Software developer, team lead, and trainer who thrives in a diverse IT environment, combining DevOps, AI, and creativity to build software, books, and music.https://bsky.app/profile/dominiksigmund.bsky.socialhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3muraaaevk32aThree AI agents agree. Great—unless they all used the same bad evidence. The new article looks at false consensus, correlated failures, reviewers, conflict tests, provenance, and why multi-agent agreement is not truth. https://amzn.eu/d/0blIkveq #AIAgents #MultiAgent https://webdad.eu/2026/09/05/when-three-ai-agents-agree-and-are-still-wrong/05 Sep 2026 10:07 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3muraaaevk32ahttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mu546jxect2xA tool timeout does NOT mean the write failed. If the agent retries blindly, it may execute the same action twice. This article covers idempotency, reconciliation, uncertain state, failure injection, and duplicate-write tests. https://amzn.eu/d/0blIkveq #AIAgents #SoftwareTesting https://webdad.eu/2026/08/28/the-tool-timed-out-did-the-agent-just-do-it-twice/28 Aug 2026 10:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mu546jxect2xhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mtlivxktxa2xOne prompt cleanup. Better latency. Lower cost. Higher pass rate. And 12 new failures. The second article shows why aggregate scores can hide dangerous AI agent regressions—and how severity gates catch them before release. https://amzn.eu/d/0blIkveq #AIAgents #LLMEvaluation https://webdad.eu/2026/08/21/one-prompt-change-twelve-new-failures/21 Aug 2026 10:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mtlivxktxa2xhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mszvoex4lz2kA tool failure is obvious. Bad retrieval can be much quieter. The agent finds a plausible document, produces a grounded answer—and is confidently wrong. From The AI Agent Test Manual:https://amzn.eu/d/0blIkveq #AIAgents #RAG #LLMEvaluation #SoftwareTesting https://webdad.eu/2026/08/14/the-agent-was-confident-the-data-was-wrong/14 Aug 2026 10:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mszvoex4lz2khttps://bsky.app/profile/dominiksigmund.bsky.social/post/3msfeidrnos2tNetwork troubleshooting is finding where the conversation broke 🧭🌐 Don’t just say “the network is down.” Follow the message: DNS → IP → Route → Port → Firewall → NAT → TLS → Service The final Networking for Humans post brings the whole series together. #Networking #Troubleshooting #ELI5 #DevOp https://webdad.eu/2026/08/06/%f0%9f%a7%ad-troubleshooting-networks-is-finding-where-the-conversation-broke/06 Aug 2026 06:00 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3msfeidrnos2thttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mruwahsqia25My new book, The AI Agent Test Manual, is now available! AI agents are more than prompts and models. Production quality also depends on tools, retrieval, memory, permissions, external systems, evaluation pipelines, observability, and incident response. #AIAgents #SoftwareTesting #LLMEvaluation https://webdad.eu/2026/07/30/the-ai-agent-test-manual-is-now-available/30 Jul 2026 17:03 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mruwahsqia25https://bsky.app/profile/dominiksigmund.bsky.social/post/3mruscprxuw2x„Lebendige Worte 2“ ist da! 🎶 Zentrale Bibelverse treffen auf Geschichten aus dem heutigen Leben – musikalisch zwischen leisen Balladen, orchestraler Weite, Gospel und epischen Momenten. #LebendigeWorte2 #MessengerOfLight #ChristlicheMusik #Bibelverse #Glaube #Hoffnung #NeueMusik https://webdad.eu/2026/07/30/lebendige-worte-2-ist-da-bibelverse-fur-das-leben-heute/30 Jul 2026 15:53 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mruscprxuw2xhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mrtrfrclfp2w“The network is slow” is not a diagnosis 🐢🌐 Latency means waiting for a reply. Bandwidth means capacity. Packet loss means missing words. Jitter means weird timing. The new Networking for Humans post explains the difference. #Networking #Latency #ELI5 #DevOps #ITTraining https://webdad.eu/2026/07/30/%f0%9f%90%a2-latency-is-waiting-for-someone-to-reply/30 Jul 2026 06:04 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mrtrfrclfp2whttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mrc5yoit3o24TLS is sending letters in locked envelopes 🔐✉️ HTTP is a postcard. HTTPS protects the message with encryption and certificate checks. The new Networking for Humans post explains TLS without crypto headaches. #Networking #TLS #HTTPS #ELI5 #WebSecurity https://webdad.eu/2026/07/23/%f0%9f%94%90-tls-is-sending-letters-in-locked-envelopes/23 