- Industrija
- Energy and conference organization
Obim rada
Redesign, custom theme, SR/EN, B2B and booking
Outcome
Mobile Lighthouse performance improved from 29 to 99, with migration completed without losing bookings
Client: the National Biomass Association “SERBIO”
Project: events-serbio.rs — the SEE ENERGY Regional Energy Conference
Volume: Complete redesign, custom WordPress theme, bilingual structure, B2B platform, booking system
Year: 2026.
Who is the client
the National Biomass Association “SERBIO” from Novi Sad organizes SEE ENERGY — Regional expert energy conference and exhibition dedicated to the energy transition.
The event brings together decision-makers, companies, investors and institutions from the energy, industry and finance sectors. The 2026 edition is held on November 4 and 5 at the Master Center at the Novi Sad Fair, with over 300 participants, 40+ lecturers and 100+ companies. Topics include battery storage (BESS), utility-scale projects, electromobility, biogas and biomethane, PPAs, digitalization of the energy sector and financing of energy projects.
Among the partners and institutional support of the previous edition are Siemens Energy, IBM, EBRD, Erste Bank, EPS, EY, Lafarge, Ministry of Mining and Energy, Serbian Chamber of Commerce and UNDP.
In other words — the site is not a presentation. The site is an operational tool through which to pass registrations, partner applications, B2B meetings and communication with a serious international audience.
Initial state
The existing site was WordPress, done internally — in the house, with partial knowledge of the code and structure of the platform.
And this should be said openly, without fence: The site looked decent. It was clear that considerable effort went into it and a clear idea of what should be shown. This is one of those situations that we often encounter — owners and teams who sit down and do something they do, because there are reasons why they did not immediately hand it over to the agency. Sometimes it is a bad experience from before, sometimes the price, sometimes simply because the team they contacted was not specialized in WordPress.
The problem wasn’t the taste. The problem was the relationship between the amount of content and the way that content was distributed.
The conference of this volume generates a huge amount of information — program, speakers, partners, institutional support, galleries, news, B2B company profiles, price list, registration fees, location, contact team. When all this is arranged vertically, without a compact layout, on a mobile phone you get a page through which the user scrolls unpleasantly long before reaching the information they need.
And the technical indicators were clear:
| Metrics | Old site |
|---|---|
| Lighthouse Performance — Mobile | 29 |
| Lighthouse Performance — desktop | 42 |
For a site that receives traffic from LinkedIn posts, email campaigns and media announcements — Mostly from the phone. — This is a direct loss of registration.
What was to be achieved
The client came up with four clear goals:
- Better legibility — Information to be found, not leaked.
- A more visual impression — The site should show the weight of the topic and the credibility of the organizers in front of the partners of the Siemens Energy and EBRD caliber.
- Conversions — conference registrations, registrations of partners and exhibitors, registration of speakers.
- All this without interrupting the operation of existing systems — bookings, user accounts and B2B data must survive the migration intact.
Access to design
We wouldn’t say we’ve simplified AI. — There’s still a lot of content, and that’s how it should be.
We distributed the content strategically, prioritizing the elements that lead directly to conversion.
A completely new start. Designed from scratch, with a clear hierarchy: ticket date and price immediately at the top, hero section with direct CTAs for booth and speakers, then numbered sections (01 Program, 02 About Conference, 03 Tickets, 04 Speakers…) which give the user a sense of orientation instead of an infinite flow.
The rest of the site aligned with the new home. Each subpage assumes the same system of typography, spacing, and components, so that the site acts as a single whole, rather than as a set of different templates.
Mobile review solved by horizontal sliders. This was a crucial decision. Sections with a large number of items — speakers, partners, institutional support, media partners, video interviews — on mobile are displayed as horizontal sliders instead of vertical lists. The content is still all there, it is still beautiful and readable, but the length of the page is drastically shortened. The user scrolls through the sections, not through the items within the sections.
