Zlaja 2015

The sitemap lists twenty-five URLs, and they are not random. The home page, ten service pages, an overview page of the covered municipalities and seven municipality pages, the gallery, about, contact, an emergency call-out page and the legal texts.

The service pages are split according to how people actually search: an overview of plumbing services, then separately drain unclogging, WOMA high-pressure cleaning, water heater installation and servicing, septic tank emptying, replacement of pipes, faucets and traps, bathroom fixture fitting and electrical services. Each has the same skeleton — what the service is, how it is done, frequently asked questions, a call to action at the end — but not the same text. The WOMA page compares high pressure with cable cleaning and explains when each is better. The water heater page lists the types and the most common faults. The septic tank page covers when emptying must not be put off.

In the first version, the municipalities were handled the opposite way from the usual approach: instead of seven nearly identical pages with only the municipality name swapped — the fastest way to get Google to rate that whole section of the site as thin content — the /vodoinstalater-zemun and /vodoinstalater-palilula URLs, and others like them, led to a single page about the covered municipalities and pointed to it with a canonical tag. At the end of August 2026, each of the seven municipalities got its own page with its own text about the neighborhoods, the type of buildings and the faults that come up most often there, and with its own canonical URL, while the overview page stayed as a summary. All covered municipalities, together with neighborhoods such as Kotež, Borča, Krnjača and Mirijevo, are listed on the page about locations across Belgrade.

There is exactly one thing the visitor needs to do on the site, and it is not hidden. On November 12, 2026, the home page got a new look: the headline “We come in our own vehicle, with our own machine”, right below it what the business fixes, a single call button and the rating from its Google profile. All photos are from the business itself.

Below the headline come five scenes that stay pinned on screen while you scroll, on phones too: the vehicle fleet, the WOMA machine, the drain cable, the septic tank truck and completed jobs. Each one says what the machine does and which problem it solves, so before calling, the visitor sees that the business comes with its own equipment. On phones, a bar with the number stays at the bottom of the screen, and the page ends with a “Call any time” contact section, with 24-hour opening hours and the address in Kotež.

The contact form exists as a second option, for those who do not call right away but want an estimate. Messages go through the PHP function mail() to the mail server on the same machine, from an address on the business's domain. One detail once took far too much time: in the message text, the word “BEOGRAD” had a Cyrillic letter O instead of a Latin one, three times. It looks identical but is not the same letter, and a small thing like that can push a message toward the spam filter.

For a tradesman, the gallery matters more than in most industries. When someone is choosing whom to let into their apartment at two in the morning, a photo of a finished job is worth more than any description. That is why the work gallery is not decoration but an argument.

Filters split it into completed jobs, vehicles and equipment. Jobs show photos from the field: patching pipes, fitting a toilet, fixing a leak. Vehicles and equipment show what you cannot rent by the day — the Rotenberg machine, the septic tank truck, a thermal camera for leak detection and the business's vehicles. Every image exists in two WebP versions, a smaller one for the grid and a full-size one for viewing.

The gallery also produced a finding that is easy to overlook. The lightbox originally had an empty <img src=""> element that was filled in only on click. The browser treats an empty image source as a request for the current page, so the whole page was loaded a second time just to be thrown away. It was replaced with a transparent one-pixel placeholder, and the unnecessary request disappeared.

The site has a language switch in the header. The usual solutions are two sets of files, a translation database or an off-the-shelf plugin — all three mean every text change has to be made in two places, and in practice the second place gets forgotten.

Here it was done differently. Text is written in the HTML as a pair, the Serbian and then the English version separated by a single character, on an element that carries data-translate. Before the page is sent, PHP's output buffer goes through the document and keeps only the half of each pair that matches the cookie with the chosen language. The translation sits exactly where the text it translates is, so the two cannot drift apart.

The catch was in the cache. The site sits behind an nginx FastCGI cache, which means a finished page is stored and served without running PHP — and that is exactly the step that picks the language. Without a fix, the first visitor would set the language for everyone else for the next ten minutes. It was solved by bypassing the cache when the cookie asks for the English version, so only the Serbian version is cached. It is the kind of bug that does not exist in testing, because a test is always run by one person with one language, but on the live site it shows up immediately.

The site is written in PHP 8.5 behind nginx, without WordPress and without a single plugin that would need watching and updating. Pages live in their own directories, the shared parts — header, footer and the closing call-to-action bar — in a shared include, and the styles are split into a critical part inlined in the page and the rest, which loads afterwards.

In front of everything sits a FastCGI cache with its own zone and a ten-minute lifetime. The cache stores only GET and HEAD responses, so form submissions always reach PHP — because a cached response to a submitted form means another visitor sees someone else's confirmation.

Three things from the server configuration are worth singling out, because they come up everywhere and cost a lot:

• The redirect from the www address dropped the path. The rule returned the bare domain instead of the domain with the path, so every link to the www version of a subpage ended up on the home page. One missing argument on one line, and it means that every shared URL and every backlink to a subpage does not land where it should.
• The rule that blocks access to hidden files also blocked /.well-known/, and with it security.txt. The fix is an exception placed before the block, not instead of it.
• For some visitors, the site was in the wrong place. The zone had an IPv6 record, but the vhost listened only on IPv4. Visitors on networks that try IPv6 first — and in Serbia that includes the mobile operators — did not reach the right vhost. The fix is one line per block, but you will not find it by looking at the site in a browser, because on most connections everything looks fine.

