Overview
De Laender founded Coding Mammoth in 2007 to work on his own ideas and projects. Semonto started in 2006 as a side project built to monitor web application uptime during hosting problems, beginning with one developer and a designer, and later gained custom tests, alerts, SSL validation, and server monitoring. He leads Semonto from Coding Mammoth, supported by collaborators, beta testers, and ambassadors.
Jelle De Laender is the founder of Coding Mammoth, the Antwerp company behind Semonto. He founded Coding Mammoth in 2007 to work on his own ideas and projects. The product covers uptime and reachability checks, TLS certificate monitoring, broken link detection, Lighthouse performance testing, server health monitoring, cron job monitoring, and domain expiration alerts, with notifications through email, SMS, Slack, Teams, webhooks, and voice calls. Alongside the monitoring product, Coding Mammoth operates as a security partner for SaaS teams, offering fractional CISO leadership, ISO 27001 implementation and internal audits, security assessments, and incident response, covering frameworks including ISO 27001, GDPR, the AI Act, and NIS2. The company has also built ChaseMe, an iPhone fitness comparison app, MijnLijn, a public transport app for iOS, and QuickScale for macOS. Coding Mammoth is registered in the Belgian company register under enterprise number 0847.844.732, with a registration date of 6 August 2012, and is based at Krijgslaan 219 in Antwerp. De Laender also works with companies including Sketch, and his interests include security research, AWS, macro photography, and 3D printing.
Career history
Insights & ideas
The through-line
Across these posts, Jelle De Laender keeps returning to one idea: security and compliance are only useful when they are built in from the start, not bolted on later. He applies this lens to regulation (NIS2, the AI Act, ISO 27001), to client conversations about closing B2B deals, and even, half-jokingly, to a broken office coffee machine that gets a full "incident management procedure" [11][13]. Over the period covered, this preoccupation widens from process and audits into how AI is changing the threat model itself, and from professional writing into personal, physical challenges like the Dodentocht, where the same instinct for spotting things to improve shows up again, this time applied to his own side project ChaseMe [3][7].
On compliance by design
De Laender's clearest recurring argument is that compliance should be embedded rather than appended. Reacting to a podcast conversation about SaaS sales, he writes "compliance cannot be something you 'add later'" and says he believes "in compliance by design. Not as a big bureaucratic layer. Not as a separate team that slows everything" [13]. He extends this to regulation itself, arguing that "organisations with a mature ISO 27001 ISMS get a genuine head start" on the AI Act because "both are built on the same principles: governance, risk management, accountability, and continuous improvement" [5]. In Dutch-language commentary on a client's audit, he frames the goal the same way: not to "zo snel mogelijk een ISMS op te zetten" but to "effectief in controle te zijn," with agility coming from doing it early, before legacy and overhead build up [15]. He also tracks the regulatory landscape closely, noting Belgium's near two-year head start on NIS2 over the Netherlands and warning that "SaaS is not the legal test" for who the law applies to [4].
On AI's risks
He is an unambiguous power user of AI who is nonetheless wary of how others use it. "I'm scared of AI. Not of AI itself. Not of the technology. But of how people are using it," he writes, describing himself as running through a "Claude Max plan and an OpenAI Pro 20x plan every month" while still "challenging the PRs" an AI agent produces because "the logic, the architecture or the actual solution is not always the right fit" [9]. His concern is chiefly about context and blind trust: "Too many people are using AI blindly. Unknowingly. Without enough awareness. Without enough critical thinking" [9]. He connects this to a concrete new attack surface, citing "Agentjacking" research where a fake Sentry bug report can get an AI coding agent to "run commands on the developer's machine," concluding that with AI agents, tools like logs and error reports "are no longer just 'data sources.' They can become instruction sources" [10].
On small gestures and internet plumbing
De Laender is drawn to small, low-visibility mechanisms that quietly hold things together, whether social or technical. On a "Thank developer" button in the Homey App Store for his open-source Bose-speaker app, he writes "it's a nice reminder of how much UX, feedback and a little bit of gamification can influence how a product feels," reporting "133 active installations," "18 countries," and "193 Bose speakers brought back to life" [1], with an earlier count of "85 Bose SoundTouch speakers" restored [12]. He applies the same appreciation to internet-scale infrastructure, pointing out that "one of the most impactful security controls on the internet is maintained by a non-profit," noting that "around 59% of identifiable TLS certificates are issued by Let's Encrypt" and arguing "security is also about supporting the ecosystem we all depend on" [6]. He shows the same forward-looking, practical instinct in flagging Chrome's coming HTTP warnings, telling organisations the real risk is not the main website but "an old domain, forgotten subdomain or legacy service" [2].
Takeaways
- Build compliance into the product and sales process from day one rather than treating it as a late add-on if you want to close larger B2B deals [13].
- A mature ISO 27001 ISMS gives real head start on AI Act transparency obligations because both rest on the same governance and risk-management principles [5].
