The most common mistakes in developing web solutions

The Most Common Mistakes in Web Solution Development

TL;DR:

• Every year, Slovenian businesses invest significant resources into developing web solutions that often fail to reach their full potential. Key mistakes include neglecting Core Web Vitals, security vulnerabilities, and delaying SEO and accessibility integration until late in development. With proper planning, early integration of these elements, and timely consultation, you can significantly improve user experience, efficiency, and security for your web project.

Every year, entrepreneurs in Slovenia invest time, money, and trust into web solution development projects that never achieve their full potential. The reason is rarely a lack of ideas or ambition. The most common mistakes in web solution development are technical and structural, often invisible to business owners until they feel the consequences in lost revenue. This guide shows you which problems appear repeatedly, why they are expensive, and how to avoid them in your next project using clear, proven steps.

Table of Contents

• 1. Ignoring Core Web Vitals Standards for User Experience

• 2. Security Vulnerabilities: How to Prevent the Most Common Pitfalls

• 3. Delayed Integration of SEO and Security into Development Architecture

• 4. Ignoring Accessibility and Ease of Use for All Users

• 5. Technical Issues That Affect Visual Stability and Site Performance

• Why Early SEO and Security Integration Is More Than a Best Practice

• How Moxy Web Helps You Build Error-Free Web Solutions

• Frequently Asked Questions

Key Takeaways

1. Ignoring Core Web Vitals Standards for User Experience

A successful web solution requires an excellent user experience, which today is also measured using Core Web Vitals standards. These are three metrics Google uses both to assess website quality and determine rankings in search results.

The three key metrics are:

• LCP (Largest Contentful Paint): measures how long it takes for the largest visible element on the page (image, heading) to load. The target is under 2.5 seconds.

• INP (Interaction to Next Paint): measures how responsive the page is to all user interactions, from clicking to typing. The target is under 200 milliseconds.

• CLS (Cumulative Layout Shift): measures visual stability — whether elements move around during loading. Google’s standard for CLS is 0.1 or lower for the 75th percentile of visitors, which directly impacts user experience quality.

Poor CLS is a mistake users immediately notice, even if they cannot name it. Imagine pressing a purchase button on your phone just as the page shifts and you accidentally click something else. The result is frustration and a lost customer.

The most common causes of poor CLS are images without predefined dimensions, ads that load late and push content downward, and fonts that switch during loading. The solution is simple and explained in more detail in the section about technical issues: assign every image "width" and height attributes directly in the code.

Expert tip: Use Google PageSpeed Insights to measure Core Web Vitals. Check results separately for mobile and desktop devices, as the values are often significantly different. Problems with website optimization are much easier to fix when identified early, not after launch.

2. Security Vulnerabilities: How to Prevent the Most Common Pitfalls

In addition to user experience, the security of your web solution is critical for protecting customer data and maintaining your company’s reputation. Common web development mistakes in this area are costly not only financially, but also reputationally.

Every year, OWASP publishes a list of the most important security risks for web applications. Broken Access Control remains the most common vulnerability (3.7%), followed by Security Misconfiguration and Software Supply Chain Failures. Let’s understand what this means in practice:

• Broken Access Control means the server does not properly verify who is allowed to view or modify certain data. The consequence: unauthorized users gain access to orders or personal customer data.

• Security Misconfiguration means default server or application settings were left unchanged. Typical examples include enabled test pages on a production server or publicly accessible admin panels.

Security-related mistakes in web application development often remain unnoticed until a breach occurs. At that point, fixing the damage costs far more than preventive measures would have.

How to protect yourself with clear steps:

1. Implement server-side access control checks for every individual request.

2. Deny access by default and explicitly grant permissions only where necessary.

3. Regularly update all libraries and plugins your solution depends on.

4. Implement request logging and monitoring systems.

5. Conduct an independent security audit at least once per year.

A comparison to the physical world helps: if you left your office doors unlocked every night because you forgot to change the default lock code, you would consider it a serious mistake. Website security works the same way. We recommend reading detailed website security advice and learning why web solution testing is an essential part of every project.

3. Delayed Integration of SEO and Security into Development Architecture

It is essential that SEO and security measures become part of the initial development phase of your web solution, not something “added later.” This is one of those mistakes entrepreneurs usually recognize only after fixing it becomes expensive.

Early integration of SEO and security into the project architecture reduces costs and shortens implementation time. When developers already understand the site structure and database, integrating metadata, canonical URLs, HTTPS, and security layers is straightforward. When you try to do this after launch, you often need to change the URL structure, requiring redirects and risking search ranking losses, while also reconfiguring security layers on top of existing code.

Examples of effective integration during development include:

• Defining URL structure and keyword strategy before writing the first line of code.

• Enabling HTTPS and security headers (Content Security Policy, HSTS) during server setup.

• Embedding structured data (schema markup) directly into page templates instead of adding it later.

• Agreeing on heading hierarchy (H1, H2, H3) during design, not afterward.

Clients who come to us for a redesign of an existing site often discover that two-thirds of their time and budget were spent fixing structural mistakes that proper planning could have prevented. See how web architecture affects your digital growth.

Expert tip: Before development begins, invite an SEO specialist to the kickoff meeting together with the developer. A single one-hour meeting can solve problems that would otherwise take weeks to fix. Reviewing alternative SEO approaches also helps you understand which tools and methodologies remain relevant today.

