026-06-23
Making Self-Hosted AI Faster: Speculative Decoding and dFlash
Self-hosted inference is decode-bound, not compute-bound. Speculative decoding fixes that without touching output quality — and NVIDIA's new open dFlash drafter pushes it further. What it is, the numbers, and what it means for our own GPUs.
Read more → - Infrastructure2026-06-19
From Pi-hole to Technitium: One Server for Blocking, DNSSEC and Native HA
We ran Pi-hole v6 in production — until high availability became the breaking point. Why we migrated both resolvers to Technitium DNS Server: native clustering, DNSSEC validation, encrypted upstream (DoT) and advanced blocking in a single engine.
Read more → - Storage2026-06-16
TrueNAS as a File Server Replacement: ZFS Instead of Windows File Server
The classic Windows file server has had its day. TrueNAS brings ZFS, snapshots and replication — without license costs and with greater data security. An experience report from the migration, including pool layout, "Previous Versions" and AD integration.
Read more → - AI News2026-06-15
AI Radar: MiniMax M3 — Open-Weight with Million-Token Context
MiniMax follows up with M3: open weights, a million-token context, and a new efficient attention. Why this is exciting for context-heavy tasks on self-hosted hardware.
Read more → - AI News2026-06-15
KI-Radar: Kimi K2.7 Code — One Trillion Parameters, Open, and the Catch in the Benchmarks
Moonshot AI brings Kimi K2.7 Code: one trillion parameters, open weights, 256K context — and a fraction of the price of Claude Opus. We examine whether the model holds up in daily use and where the catch in the benchmarks lies.
Read more → - AI News2026-06-15
KI-Radar: z.ai GLM 5.2 — the Coding Specialist from China
Zhipu (z.ai) releases GLM 5.2: coding-first, one-million-token context, and open weights under MIT license. What this means for development teams and self-hosting.
Read more → - Security2026-06-11
Proxmox Mail Gateway 9.1: Smarter Quarantine, Encrypted Backups
Proxmox Mail Gateway 9.1 improves spam quarantine for shared mailboxes, loads external images in HTML emails only on request, and encrypts backups client-side — based on Debian 13, SpamAssassin 4, and ClamAV.
Read more → - AI News2026-06-09
AI Radar: Claude Fable 5 and Mythos 5
Anthropic splits its new top tier into two: Fable 5 for everyone, Mythos 5 only for vetted partners. What lies behind the model — and what SMEs should watch for.
Read more → - Security2026-06-02
Security Awareness for SMEs: The Human as the Smartest Link
Technology alone does not protect — the best spam filter is useless if someone clicks the link. Why security awareness is not a mandatory lecture, but a continuous process that can be enjoyable.
Read more → - Strategy2026-06-02
Secure Communication: Matrix/Element vs. Microsoft Teams
Federated, self-hosted chat protocol or SaaS platform? Matrix and Element offer end-to-end encryption and data sovereignty — Microsoft Teams provides the convenience of an integrated suite. A comparison in depth.
Read more → - AI News2026-05-28
KI-Radar: MiniMax — the underestimated challenger
MiniMax is still little-known in the DACH region, but delivers open models with very long context. A look at a provider worth keeping on the radar.
Read more → - Infrastructure2026-05-21
Proxmox VE 9.2: Dynamic Load Balancer for the Cluster
With version 9.2, Proxmox VE gains a dynamic load balancer that automatically distributes running VMs across the cluster — building on the 9.0 generation with Debian 13, new storage features, and SDN fabrics.
Read more → - Security2026-05-19
Patch Management Without SCCM: Updates in SME Daily Operations
Patching is annoying until a vulnerability is exploited. How we automatically keep Linux VMs, Docker containers, and Proxmox hosts up to date — without tools that require their own budget.
Read more → - Strategy2026-05-19
Files & Collaboration: Nextcloud vs. OpenCloud
Nextcloud has dominated the self-hosted market for years. OpenCloud re-enters with Go and oCIS. An honest comparison: when the incumbent, when the challenger is the better choice.
Read more → - AI News2026-05-06
AI Radar: Anthropic's Claude-4 Family (Opus, Sonnet, Haiku)
Anthropic's current Claude generation covers three sizes: Opus for heavy lifting, Sonnet for everyday use, Haiku for speed and cost. What this means for the SME.