On top of that, the home page has a locked attribute at the file system level as protection against unauthorized changes. In practice, every deploy has to remove the lock first and then put it back — which is deliberately inconvenient, because that is the point.

Measurements were taken before and after, in two passes, and the biggest gain did not come from where you would expect.

On mobile, the performance score went from 83 to 97 in the first pass and to 98 in the second. The time the main thread was blocked fell from 610 milliseconds to 170, then to 140. Mobile LCP was brought down from 2.3 seconds to 2.1. Accessibility is 99, SEO 100, and best practices went up from 96 to 100.

The decisive move was not image compression but when Google Tag Manager loads. Instead of starting right away, it was deferred until the visitor's first interaction — a scroll, tap or click — or until four seconds after load, whichever comes first. Analytics still measures everything it needs to, but it does not hog the processor while the page is being drawn. That one change brought more than two thirds of the total gain.

The nicest finding was with the fonts. The subset with the accented letters was not preloaded, and the font was set up not to be waited for if it was not ready. The result: on a first visit with an empty cache, the letters č, š, ž, ć and đ fell back to the system font — in the heading “Električar”, one letter came from a different font, visibly larger and darker. On every later visit everything looked right, so the bug survived for months. It was fixed by adding the preloaded subset to all twenty-two pages.

What was not solved is worth stating just as clearly. Layout shift during loading on desktop stayed at 0.194, above the recommended threshold. An attempt to reserve the height in advance made it worse, at 0.265, so it was rolled back. A real fix needs the hero section layout reworked, not one more property added. On mobile, where this site's traffic is, the value is below 0.01.

The hero section was reworked with the new home page design on November 12, 2026. A measurement the same day, Google PageSpeed: performance 100 on both phone and desktop, layout shift 0.001 on phone and 0.002 on desktop.

Every page has its own title, description and canonical URL, Open Graph and Twitter cards, and structured data that matches what is on it. The home page and the service pages carry the Plumber type with the address, phone number, opening hours from 00:00 to 23:59 all seven days and the service area. The municipalities page lists twenty administrative areas as areas served. The questions the client actually gets — how much unclogging costs, what the warranty is, what the WOMA system is — are marked up as FAQPage so that their content is machine-readable. Google decides for itself whether and how to show a rich result, and for most business sites the FAQ rich result is no longer shown.

There were also two passes through the W3C validator. The first showed four to six errors per page on all fifteen pages checked; after the second there were zero on all of them. The errors were not so much cosmetic as contagious — one extra closing tag sat in the shared include for the closing bar, so it repeated on every page of the site. Besides that: a block of styles placed directly in the footer instead of the CSS file, a font preload tag with an invalid value that the standard does not allow, and skipped heading levels where an H4 came right after an H2.

On the infrastructure side, the DMARC policy was raised from monitoring to quarantine for all messages, CAA records were added that define who may issue a certificate for the domain, and a security.txt file was published with a contact for reporting vulnerabilities. The sitemap was cleaned up after a pass through Search Console — redirecting URLs have no place in a sitemap, because Google picks them up from there, sees the redirect and reports them as not indexed.

Alongside the site, an app for running the business was built on a separate subdomain. It is not public and not part of the site — search engines do not index it, and sensitive directories are locked down at the server level.

It is a single-page app that installs on a phone like a real app and works even without a connection, which is not a luxury in this line of work — half the call-outs are in a basement or boiler room with no signal. The panel holds what a tradesman actually needs:

• Work orders with a status — pending, in progress, completed, unpaid, canceled — and a priority from low to urgent. Each order comes with photos from the field and a link to the client.
• Clients split into individuals and companies, with multiple contacts and a tax ID (PIB) for companies, and statistics per client: how many orders there were, how much was paid, how much is owed.
• Expenses by category — materials, fuel, wages, tools, vehicle, office — tied to a specific order, so you can see what each job really cost.
• Reports: monthly with income, expenses and the difference, yearly by month, and an overview of performance per technician.
• Roles: the administrator sees everything, a worker sees only their own open orders. Someone out in the field does not need to see other people's billing.

The “unpaid” status as an equal item next to “completed” is a small detail that shows who the app was written for. A job that is done and a job that is paid for are not the same thing, and for a tradesman that difference is the most expensive item of the year.

A site that is his own. No monthly platform subscription, no plugins that fall apart with the next update, no license that expires. The code and the database sit on the server and can be copied.

In practice it looks like this: someone types the service and their part of town into a search, opens a page about exactly that service, and has the number under their finger before scrolling at all. The call comes in on one number. The job is entered in the panel on the phone, with a photo and a price, and at the end of the month there is a report instead of a guess.

The site is in active maintenance. The last full pass covered nineteen pages on two screen sizes plus the panel: no console errors, no horizontal overflow, no broken images, all sitemap URLs reachable, and the form checked all the way to message delivery. Whatever changes is changed on the live site, with a backup before every edit.