New custom theme, made specifically for the client. No page builder, no universal template purchased on the marketplace. With it, the purchased bloat from the old site was cleared — A dozen plugins have been removed. whose functions have either ceased to be necessary, or have gone directly into the subject.
Technical performance
This is where the project stops. “”Redesign” is becoming more serious.
The site is not just a set of pages. Behind it stands several systems that must work together:
- Custom WordPress Theme with ACF
- Polylang SR/EN Structure
- Amelia booking system and user panel
- Custom B2B Platform
- Custom post types for speakers, partners, companies, galleries, team
- RankMath SEO
- Forms, user accounts and automation
- Cloudflare and more cache layers
The redesign meant that each of these systems had to reconnect properly on a new theme — No loss of data.
Real bilingualism, not just translated text
SR version without prefix, EN under /en/. But multilingualism on such a site is not a translation of the text — It’s a parallel structure.
It was necessary to correctly connect separate header and footer menus by language, SR/EN pages and all CPT records, internal links, language appropriate PDF programs, as well as companies, galleries, speakers, partners and team members.
Key detail: the content is not connected by matching the same slug, but through the actual Polylang translation relationship and the corresponding object ID. Connecting content by slug is a common shortcut that works until one day it stops — Usually when someone changes the title of a page.
Company content without duplication of common data
For company profiles on the B2B platform, special EN fields have been introduced for company description, title of each representative and CTA text. Logo, name of the representative, company website and Amelia mapping remain common for SR/EN pair — Because the name of the man and the logo of the company are not translated.
An interesting edge case appeared here. EN template was downloaded by the whole repeater from the SR post, which is why the EN title entered in the English translation was completely ignored. The solution connects representatives by name, along with fallback in order, and applies a clear priority: EN title from EN post → EN title from the related SR post → SR title only if EN is not filled.
After the correction, 19 publicly displayed titles automatically switched from Serbian to entered English values — without any change to the contents of the database.
B2B profiles public, booking protected
Instead of locking the entire B2B platform behind the login, a more precise division has been made:
- Company profile, description and representatives — publicIndexed and Visible
- Amelia booking form to schedule a meeting — Request an application
- messages and login links adapted to the language in which the user is located
- SR and EN versions of the same company use The same Amelia Employee/Service entities, so appointments and reservations are synchronised between languages
This is a balance between SEO visibility, user experience and access control. Google and AI search engines see who is participating in the conference. A meeting can only be scheduled by a registered participant.
Automate logins
A workflow has been created where the login type “Ticket” manually approves, after which the system automatically creates an Amelia customer record, creates a WordPress user account, assigns a corresponding roll, prevents duplicate accounts and displays an understandable error if the email already belongs to an existing user.
Password reset stream is adjusted so that the user does not end up on the generic after defining the password wp-login.php Go directly to the user panel.
Work on active production
The site was developed in a staging environment and then migrated to maintenance window of three hours, during which data and connected existing systems were transmitted. Three hours was the entire period during which the site was inaccessible to visitors — From that moment on, everything worked.
But part of the work had to be done directly on a live site. — because there were already active reservations and user orders that were not allowed to be touched.
Key Production Decision: no full database import was made over the live database. This would be a faster path, but it could overrun the active wp_amelia_* reservations and users. Instead, targeted migrations, idempotent importers, individual targets and relationship corrections, backup bases before each set of changes and one-time tools for audit and cache purges that delete themselves after use were used.
Each file change is accompanied by a hash-verified rollback.
Rollback is not a theory.
During one of the last fixes, it was discovered that production PHP does not have mbstring extension. A function that worked locally caused a critical error on the live server.
The order was:
- Error detected by final test
- immediately returned hash-verified backup template
- Confirmed that all 27 companies are showing up again
- read server error log
- Imprint
mbstringDependency - Reload, cache and test SR and EN routes
This is a detail worth highlighting. Backup and rollback are not an item in the offer that sounds nice — it is an active part of the process. The difference between “the website broke” and “the website was unavailable for two minutes” is exactly whether the rollback plan exists before it is needed.