Read more → - Strategy2026-05-05
Helpdesk in-house: Zammad as a Ticket System
A helpdesk that turns emails into tickets and does more than Outlook rules. Zammad in-house: setup, SLA management, knowledge base, and the difference from SaaS providers.
Read more → - Strategy2026-05-05
Documentation-as-Code: Wiki.js, BookStack or Markdown in Git?
Internal documentation usually fails at the hurdle of writing. Markdown in Git reduces this hurdle to zero — and an agent that already writes code documents along the way.
Read more → - Infrastructure2026-04-30
Proxmox Backup Server 4.2: S3 Object Storage and Parallel Sync Jobs
Proxmox Backup Server 4.2 brings official S3-compatible object storage as a backend, parallel sync jobs, and server-side encryption of replication — based on Debian 13, Kernel 7.0, and ZFS 2.4.
Read more → - Infrastructure2026-04-21
WireGuard: VPN for Everyday Use
WireGuard is fast, simple, and in the Linux kernel. How we build site-to-site and road-warrior VPNs with it, what to watch for with NAT and MTU — and why it replaces IPsec and OpenVPN in almost every SME scenario.
Read more → - Infrastructure2026-04-21
Monitoring without the baggage: Uptime Kuma in-house
Uptime Kuma brings status monitoring, notifications, and a public status page in one Docker container. What the tool does, how we use it, and where its limits lie.
Read more → - AI News2026-04-10
AI Radar: Google Gemini
Google's current Gemini generation scores with a huge context window and native multimodality — and is deeply integrated into Google Workspace. Strengths and stumbling blocks.
Read more → - Infrastructure2026-04-07
DNS Adblocking Self-Hosted: Pi-hole vs. AdGuard Home
Block ads and tracking network-wide — without browser plugins. Pi-hole (v6) and AdGuard Home compared: setup, DoH/DoT, recursive DNS with unbound, redundancy, and everyday usability.
Read more → - Infrastructure2026-04-07
Git In-House: Gitea and Forgejo
Source code does not belong on foreign servers. Gitea and Forgejo bring GitHub functionality to your own network — CI/CD, Issues, Pull Requests, Actions. Lightweight, open source, ready to deploy in 20 minutes.
Read more → - AI & Development2026-03-20
Codex, Gemini CLI & Co: The Agent Landscape 2026
Claude Code, OpenAI Codex, Google Gemini CLI — the most important agentic coding tools at a glance. Strengths, differences, and why we take a multi-track approach.
Read more → - AI News2026-03-18
AI Radar: GPT-5 from OpenAI
OpenAI's current generation sets new standards in reasoning and multimodality — and remains for many the easiest entry point. What companies should consider.
Read more → - Infrastructure2026-03-17
Docker vs. LXC in Proxmox: When to Use What?
Docker containers or LXC? This question arises for every Proxmox operator. Both have their place — but for different use cases. A practical decision guide, including unprivileged containers and the Docker-in-LXC pitfall.
Read more → - Infrastructure2026-03-03
Reverse Proxy with Caddy: HTTPS by Default
Caddy makes reverse proxying easy — automatic HTTPS, HTTP/3, no certificate headaches, one configuration file. How we secure internal services and make them publicly available.
Read more → - AI News2026-02-20
KI-Radar: DeepSeek — From R1 to the V4 Series
DeepSeek has made waves with open weights and strong reasoning. Why the models are technically interesting — and why the hosting location needs careful scrutiny.
Read more → - Security2026-02-20
Intrusion Prevention: CrowdSec instead of fail2ban
fail2ban is yesterday. CrowdSec shares threat data across all participants and blocks attackers before they reach your services. Modern, open source and NIS2-compliant to operate.
Read more → 
AI & Development2026-02-12Claude Code in Practical Use
Anthropic's agentic coding assistant in real project life: What we use Claude Code for, how Skills, MCP servers, and subagents work together — and where the limits lie.
Read more →- Infrastructure2026-02-06
3-2-1 Backup Strategy with Proxmox Backup Server
Backups only matter when they're missing. Proxmox Backup Server, ZFS snapshots, and a Hetzner Storage Box form a 3-2-1-1-0 strategy that is NIS2-compliant and field-proven.
