What we watch for
Practical guides on monitoring, reliability, and performance — plus product news and lessons from keeping our own systems online.
104 articles
Heartbeat & Cron Job Monitoring: the Dead Man's Switch Your Backups Deserve
Most monitoring checks that something is up. Heartbeat monitoring does the opposite — it alerts when something that should run goes silent. The concept, who needs it, and how to set it up so a dead backup job can't hide for three weeks.
MCP Server Monitoring: Why "HTTP 200" Means Nothing to an AI Agent
MCP servers fail in ways no uptime check can see: the port answers 200 while the handshake breaks, tools vanish, or a tool description is silently rewritten under your agents. Here's how protocol-level MCP monitoring works — and why we built it.
Advanced SSH: jump hosts, tunnels, and power-user tricks
Once you know basic SSH, a whole toolbox opens up: jump hosts to reach private servers, port forwarding, SOCKS proxies, agent forwarding, and a config file that makes it all effortless. The power-user guide.
FTP vs FTPS vs SFTP: file transfer protocols explained
FTP, FTPS, and SFTP all move files — but only two are safe, and they work in completely different ways. Here's how each protocol works, active vs passive mode, the best clients per OS, and which to use.
SLA vs SLO vs SLI: the reliability promise, decoded
Three little acronyms quietly run every serious reliability conversation — and almost everyone mixes them up. Here's what SLA, SLO and SLI actually mean, how they fit together, and how to set ones that won't page you at 3am for nothing.
SSH explained: secure remote access, keys, and sessions
SSH is how you securely log into and control machines anywhere in the world. Here's what it is, how password vs public-key auth really works, how to run remote commands, and the best clients for every OS.
Alert Fatigue: why your team stopped reading alerts (and how to fix it)
When everything alerts, nothing does. Alert fatigue is how real outages slip past tired teams — and it's fixable. Here's why it happens, what it costs, and how to get back to a pager you can trust.
Status Page Best Practices: turning your worst day into trust
A status page is the one place customers look when things go wrong — and most are an afterthought. Here's how to run one that deflects tickets, calms users, and quietly earns trust during an outage.
Uptime Monitoring 101: how to never be the last to know
The worst way to find out your website is down is from an angry customer. This is the beginner-friendly guide to uptime monitoring — what it is, why it matters, and how to set it up so you always hear it first.
HTTP Status Codes Explained: what 404, 500 and 503 really mean
Every status code is your server trying to tell you something. Here's a plain-English guide to the ones you'll actually meet — what they mean, whose fault they are, and what to do about each.
Core Web Vitals Explained: LCP, CLS, INP (and how to keep them green)
Google grades your pages on three numbers — and they affect both how your site feels and how it ranks. Here's what LCP, CLS and INP actually measure, what 'good' looks like, and how to fix them.
How to Never Get Caught by an Expired SSL Certificate
An expired TLS certificate takes your whole site offline with a scary red warning — and it's 100% preventable. Here's why certificates expire, what it costs, and how to make sure it never catches you.
How DNS Works (and What 'Propagation' Really Means)
DNS is the internet's phonebook — and one of the most common causes of outages nobody understands. Here's how a domain name becomes an IP address, in plain English, plus what 'propagation' actually is.
The Blameless Postmortem: turning incidents into improvements (with a template)
After an outage you can hunt for someone to blame, or hunt for what to fix. Only one makes you more reliable. Here's how to run a blameless postmortem — plus a copy-paste template.
Synthetic vs Real User Monitoring (RUM): what's the difference?
Synthetic monitoring and RUM answer two different questions about your site. Here's what each one does, where each shines, and why the best setups use both.
API Monitoring Guide: how to watch the endpoints your business runs on
Your website can be perfectly up while your API quietly fails — and APIs power the integrations, apps and partners you can't see. Here's how to monitor them properly.
What is 99.9% Uptime? The downtime hiding behind the nines
“99.9% uptime” sounds almost perfect — until you do the maths. Here's exactly how much downtime each level of nines allows, how it's calculated, and how to pick a target you can actually hit.
On-Call Best Practices: a rotation that doesn't burn people out
Done badly, on-call wrecks sleep, morale and retention. Done well, it's a fair, calm safety net the whole team trusts. Here's how to build the second kind.