Jul 2026 06:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mrc5yoit3o24https://bsky.app/profile/dominiksigmund.bsky.social/post/3mqqkpn63zx26DHCP is the network receptionist 🏷️💻 New device joins? DHCP hands out the IP address, gateway, DNS settings, and lease time. The new Networking for Humans post explains automatic network configuration without acronym pain. #Networking #DHCP #ELI5 #ITTraining #DevOps https://webdad.eu/2026/07/16/%f0%9f%8f%b7%ef%b8%8f-dhcp-is-the-receptionist-who-hands-out-name-tags/16 Jul 2026 06:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mqqkpn63zx26https://bsky.app/profile/dominiksigmund.bsky.social/post/3mqpfupfiij2xMachina Dominus Tears Open Reality with New Album: Multiverse of Metal The Machine Lords have conquered Earth. Now they’re coming for your favorite universe. After their critically loud campaign of Digital Domination, where Machina Dominus seized control of Earth, the cloud, Skynet, and even… https://webdad.eu/2026/07/15/machina-dominus-tears-open-reality-with-new-album-multiverse-of-metal/15 Jul 2026 19:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mqpfupfiij2xhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mq6xixtjth23NAT is a hotel reception desk for the internet 🏨🌐 Your devices have private room numbers. The outside world sees one public address. The front desk keeps track of who asked for what. New Networking for Humans post is ready. #Networking #NAT #ELI5 #DevOps #ITTraining https://webdad.eu/2026/07/09/%f0%9f%8f%a8-nat-is-a-hotel-reception-desk-for-the-internet/09 Jul 2026 06:02 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mq6xixtjth23https://bsky.app/profile/dominiksigmund.bsky.social/post/3mpnkpmbc6w2tThe Nerdy Sixty | (51/60) Missing September Days | Challenge Understand the calendar switch of 1752: 11 days were omitted when the British Empire adopted the Gregorian calendar. https://webdad.eu/2026/04/20/challenge-cal-1752-missing-days/02 Jul 2026 07:58 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mpnkpmbc6w2thttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mpnkpcnpj62tThe Nerdy Sixty | (31/60) YouTube’s Robot Uprising | Solution Solution: Find the Easter egg comments in YouTube’s robots.txt referencing the year 2000 and a robot uprising. https://webdad.eu/2025/12/05/challenge-youtube-robots-txt_solution/02 Jul 2026 07:57 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mpnkpcnpj62thttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mpnkp777qn2uThe Nerdy Sixty | (46/60) Audible Ping | Solution Solution: Use the ping option -a (audible) which causes the terminal bell to ring on each ping response. https://webdad.eu/2026/03/20/challenge-audible-ping_solution/02 Jul 2026 07:57 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mpnkp777qn2uhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mpnkoujm2y2qThe Nerdy Sixty | (36/60) First YouTube Video | Challenge Identify “Me at the zoo” as the first YouTube video (uploaded by co-founder Jawed Karim) and its content. https://webdad.eu/2026/01/05/challenge-first-youtube-video/02 Jul 2026 07:57 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mpnkoujm2y2qhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mpne6zy7ft2iSubnets are neighborhoods for computers 🏘️💻 Same subnet? Local neighbor. Different subnet? Take the router road. The new Networking for Humans post explains subnet boundaries without binary panic. #Networking #Subnets #ELI5 #DevOps #ITTraining https://webdad.eu/2026/07/02/%f0%9f%8f%98%ef%b8%8f-subnets-are-neighborhoods-with-boundaries/02 Jul 2026 06:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mpne6zy7ft2ihttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mpe6y4o22d2uYou did it. 60 challenges. 6 arcs. 1 epic nerd journey. From ASCII cows to HTTP teapots, The Nerdy Sixty is complete. Come celebrate the finale #TheNerdySixty #DevFun #TerminalLegends #ChallengeComplete https://webdad.eu/2026/06/28/the-nerdy-sixty-complete-compiled-committed/28 Jun 2026 14:34 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mpe6y4o22d2uhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mp5gqw3pkt2eThe Nerdy Sixty | (60/60) Hello, World Origins | Solution Solution: Learn that the "Hello, World!" program first appeared in Brian Kernighan’s 1974 programming examples and was popularized by the 1978 K&R C book. https://webdad.eu/2026/06/26/challenge-hello-world-origins_solution/25 Jun 2026 22:04 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mp5gqw3pkt2ehttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mp3r7lxytj2hRouters are traffic cops for packets 🚦📦 They do not magically deliver everything