Read more → - Infrastructure2026-01-15
Proxmox HA Cluster: Quorum, Fencing and the End of Single-Host Woes
A single Proxmox host is fine—until it fails. Then everything stops. A three-node HA cluster with Ceph storage is better. What the setup truly requires, why a QDevice solves the two-node problem, and why fencing is no optional detail.
Read more → 
AI & Development2026-01-15Agentic Coding: How AI Agents Transform the Dev Daily Routine
From autocomplete to autonomous agent: What 'agentic coding' really means, where it works today and where human judgment remains indispensable.
Read more →- AI & Development2026-01-01
Email AI: Classification, Routing, and Reply Suggestions Locally
Automatically classify emails, route to the right handler, and generate reply suggestions — with local LLM, n8n, and own mail infrastructure. Productive, not futuristic.
Read more → - Strategy2025-12-18
PDF-Workflows: Automatically ingest incoming invoices into ERP
Incoming invoices via email in, classified into ERP out — without manual data entry. How Paperless-ngx, n8n and a local LLM turn PDFs into structured data and why it must be on-prem.
Read more → - Strategy2025-12-04
Translogica TMS: Transport-Management on-prem
Transportation Management Systems are the backbone of logistics. Translogica on-prem gives us control over routes, shipments, and integrations — without cloud dependency in daily operations.
Read more → - Strategy2025-11-20
Winline ERP In-House: Why We Don't Move Core Software to the Cloud
ERP systems contain a company's most sensitive data. Winline on-prem on our own SQL server gives us full control — over data, customization, and integrations.
Read more → - AI & Development2025-11-06
MCP-Server in-house: Agents with their own knowledge fed
Model Context Protocol gives coding agents tools — but the most valuable MCP servers are those with their own knowledge: internal docs, ERP data, TMS status. So we build them ourselves.
Read more → - Infrastructure2025-10-16
Hosting at Hetzner: Root-Servers and Colocation as the Middle Ground
Cloud is expensive, maintaining your own server room is cumbersome. Hetzner offers root servers and colocation as a middle ground: your own hardware, someone else's power, full control. What makes sense and how we use it.
Read more → 
Storage2025-10-14Storage Journey, Part 3: Arrived at DRBD & LINSTOR
Shared-nothing block-level replication, live-migratable VMs without central SAN and commercial support path. Why DRBD/LINSTOR is the right storage foundation for us.
Read more →- Strategy2025-10-02
Cloud vs. On-Prem: The Honest Calculation 2027
Cloud is not an end in itself and on-premises is not nostalgia. The decision depends on workload, cost structure, and compliance — and it turns out differently in 2027 than it did just five years ago.
Read more → - AI & Development2025-09-16
EU AI Act: Why Local AI Is the Right Answer
The EU AI Act regulates AI applications by risk class — and makes locally operated models the strategically cleanest option. What the law requires and why owning your hardware simplifies compliance.
Read more → - Security2025-09-02
NIS2 and Self-Operation: Compliance through Control
NIS2 obligates more companies to cybersecurity measures than many realize — and places personal responsibility on management. Why self-hosting and self-operation simplify implementation.
Read more → - AI & Development2025-08-19
AI Phone Agents: Voice Bots with Pipecat & Asterisk
Real-time voice pipeline — STT, LLM, TTS — connected to a phone system: Pipecat and Asterisk make it possible. A look at what works today and where the limits lie.
Read more → - Infrastructure2025-08-05
VoIP & Telephony with innovaphone — on-prem instead of Cloud-PBX
Telephony does not need to move to the cloud. Innovaphone brings IP-PBX, SIP trunks, and device management into your own rack. A field report on setup, high availability, and integration.
Read more → - AI & Development2025-07-15
Workflow Automation with n8n — Self-Hosted
n8n connects services, webhooks, and now also AI agents in a self-hosted workflow tool. What sets n8n apart from Zapier and Make — and why we use it for serious automation.
Read more → - Storage2025-07-09
Storage Journey, Part 2: Vitastor — fast, but young
Vitastor promises Ceph-like architecture at significantly lower latency. What we observed in operation — and why 'fast' alone isn't enough.
Read more → - Strategy2025-07-01
Business Intelligence self-hosted: Metabase
Dashboards on your own databases, no SQL knowledge needed, no cloud subscription. Metabase brings BI in-house — and makes querying your own data as easy as Googling.