Website Downtime: the most common causes (and how to prevent each)
Most outages aren't mysterious — they come from the same short list of causes, again and again. Here's that list, what each one looks like, and how to stop it taking your site down.
Observability vs Monitoring: what's the difference (and do you need both)?
Monitoring tells you something broke. Observability helps you figure out why. Here's how the two differ, where each fits, and why modern teams lean on both.
Incident Metrics Explained: MTTR, MTTD, MTBF and friends
MTTR, MTTD, MTBF, MTTA — the alphabet soup of incident metrics, explained in plain English. What each measures, how to calculate it, and how to actually improve the numbers.
502 Bad Gateway: what it means and how to fix it
A 502 Bad Gateway means the server in front of your app couldn't get a valid response from the app itself. Here's what's really happening, the usual causes, and how to fix — and prevent — it.
DNS Record Types Explained: A, AAAA, CNAME, MX, TXT and more
Setting up a domain means meeting a zoo of record types — A, AAAA, CNAME, MX, TXT, NS. Here's what each one does, when to use it, and the gotchas that trip people up.
How HTTPS Works: the TLS handshake, explained simply
That little padlock does a lot of work. Here's what actually happens when you connect over HTTPS — the TLS handshake, certificates and encryption — without the cryptography headache.
Ping, Traceroute & MTR: network troubleshooting basics
When something's slow or unreachable, three classic tools tell you whether it's you, the network, or them. Here's how ping, traceroute and MTR work — and when to reach for each.
Incident Response: a step-by-step playbook
The alert just fired. Now what? A clear, repeatable incident-response process — from detection to all-clear — so the answer is never 'everyone panic'.
Email Authentication Explained: SPF, DKIM & DMARC
If your emails land in spam — or scammers send mail pretending to be you — these three records are why. Here's what SPF, DKIM and DMARC do, how they work together, and how to set them up right.
Latency & Percentiles: why p99 matters more than the average
Your average response time looks great — so why are users complaining? Because averages lie. Here's why percentiles like p95 and p99 tell the real story of how your service feels.
Webhooks 101: what they are and how to use them
A webhook is how one app says 'hey, this just happened' to another — instantly, without anyone asking. Here's what webhooks are, how they differ from polling, and how to use them well.
503 Service Unavailable: what it means and how to fix it
A 503 means your server is alive but can't handle the request right now — usually overload or maintenance. Here's what's happening, how to fix it, and how to keep it from surprising your users.
504 Gateway Timeout: what it means and how to fix it
A 504 means a proxy waited for your app to respond — and gave up. It's the signature of something slow, not something dead. Here's how to find the slowness and fix it.
What is a CDN? (And do you actually need one?)
A CDN makes your site faster by serving it from locations close to your users. Here's how that works, what you actually gain, and whether your site needs one.
TCP vs UDP: the difference, explained simply
Two protocols carry almost everything on the internet. TCP is the careful courier; UDP is the fast one that doesn't look back. Here's how they differ and when each is the right choice.
Rate Limiting & HTTP 429 Explained
Rate limiting is how services protect themselves from too many requests — and HTTP 429 is how they say 'slow down'. Here's how it works, and how to handle it gracefully on both sides.
IPv4 vs IPv6: what's the difference (and why IPv6 exists)?
Every device online needs an address — and we ran out of the old kind. Here's the difference between IPv4 and IPv6, why the switch is happening, and whether you need to care.
Email Blacklists (RBLs): why you're blocked and how to get off
If your email suddenly stops arriving, a blacklist may be the culprit. Here's what RBLs are, how you end up on one, and the step-by-step to get off — and stay off.
Disaster Recovery: RTO vs RPO explained
When the worst happens, two numbers decide how bad it really is: how much data you lose, and how long you're down. Here's what RTO and RPO mean, and how to set targets you can actually meet.
What is SRE? Site Reliability Engineering, explained
SRE is what you get when you treat reliability as an engineering problem instead of a firefighting one. Here's what Site Reliability Engineering actually means, its core ideas, and how it differs from DevOps.
What is TTFB (Time to First Byte) and how to improve it
TTFB is the first number that tells you whether your backend is fast or slow. Here's what Time to First Byte measures, what's 'good', what makes it bad, and how to bring it down.
