# Web & Mobile Development

URL: https://momentaj.com/services/web-mobile-development/
Updated: 2026-10-09
Category: Engineering
Provider: Momentaj Inc., Toronto AI engineering firm; remote across Canada, the United States and the Middle East, in person across the Greater Toronto Area

Fast, accessible web apps and mobile-first PWAs in Blazor, SvelteKit and React, designed with the people who will use them.

At a glance:
- Web apps and installable PWAs, bilingual and right-to-left where needed
- Design and prototyping with real users before the build
- Component systems: our own YeSvelte, Blazor, Tailwind
- Accessibility and performance measured, not claimed

Momentaj, a Toronto AI engineering firm, designs and builds web apps, mobile-first PWAs and the interfaces of AI products. The interface is where an AI system earns or loses trust: the card that shows what the agent found, the approval step before it acts, the search box that answers in the user's language. We design and build those interfaces, and the ordinary web and mobile products around them.

## What we build

- **Web applications.** Customer-facing and back-office apps in Blazor, SvelteKit or React, with TypeScript and Tailwind.
- **Mobile-first and PWA.** Installable progressive web apps that behave like native apps, including bilingual and right-to-left layouts. Native iOS and Android where the product needs it.
- **Design.** User research, journeys, wireframes and prototypes, tested with real users before anything is built. Design systems your team can extend.
- **AI interfaces.** Chat with cards and quick replies, generative UI, approval flows and the states an agent-driven interface needs: thinking, asking, acting, failed.
- **Embeddable components.** Search boxes and widgets packaged as web components so they drop onto any page.

## How it's done

Start with the people who will use it: research and journeys first, then a prototype tested with real users before anything is built. Mobile-first and a PWA by default, native iOS or Android only where the product needs device capabilities a PWA cannot reach. The framework is the one your team can maintain, and accessibility and performance are measured rather than assumed.

## Proof

[MayAI](https://momentaj.com/case-studies/mayai/): a mobile-first PWA in English and Arabic. [YeSvelte](https://momentaj.com/case-studies/yesvelte/): our open-source Svelte component library with swappable themes. [Trip Support](https://momentaj.com/case-studies/trip-support/): a bilingual search web component used across a marketing site.

## Frequently asked questions

**Do you still build native mobile apps?** Where the product needs device capabilities a PWA cannot reach. For most products a mobile-first PWA ships faster, costs less to maintain and installs without an app store.

**Which frameworks do you use for web and mobile apps?** Blazor, SvelteKit and React. We choose what your team can maintain, and for AI products the interface is designed around the model's replies, not a chat box added to an existing app.

**Do you build interfaces for AI products?** Yes. MayAI's mobile-first chat app is built in SvelteKit, and DevGuardian AI's review interface in Blazor.

**How do you handle web accessibility and performance?** We measure both rather than assume them, and we do user research before the build so the interface fits the people who will use it.

**How much does web or mobile app development cost?** Each stage has its own price, agreed before it starts, rather than a published rate card, because the cost depends on your workflows, your data and the systems in scope. Discovery is a fixed price based on the number of workflows and systems in scope, and each later stage is quoted before it begins.

**Do you work with companies outside Toronto?** Yes. We work remotely with clients across Canada, the United States, the Middle East and beyond, and in person across the Greater Toronto Area.