Performances
Here is the biggest measurable benefit of the project.
| Lighthouse Performance | Mobile | Desktops |
|---|---|---|
| Old site | 29 | 42 |
| New site | 99 | 100 |
The new theme started with a mobile score of 96 and Speed Index of 3.8 s. This was already a huge jump compared to 29 — but we wanted to finish the optimization properly, so another round of optimization was done based exclusively on Lighthouse data:
- preload LCP hero images from
<head> - correct
imagesrcsetandimagesizesAttributes fetchpriority="high"and synchronous decoding of LCP images- Precise
sizesfor mobile logo - removing unused Gutenberg/global CSS from the ACF home page
- Additional WebP compression without changing dimensions or URLs
Concrete results per resource:
| Resource | Before | After | Savings |
|---|---|---|---|
| Mobile hero 768×576 | 40.8 KB | 19.6 KB | −52% |
| Full Hero | 378.9 KB | 85 KB | −78% |
| Mobile logo | 16.6 KB | 6.4 KB | −61% |
| HTML Home | 158,6 KB | 145.3 KB | −8% |
Anonymized Chrome test at resolution 390×844 confirmed that there is no horizontal overflow and that the browser does indeed select less responsive image variants — What is the thing that srcset It often seems to resolve itself.
For those who like technique
A common way to remove WordPress global CSS is wp_dequeue_style('global-styles'). However, WordPress 7 on classic themes can reenqueue it in the footer, and then “host” back to <head>.
As a result, it was necessary to remove the global styles placeholder, remove the late wp_footer enqueue and limit optimization only to the home page — which renders through custom ACF template and does not use Gutenberg blocks. Optimization does not apply to sites that use blocks, as it would do damage there.
Accessibility and AI Agents
Lighthouse and agent browsing tests reported a link to the parent SERBIO site as a link without a recognizable name — because it consisted only of a picture with an empty alt attribute.
The correction included a meaningful aria-label, security noopener noreferrer attributes and check the actual accessibility of the tree in the browser.
The final test confirmed that the element was recognized as a link, that it was not ignored and that it bore the name “SERBIO — National Biomass Association”.
This is more than just a formality around screen reader. AI agents who search and navigate websites today use the accessibility tree. The nameless element does not exist for them.
SEO Migration
The new pages in RankMath were blank, so a controlled padding was done:
- Inscribed 38 SEO Values
- no existing value is overrun
- verified canonical URLs, language routes and sitemap behavior
- structural CPTs that only serve to display within pages are deliberately excluded from the sitemap, so as not to dilute the index with empty URLs
The result
The client today has a website that:
- Loads for 99/100 Lighthouse instead of 29/42
- Displays the same amount of content with a noticeably shorter mobile scroll
- works in parallel in Serbian and English, with real links between languages
- Leads registrations, partner logins and B2B scheduling through one system
- has a clean SEO base and accessibility ready for AI search
- stands on a custom theme made for it, with a dozen plugins less
Equally important, all this was achieved with three hours of unavailability, no lost booking and no lost user account.
All recommendations for RXN Web Solutions! Great team, quick and easy communication. All changes and requests were dealt with practically immediately, with a lot of patience and good suggestions. The redesign of the site was done exactly as we wanted, and the whole process went easily and without complications. Really great experience and a team to work with again.
Jelena Buncic — President of the National Biomass Association “SERBIO” and organizer of SEE ENERGY event
Why we share this
Because this is a good example of what we mean when we say we do WordPress.
It’s not about making a beautiful site. The point is to know what’s going on underneath — how Polylang really links content, why it is global-styles returns to footer on WordPress 7, what happens to active Amelia bookings if you do a database import, and how the site reverts to a previous state when something breaks on production in half the work.
You don’t see that knowledge on a screenshot, you only see it when you need it.
If you have a site that has outgrown its original setting — whether you made it yourself, whether it was done by someone else — Contact usWe will take a look at the current situation and tell you honestly if you need RedesignEither that, or a couple of targeted interventions are enough.