404 Not Found: what it means and how to handle it
404 is the internet's most famous error — and unlike most, it's often nobody's emergency. Here's what it means, when it's fine, when it isn't, and how to handle it well.
403 Forbidden: causes and how to fix it
A 403 means the server understood you perfectly — and is refusing anyway. Here's what causes 'Forbidden', how it differs from 401, and how to track down the fix.
401 vs 403: Unauthorized vs Forbidden
401 and 403 are the two 'you can't have this' codes — and they're constantly confused. Here's the simple rule for telling them apart, with examples.
500 Internal Server Error: what it means and how to fix it
500 is the server's way of saying 'something went wrong and I don't know how to explain it.' Here's what causes it, how to find the real error, and how to stop it recurring.
301 vs 302 Redirects: which one should you use?
Both send visitors from one URL to another — but to search engines they mean very different things. Use the wrong one and you can quietly tank your SEO. Here's the difference.
CORS Errors Explained (and how to fix them)
Every web developer meets the dreaded 'blocked by CORS policy' error. It's not a bug — it's a security feature. Here's what CORS is, why the browser blocks your request, and how to fix it properly.
ERR_TOO_MANY_REDIRECTS: causes and how to fix it
When a page keeps redirecting to itself, the browser gives up with 'too many redirects'. Here's why redirect loops happen and the usual culprits behind them.
SSL/TLS Handshake Failed: causes and how to fix it
When the secure connection can't be agreed, you get a handshake failure — and the page never loads. Here's what goes wrong during the TLS handshake, and how to fix each cause.
Mixed Content Warnings: what they are and how to fix them
Your site is on HTTPS, but the padlock has a warning — or images won't load. That's mixed content: a secure page pulling in insecure resources. Here's how to find and fix it.
ERR_CONNECTION_REFUSED: what it means and how to fix it
Connection refused means you reached the server's door — and it slammed shut. Nothing is listening (or something is blocking). Here's how to track down which.
How to Monitor a Website (a step-by-step guide)
Monitoring your website sounds technical, but the essentials take minutes. Here's a plain, step-by-step guide to going from 'I hope it's up' to 'I'll know the second it isn't'.
Server Monitoring Basics: CPU, memory, disk and network
Before an app falls over, the server usually shows it coming. Here are the four resources to always watch — and what 'healthy' versus 'about to break' looks like for each.
Database Monitoring: what to watch (and why)
When the database struggles, everything that depends on it struggles too — usually as timeouts and slow pages. Here's what to monitor so the DB never becomes your silent bottleneck.
What is a Network Port? (and how to monitor one)
An IP address gets you to the right machine; a port gets you to the right service on it. Here's what ports are, the common ones, and why monitoring them catches outages a website check misses.
Keyword Monitoring: catching the '200 OK but broken' page
A page can return a perfect 200 OK and still be completely broken. Keyword monitoring checks the actual content — so a blank page, an error, or a defacement doesn't slip past your checks.
Monitoring Microservices: seeing health across many moving parts
Microservices trade one big app for dozens of small ones — and turn one dashboard into a puzzle. Here's how to monitor a distributed system without drowning in noise.
Monitoring Kubernetes: from pods to nodes to probes
Kubernetes is brilliant at hiding failures — it restarts and reschedules so smoothly you may not notice trouble until it's everywhere. Here's what to watch so the magic doesn't mask a problem.
Monitoring Serverless (Lambda and friends)
Serverless means no servers to watch — and a few new things that can go wrong. Here's what to monitor when your code runs as functions: cold starts, duration, errors and throttles.
How Often Should You Monitor? (choosing a check interval)
Check too rarely and you find out about outages late; check constantly and you pay for it. Here's how to choose a monitoring interval that matches what each service is actually worth.
Why Monitor From Multiple Locations?
Checking your site from one place gives you one opinion — and it's often wrong. Here's why monitoring from multiple global locations kills false alarms and reveals problems a single check can't see.
How to Speed Up Your Website (the high-impact wins first)
Website speed affects conversions, bounce rate and even SEO. The good news: most of the gains come from a short list of fixes. Here they are, roughly in order of impact.