4. Ignoring Accessibility and Ease of Use for All Users

Your website should be accessible and easy to use for all visitors, not just those without special needs. Accessibility is not only an ethical commitment, but often a legal requirement and an SEO factor as well.

WCAG 2.2 standards require a contrast ratio of at least 4.5:1 for normal text and 3:1 for larger text or UI components. This ensures content remains readable for visually impaired users and those browsing in bright sunlight.

The most common accessibility mistakes in web application development include:

• Insufficient contrast between text and background, often seen in modern gray color palettes.

• Images without descriptive alternative text (alt text), making them inaccessible to screen readers.

• Buttons and links without clear labels indicating their purpose.

• Forms without visible field labels or forms accessible only with a mouse, not a keyboard.

The consequences of these mistakes are not limited to excluding part of your target audience. Search engines interpret alt text, heading structures, and form labels similarly to screen readers. An accessible site is generally also easier for search engines to understand.

Steps for achieving WCAG 2.2 compliance:

1. Check color contrast using a tool such as Colour Contrast Analyser.

2. Add alt text to every image describing its content within the page context.

3. Ensure the entire navigation and all content are fully accessible by keyboard without a mouse.

4. Test pages using screen readers such as NVDA or VoiceOver.

Good accessibility is an investment that broadens your audience. A more detailed overview of what website development actually includes will help you ask the right questions from the very beginning.

5. Technical Issues That Affect Visual Stability and Site Performance

Technical details during content loading significantly reduce visual glitches and improve page speed. One of the most commonly overlooked issues is incorrect lazy-loading implementation.

Lazy-loading is an approach where images and videos load only when the visitor scrolls near them. This is a good practice for content lower on the page. However, lazy-loading above the fold causes layout shifts during loading, directly damaging CLS scores and frustrating visitors.

Image dimension mistakes are surprisingly common even among experienced developers working under time pressure. When the browser does not know how much space an image will take, it cannot reserve the space and content jumps downward during loading.

Expert tip: Establish a rule in your codebase that no image or video may be added without explicit width and height attributes. This takes one minute during development and saves hours of troubleshooting later. In outdated website redesign projects, these details often make the biggest difference in results.

Why Early SEO and Security Integration Is More Than a Best Practice

After years of working on projects for small and medium-sized businesses, we at Moxy Web noticed a pattern repeating with remarkable consistency. Clients who approach us with an existing website asking for a “small SEO fix” usually need a much larger intervention that costs several times more than the originally planned development.

Retroactively adding SEO and security doubles costs and extends timelines. This is not an opinion — it is simple math. Changing URL structures after launch requires redirect planning, testing, waiting for re-indexing, and monitoring ranking fluctuations. Adding security layers to an existing architecture often reveals conflicts between components originally built without security in mind.

Here is the contradiction most businesses realize too late: “faster” development without SEO and security at the beginning actually becomes slower and more expensive overall. Clients who plan one month for development and one month for optimization often end up finishing in three or four months because optimization exposes structural flaws.

Our recommended practice is simple and proven. The SEO specialist and developer sit together at the very first project meeting before anything is built. Security requirements become part of the specification, not a post-launch task. The result is a solution that works from day one, not six months later. Strong web architecture for growth is not built after the house already stands.

How Moxy Web Helps You Build Error-Free Web Solutions

The mistakes described above are not inevitable. But they are common in projects where developers, designers, and business goals are not aligned from the start. At Moxy Web, we approach every project with an individual analysis that includes reviewing security requirements, SEO architecture, and technical specifications before the first design mockup is even created. Our team helps you identify risks before they become expenses.

If you have an existing solution that is not delivering expected results, or if you are planning a new project, we invite you to schedule a free consultation. Together we review your website security and identify opportunities for website optimization. Every project we take on is built on foundations designed for long-term growth.

Frequently Asked Questions

What are the most important Core Web Vitals and why do they matter?

Core Web Vitals are LCP, INP, and CLS — metrics that measure loading speed, responsiveness, and visual stability of a website, directly affecting both user experience and Google search rankings.

How do I prevent Broken Access Control vulnerabilities on my website?

Prevent them with consistent server-side access checks for every request, deny-by-default permission settings, and regular request logging and monitoring. Broken Access Control remains the most common security vulnerability and requires a strict, systematic approach.

Why is it important to include SEO and security from the start of development?

Because adding SEO and security later doubles costs and extends implementation time, since post-launch changes require extensive redirects, configuration fixes, and a full architectural review.

How do I make my website accessible for visually impaired users?

Follow WCAG 2.2 standards, which require a minimum contrast ratio of 4.5:1 for normal text and 3:1 for larger text and UI components, while also ensuring all images include descriptive alt text.

What is lazy-loading and how does it affect site stability?

Lazy-loading is a technique that loads images and videos only when they enter the visible viewport. Incorrect implementation — especially for above-the-fold elements without reserved space — causes layout shifts and poor CLS performance.

Recommended

• Moxy Web - Web Architecture: The Key to a Better Online Presence

• Moxy Web - Step by Step to Successful Web Application Development

• Moxy Web - How to Design Unique Web Solutions for Business Growth

• Moxy Web - Choosing the Right E-Commerce Platform