Read more → - AI & Development2025-06-17
RAG Environments Compared: Vector Databases, Chunking, Embeddings
Retrieval-Augmented Generation promises facts from your own documents — but the pipeline behind it decides the quality. Vector databases, chunking strategies, and embedding models in a practical check.
Read more → - AI & Development2025-06-03
LLM Frontends: OpenWebUI vs. LibreChat
Two self-hosted web interfaces that turn local LLMs into a usable chat service. OpenWebUI and LibreChat compared: multi-model, RAG, user management, everyday usability.
Read more → 
Strategy2025-05-20Self-Hosting as a Strategy: Data Sovereignty Instead of Cloud Dependence
Self-hosting is not a hobbyist romance, but an economic and legal decision. When own hardware surpasses the cloud — and when it does not.
Read more →- AI & Development2025-05-20
llama.cpp & GGUF: LLMs locally, efficiently, without a cluster
llama.cpp enables LLM inference on consumer hardware — quantization, CPU/GPU offload, and a file format that needs no cloud budget. The counterpoint to vLLM and when to use which tool.
Read more → - AI & Development2025-05-06
High-Throughput LLM Inference with vLLM on Custom Hardware
vLLM makes LLM inference fast and efficient — PagedAttention, continuous batching, and an OpenAI-compatible API. Here's how we run it on an RTX 5090 and what really matters.
Read more → - Storage2025-04-22
Storage Journey, Part 1: What Ceph Taught Us
Ceph is the Swiss Army knife of distributed storage — powerful, but hungry. Why we started with it, what hardware it really demands, and where it hit limits for our cluster size.
Read more → - Infrastructure2025-04-15
Network Basics: VLANs & Jumbo Frames
802.1Q segmentation and MTU 9000 are not just details for network enthusiasts, but solid tools for more security and throughput. When they help, how Proxmox SDN manages them — and where they cause harm.
Read more → - Infrastructure2025-04-01
Server OS Choice: Ubuntu vs. Alpine
Ubuntu brings stability and support, Alpine minimal image size and musl. When each server OS makes sense — and why the question looks different in the container era than it did five years ago.
Read more → - Infrastructure2025-03-18
SQL Server 2022/2025 Self-Hosted — Not Just on Windows
SQL Server has long run stably on Linux and in containers. What versions 2022 and 2025 bring, how backup and high availability look in self-hosted operation — and what licensing costs.
Read more → - Security2025-03-04
Single Sign-On & IAM: Keycloak Secures Internal Services
One login for all internal services — Keycloak makes it happen without licensing costs. OIDC, SAML, Identity Brokering, and MFA for web applications behind the reverse proxy. Here's how we use it.
Read more → - Security2025-02-21
Mail Security: NoSpamProxy in front of your own mail server
Spam, malware and missing encryption are the three persistent problems of email. NoSpamProxy solves all three as a gateway in front of your own mail server — and brings S/MIME with it.
Read more → - Infrastructure2025-02-18
From VMware to Proxmox: Why We Switched Hypervisors
Licensing costs, uncertainty after Broadcom's acquisition, and the desire for true data sovereignty: why we migrated our virtualization to Proxmox VE — including native ESXi import, VirtIO pitfalls with Windows, and a clean cutover.
Read more → - Infrastructure2025-02-07
Self-Hosted Mail Server: Stalwart & Axigen vs. Exchange
Exchange is expensive and complex. Modern self-hosted alternatives like Stalwart and Axigen offer JMAP, IMAP, and SMTP at a fraction of the complexity. What they deliver, where the differences lie.
Read more → 
Innovation2024-12-10AI Integration in Enterprise Environments: Strategy for Sustainable Innovation
Artificial intelligence has become a competitive factor. How to successfully, securely, and sustainably embed AI in the company — from data foundation to productive operation.
Read more →- Cloud Solutions2024-12-01
Cloud Migration Best Practices: Enterprise-Grade Strategies
From countless migration projects: the 6-phase strategy that determines success or costly failure — from inventory assessment to operational optimization.
Read more → - Web Development2024-11-15
PHP 8 Performance: Achieve noticeable speed gains
JIT, OPcache and Preloading properly configured — how to turn an average PHP application into a fast one without rewriting the code.
Read more →