LCP Explained: Largest Contentful Paint (and how to improve it)
LCP is the Core Web Vital that answers 'when does the page feel loaded?' Here's exactly what it measures, what counts as good, and the handful of fixes that move it most.
CLS Explained: Cumulative Layout Shift (and how to fix it)
CLS measures the most annoying thing on the web: the page jumping around as it loads. Here's what it is, what counts as good, and how to stop your layout from dancing.
INP Explained: Interaction to Next Paint (and how to improve it)
INP is the newest Core Web Vital — it measures how quickly your page responds when people actually interact with it. Here's what it is, what's good, and how to make your site feel snappy.
Lighthouse Explained: how to read the score
Lighthouse gives your page a 0–100 score across performance, accessibility, SEO and more. Here's what it actually measures, how to read it, and the trap of chasing a perfect 100.
Image Optimization for the Web (the biggest easy win)
Images are usually the heaviest thing on a page — and the easiest to fix. Here's how to make them load fast without looking worse: compress, resize, modern formats, and lazy loading.
Caching Explained: browser, CDN and server caches
Caching is the closest thing the web has to free speed: store a result once, reuse it many times. Here are the three layers of caching, how each works, and the one hard part — invalidation.
HTTP/2 vs HTTP/3: what actually changed
HTTP keeps getting faster. HTTP/2 fixed how requests share a connection; HTTP/3 changed the connection itself. Here's what's different, in plain terms, and whether you should care.
Gzip vs Brotli: web compression compared
Text compression shrinks your HTML, CSS and JS before they travel — for free speed. Here's how gzip and Brotli compare, and which to use where.
Web Font Performance: fast text without the flash
Custom fonts make a site look great — and can quietly slow it down or make text vanish during load. Here's how to keep your typography both beautiful and fast.
What is Latency? (and how to reduce it)
Latency is the delay between asking for something and getting it — and it shapes how fast everything online feels. Here's what it is, what causes it, and the practical ways to cut it.
Bandwidth vs Latency: what's the difference?
“I have fast internet, so why is this slow?” Because speed has two dimensions — bandwidth and latency — and they're not the same thing. Here's the difference, with a simple analogy.
What is Packet Loss? (causes, effects and fixes)
When data packets vanish in transit, calls stutter, games rubber-band and pages crawl — even on a 'fast' connection. Here's what packet loss is, what causes it, and how to track it down.
Anycast Explained: one IP, served from everywhere
Anycast is the clever routing trick behind fast CDNs and resilient DNS: one IP address answered by the nearest of many servers. Here's how it works and why it matters.
What is BGP? (and why it can break the whole internet)
BGP is the protocol that decides how traffic travels between the world's networks — the internet's routing map. When it goes wrong, large chunks of the internet go dark. Here's how it works.
What is a Reverse Proxy?
A reverse proxy is the front door to your servers — handling traffic before it ever reaches your app. Here's what it does, why nearly every serious site uses one, and how it differs from a forward proxy.
Load Balancing Explained
A load balancer spreads traffic across many servers so no single one gets overwhelmed — and quietly routes around the ones that fail. Here's how it works and why it's the backbone of scalable, reliable sites.
What is a Firewall?
A firewall is the gatekeeper that decides which network traffic gets through and which gets blocked. Here's what firewalls do, the main types, and the gotcha they create for monitoring.
What is an IP Address?
An IP address is how one machine on the internet finds another — the postal address of the digital world. Here's what it is, the difference between public and private, and the two versions in use.
What is NAT? (Network Address Translation, explained)
NAT is the quiet trick that lets all your home and office devices share a single public IP address. Here's how it works, why it exists, and the headaches it sometimes causes.
TLS 1.2 vs 1.3: what changed (and why it matters)
TLS 1.3 made HTTPS both faster and more secure than 1.2 — by doing less, not more. Here's what changed in the handshake, why it matters, and what to make sure your servers support.
HSTS Explained: forcing browsers to always use HTTPS
You redirect HTTP to HTTPS — but that first insecure request is still a risk. HSTS closes that gap by telling browsers to never even try HTTP. Here's how it works and how to deploy it safely.
What is a DDoS Attack? (and how to defend against one)
A DDoS attack drowns your service in traffic from thousands of sources until it buckles. Here's how these attacks work, the main types, and the practical layers of defence.