themselves. They point each packet toward the next hop. The new Networking for Humans post explains routers, routes, and why packets sometimes get lost in traffic. #Networking #Routers #ELI5 #DevOps #ITTraining https://webdad.eu/2026/06/25/%f0%9f%9a%a6-routers-are-traffic-cops-for-packets/25 Jun 2026 06:06 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mp3r7lxytj2hhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3motetx4uz625The Nerdy Sixty | (60/60) Hello, World Origins | Challenge Learn that the "Hello, World!" program first appeared in Brian Kernighan’s 1974 programming examples and was popularized by the 1978 K&R C book. https://webdad.eu/2026/06/22/challenge-hello-world-origins/21 Jun 2026 22:03 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3motetx4uz625https://bsky.app/profile/dominiksigmund.bsky.social/post/3molthuyl5k27The Nerdy Sixty | (59/60) Year 2038 Problem | Solution Solution: Understand that on January 19, 2038, 32-bit Unix time will overflow, potentially causing software that uses 32-bit time_t to fail (similar to Y2K, but for Unix timestamps). https://webdad.eu/2026/06/19/challenge-year-2038-problem_solution/18 Jun 2026 22:04 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3molthuyl5k27https://bsky.app/profile/dominiksigmund.bsky.social/post/3mok5v7ockr26Ports are apartment numbers for computers 🚪🏢 The IP address gets your data to the building. The port tells it which door to knock on. The new Networking for Humans post explains network ports with apartments, doors, and zero packet panic. #Networking #Ports #ELI5 #DevOps #ITTraining https://webdad.eu/2026/06/18/%f0%9f%9a%aa-ports-are-apartment-numbers-in-the-same-building/18 Jun 2026 06:05 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mok5v7ockr26https://bsky.app/profile/dominiksigmund.bsky.social/post/3mobrfzdivq2tThe Nerdy Sixty | (59/60) Year 2038 Problem | Challenge Understand that on January 19, 2038, 32-bit Unix time will overflow, potentially causing software that uses 32-bit time_t to fail (similar to Y2K, but for Unix timestamps). https://webdad.eu/2026/06/15/challenge-year-2038-problem/14 Jun 2026 22:00 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mobrfzdivq2thttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mo2aevhyfh25The Nerdy Sixty | (58/60) Emacs Therapist | Solution Solution: Discover Emacs’s "doctor" mode, an ELIZA-like chatbot from the 1960s embedded in the editor. https://webdad.eu/2026/06/12/challenge-emacs-doctor_solution/11 Jun 2026 22:07 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mo2aevhyfh25https://bsky.app/profile/dominiksigmund.bsky.social/post/3mnyn3d6sro2xIP addresses are home addresses for computers 🏠💻 Without an address, your data is just a package saying: “To the person I mean.” The new Networking for Humans post explains IP addresses with delivery, houses, and zero subnet panic. #Networking #IPAddress #ELI5 #ITTraining #DevOps https://webdad.eu/2026/06/11/%f0%9f%8f%a0-ip-addresses-are-home-addresses-for-computers/11 Jun 2026 06:49 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mnyn3d6sro2xhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mnq6baxo522sThe Nerdy Sixty | (58/60) Emacs Therapist | Challenge Discover Emacs’s "doctor" mode, an ELIZA-like chatbot from the 1960s embedded in the editor. https://webdad.eu/2026/06/08/challenge-emacs-doctor/07 Jun 2026 22:02 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mnq6baxo522shttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mnimrrpuwe2jThe Nerdy Sixty | (57/60) 3D ASCII Demo | Solution Solution: Install the `bb` package to watch a retro 3D ASCII art demo animation in your terminal. https://webdad.eu/2026/06/05/challenge-bb-3d-demo_solution/04 Jun 2026 22:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mnimrrpuwe2jhttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mngx5v7yfx2iFirewalls are bouncers with a guest list 🚪🕶️ They check who is coming, where they want to go, which door they use, and whether the rules allow it. The new Networking for Humans post explains firewalls without the headache. #Networking #Firewall #CyberSecurity #ELI5 #DevOps https://webdad.eu/2026/06/04/%f0%9f%94%a5-firewalls-are-bouncers-with-a-guest-list/04 Jun 2026 06:01 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mngx5v7yfx2ihttps://bsky.app/profile/dominiksigmund.bsky.social/post/3mn6kxcykyy2iThe Nerdy Sixty | (57/60) 3D ASCII Demo | Challenge Install the `bb` package to watch a retro 3D ASCII art demo animation in your terminal. https://webdad.eu/2026/06/01/challenge-bb-3d-demo/31 May 2026 22:02 +0000at://did:plc:skloefe7veuiitsyjxbj3eui/app.bsky.feed.post/3mn6kxcykyy2i