- Watch for NIS2 exposure signals like 50+ employees or over €10 million in turnover, since "SaaS" alone is not the legal test for applicability [4].
- Treat AI coding agents' inputs, including logs, error reports and observability data, as potential instruction sources that can be weaponised, as shown by the Agentjacking Sentry DSN attack [10].
- Audit forgotten subdomains and legacy internal services before Chrome 154 starts warning users about non-HTTPS sites [2].
- Small UX touches, like a "Thank developer" button, can meaningfully change how users feel about a product even without new features [1].
Media & appearances
- Jelle De LaenderYouTubeSemonto PulseCheck
In the news
- Hoe lang moeten de gegevens van jouw klanten vertrouwelijk blijven? Een jaar? Tien jaar? Langer? Die vraag is voor mij een goed vertrekpunt om over post-quantumcryptografie te praten. NIST publiceerde op 27 oktober een nieuw transitierapport. Een voldoende krachtige quantumcomputer zou bepaalde technieken achter onze beveiligde verbindingen en digitale handtekeningen kunnen breken. Gegevens die vandaag worden onderschept, zouden daardoor later alsnog leesbaar kunnen worden. Voor een SaaS-bedrijf zou ik de voorbereiding heel praktisch
- Apparently, I’m a security setting now 😅 Someone shared this screenshot last week in a chat with people I used to work with at a former customer. A Claude Code mode called “Jelle”: “Security focused, flags risks, follows least privilege, and validates safety before taking action.” I’m choosing to take that as a compliment 😂 One of the hardest parts of being a CISO is making security part of how a company thinks and works. Not just a policy people sign or something they remember when you join the meeting. Not everything is a
- Zes op de tien geteste Vlaamse gemeenten hebben geen plan bij cyberaanval" Een titel in De Tijd vandaag waar ik niet vrolijk van word. Het onderliggende rapport van Audit Vlaanderen bundelt onderzoeken uit 2023–2025. Bij 59% van de 70 onderzochte lokale besturen was geen ICT-bedrijfscontinuïteitsplan beschikbaar. Precies de voorbereiding waar ik SaaS-bedrijven mee ondersteun: wat moet er blijven werken als systemen uitvallen? Wie neemt beslissingen? Hoe communiceren we? En hebben we het herstel ook getest? Gemeenten vallen in België
- Soms is je SaaS-platform bewust offline halen de juiste securitybeslissing. Maar krijgen je gebruikers dan een duidelijke melding, of gewoon een foutpagina? (aan de Semonto notification queue te zien, veel foutmeldingen 🙈) En wat gebeurt er daarna? In mijn werk als fractional CISO kijk ik daarom verder dan de vraag: “Hebben jullie back-ups?” Wie mag beslissen om een dienst tijdelijk uit te schakelen? Wat kunnen klanten ondertussen nog doen? Wie communiceert met gebruikers en leveranciers? Moeten we een melding doen, ook al
- My LinkedIn feed is full of posts about the critical PHP vulnerabilities. From alerts to deeper analysis. Quite flooding but interesting. Meanwhile, we’re applying the patches ourselves. But I’m also watching something else: Semonto’s notification queue. And damn, it’s a busy day 😅 With so many teams patching and restarting their PHP servers, our monitoring servers are busy running checks and processing downtime notifications. You can practically watch the patching wave through the monitoring activity. Good luck to everyone
- Our SSL certificates renew automatically.” Good. But who notices when they don’t? 👮♂️ From 10 February 2027, Let’s Encrypt will issue and renew its default certificates with a 64-day lifetime instead of 90 days. That’s a positive security change. It also leaves less room for renewal processes that rely on fixed schedules. Imagine a script that attempts renewal only once every 60 days. With a 90-day certificate, that leaves roughly 30 days to recover from a failed attempt. With a 64-day certificate, it leaves about four. And
- Your toughest rival? Last year's you. ChaseMe 1.5 is out for iPhone and iPad 🎉 ChaseMe compares your year so far with the same day last year, straight from your Apple Health workouts. Ahead, on pace, or behind. Activity by activity. No leaderboards. No strangers. Just you against you 🕵️♀️ New in 1.5: - Richer year-to-date context: sessions, time and energy next to distance - Miles or kilometres, following your device settings 🙈 (internationalisation, always hard to spot) - Better workout cards to share: Light or Dark, an
- Besparen op cybersecuritykennis vind ik een verkeerde besparing 😬 (proof me wrong) Vanaf 1 januari 2027 stopt de KMO-portefeuille. Daarmee verdwijnt ook deze steun voor cybersecurityopleidingen en -advies. Aanvragen kunnen dit jaar nog zolang het beschikbare budget niet uitgeput is. (De aankondiging van VLAIO - Flanders Innovation & Entrepreneurship: https://lnkd.in/ezTF9Sw7) De overheid moet besparen. No discussion. En waar subsidies worden misbruikt, moet dat aangepakt worden. Maar voor cybersecurity vind ik het schrappen van deze
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