What is a WAF (Web Application Firewall)?
A regular firewall guards the network; a WAF guards your application — inspecting web requests and blocking attacks like injection and bots. Here's how it works and what it does (and doesn't) cover.
Zero Trust Explained
The old security model trusted anyone inside the network. Zero Trust throws that out: trust nothing, verify everything, every time. Here's what it means in practice.
What is a CVE? Vulnerability basics
When a security flaw is found in software, it gets a CVE — a global ID so everyone can track and fix it. Here's what CVEs are, how severity is scored, and how to stay on top of them.
Secrets Management Explained
API keys, passwords and tokens are the keys to your kingdom — and they end up hard-coded, committed to git, and shared in chat far too often. Here's how to handle secrets properly.
What is mTLS (Mutual TLS)?
Normal HTTPS proves the server's identity to you. mTLS goes both ways — the client proves itself too. Here's what mutual TLS is, where it's used, and why it's a Zero Trust building block.
Domain Spoofing and How to Prevent It
Scammers can send email that looks exactly like it's from your domain — phishing your customers and torching your reputation. Here's how domain spoofing works and how to lock it down.
DNSSEC Explained: signing DNS so it can't be faked
DNS was built without security — answers can be forged, sending users to fake servers. DNSSEC adds cryptographic signatures so resolvers can verify DNS answers are genuine. Here's how.
Why Your Emails Go to Spam (and how to fix it)
Your perfectly legitimate emails keep landing in junk — and you have no idea why. Here's how spam filters actually decide, and the practical checklist to get back in the inbox.
How to Set Up DMARC (step by step)
DMARC is what actually stops scammers spoofing your domain — but rushing it can block your own email. Here's the safe, staged way to roll it out from monitoring to full enforcement.
Email Bounces: Hard vs Soft (and what to do about each)
When an email can't be delivered, it 'bounces' — but not all bounces are equal. Here's the difference between hard and soft bounces, and why handling them right protects your deliverability.
BIMI Explained: your logo in the inbox
BIMI puts your brand's verified logo next to your emails in supporting inboxes — a trust signal and an anti-spoofing reward. Here's what it is, what it requires, and whether it's worth it.
Error Budgets Explained
An error budget turns the endless 'ship fast vs stay stable' fight into a single number both sides can see. Here's what it is, how to calculate it, and how it changes the way teams work.
Chaos Engineering Explained
Chaos engineering means deliberately breaking your own systems — in a controlled way — to find weaknesses before real failures do. Here's the idea, the method, and why it makes you more resilient.
Incident Severity Levels (SEV1–SEV4) Explained
Not every incident deserves the same response. Severity levels — SEV1 to SEV4 — give your team a shared language for 'how bad is this?' so the response always matches the reality.
How to Write a Good Runbook
A runbook turns 3am panic into a calm checklist. Here's what makes a runbook actually useful when an alert fires — and the mistakes that make them worthless.
Capacity Planning Basics
Run out of capacity at the wrong moment and your big day becomes an outage. Capacity planning is how you have the headroom before you need it. Here's the simple version.
High Availability Explained
High availability means designing so that one failure isn't an outage. Here's what HA actually means, the building blocks (redundancy, failover, no single point of failure), and how far to take it.
Feature Flags Explained
Feature flags let you turn functionality on and off at runtime — shipping code safely, releasing gradually, and rolling back instantly without a deploy. Here's how they work and why teams love them.
Canary vs Blue-Green Deployments
Two popular strategies for shipping without downtime — and without betting the whole site on a release working. Here's how canary and blue-green deployments differ, and when to use each.
CI/CD Explained
CI/CD is the automated pipeline that takes your code from commit to production — testing it, building it, and shipping it without manual drudgery. Here's what the letters mean and why it matters.
Infrastructure as Code Explained
Infrastructure as Code means defining your servers and cloud resources in version-controlled files instead of clicking through dashboards. Here's what it is and why it transforms reliability.
How to Choose a Monitoring Tool
There are dozens of monitoring tools, and the marketing all sounds the same. Here's a practical, vendor-neutral checklist of what actually matters — so you pick the one that fits your needs.