GMI Software
Services

Start with the outcome you need to achieve.

Explore all services
Core areas
01AI & AutomationFrom workflow and business case to production02Mobile AppsiOS, Android, React Native03Headless & B2B commerceStores, sales platforms, ERP/PIM integrations
Complementary services
AI-gen developmentAgents, RAG and LLM integrationsE-commerce mobile analyticsFunnel measurement and data-led decisionsProduct Discovery & DesignScope, prototype and delivery planBackend, API & IntegrationsSystems connected to business operationsMaintenance & AuditsStability, performance and continued growthWorkshops & estimationRisks, decisions and fixed-price scope
Not sure where to start?Book a short consultation
Our projects
Case studies and references
App Ideas Library
Use case examples
Technologies

We choose the stack around the product, scale and risk.

Explore the full technology stack
MobileReact NativeExplore
CommerceMedusaJS + headlessExplore
Frontend & QA
Next.jsReactTypeScriptPlaywrightMaestro
Backend, DB & cloud
Node.jsNestJSPostgreSQLDockerAWS
AI, 3D & automation
3D configuratorsAI agents & automationRAG & knowledge basesAI-native products
Explore the full technology stack
Before you commit

Estimate costs and organise assumptions before a call.

App cost calculatorEstimate scope and budgetE-commerce AI adviserMap decisions, risks and optionsE-commerce TCO calculatorCompare SaaS and custom over 5 years
About us
Our history and values
Careers
Join our team
Contact
Get in touch
Get in touch
AI Opportunity Sprint
Services
Mobile AppsHeadless & B2B commerceAll services
Projects and results
Technologies
Next.jsNode.jsAWSFull technology stack
Tools
App cost calculatorEstimate scope and budgetE-commerce AI adviserMap decisions, risks and optionsE-commerce TCO calculatorCompare SaaS and custom over 5 years
Meet GMIGet in touch
Back to blog
Product design
Published: July 29, 2026
8 min read

What is a mockup, and why should you create one before coding?

A mockup shows product layout, hierarchy and visual direction before expensive implementation starts. This guide explains the difference between sketches, wireframes, mockups and prototypes, and when each one is enough.

Mikołaj Lehman, CEO & Founder, GMI Software
Mikołaj Lehman
CEO & Founder, GMI Software

In brief

A mockup shows product layout, hierarchy and visual direction before expensive implementation starts. This guide explains the difference between sketches, wireframes, mockups and prototypes, and when each one is enough.

A mockup shows product layout, hierarchy and visual direction before expensive implementation starts. This guide explains the difference between sketches, wireframes, mockups and prototypes, and when each one is enough.

A mockup is a visual design, not a working app

A mockup is a static, detailed picture of a future screen. It shows typography, colour, spacing, content, hierarchy and the presentation of key actions. It should not pretend to be a working product: it does not include complete logic, integrations or system behaviour.

A sketch captures an idea quickly. A wireframe organises structure and priorities. A mockup adds visual treatment, while a prototype connects screens into a testable flow. Choose the artefact based on the decision the team needs to make.

What you can validate before writing code

A mockup aligns stakeholder expectations, tests whether the primary action is visible and shows whether real content fits the layout. This is the right moment to reorder fields, shorten a form or remove an element that does not support the user goal.

It does not replace a technical test. If the risk is integration, performance, hardware or data processing, build a proof of concept. If the risk is understanding the end-to-end journey, use a clickable prototype.

  • Information hierarchy and CTA clarity
  • Consistency across views and states
  • User reaction to layout and language
  • Presenting the direction to investors or the team

How not to confuse a polished picture with a finished product

For every mockup, define error, loading, empty-data, permission and small-screen states. Also identify the system of record behind each piece of information. Without this, the design covers only the happy path and pushes difficult decisions into development.

A good process does not end with approving a picture. It ends with validated assumptions, open risks and acceptance criteria. That turns the mockup into a risk-reduction tool rather than decoration.

Related reading

  • Product design and UX/UI

    Discovery, flows, prototypes and validation before expensive implementation.

  • Prototypes and MVPs

    A bounded scope, validation of the critical risk and a plan for the next iterations.

  • Discovery–Design–Technology process

    One decision loop connecting business, design and technology.

Content updated: July 29, 2026

Mikołaj Lehman, CEO & Founder, GMI Software
Mikołaj Lehman
CEO & Founder, GMI Software

Mikołaj Lehman is the CEO and founder of GMI Software. On the blog, he covers decisions around mobile apps, ecommerce and digital product delivery.

  • Mobile apps and React Native
  • Headless and B2B ecommerce
  • MedusaJS
  • Digital product delivery

Google Preferred Sources

See GMI more often in Google

Add gmi.software as a preferred source. Google may highlight our new articles more often in Top Stories and supported AI experiences.

Share article:

Related articles

Product design

Product design vs product development: responsibilities and delivery order

Product design defines the problem, experience and behaviour of a solution. Product development covers building, releasing and operating the full product. Both disciplines need one shared loop.

→
E-commerce

MedusaJS + Next.js for B2B storefronts: architecture, cost and risks

A practical guide to B2B storefronts: MedusaJS v2 as commerce core, Next.js as the buying portal, customer groups, price lists, sales channels, ERP/PIM and implementation cost.

→
Contact

Let's talk
about the project.

Have an app idea or need technological support? Write to us — we'll prepare a preliminary analysis and estimate within 48h. Projects that go through our DDT process (Discovery, Design & Technology) come with a price guarantee and a fixed-price agreement — a key differentiator for us.

Write to us[email protected]
Visit us
GD
gmi.software Sp. z o.o.ul. Jana Heweliusza 11 / 819
80-890 Gdansk, PolandNearshore product delivery across EU, UK and US time zones.
NIP: 5252816287KRS: 0000830003
gmi.
ServicesOur projectsBlogBrief assistantContact
LIFAINGI
Mobile Trends Awards 2025 nomination - SFD app
© 2026 gmi.software Sp. z o.o.
Privacy PolicyTerms