An interface that runs smoothly
A component-based structure makes even complex forms, dashboards and filters fast and logical. Users get their work done with fewer clicks.
React: fast, easy-to-use web applications
We build fast, easy-to-use web applications, self-service portals and SaaS products with React that keep your customers happy and cut manual work for your team. Opus Online is a Tallinn-based software development company with more than 15 years of experience in complex web solutions.
We don’t start from the technology but from your goal. First we find out whether React is the right choice for your project.
Why choose React?
React is the world’s most widely used JavaScript library for building user interfaces, backed by Meta and a large open-source community. For a business, that means three things.
Developers are easy to find
React is the most widely used frontend technology, so your solution doesn’t depend on one person or agency. Your own team can develop the code further later on.
One codebase for web and mobile
The same components and logic can be used in a web application, a React Native mobile app and a Next.js website.
- 25+specialists in our team
- 3+years of React projects
- 6public React references
- ISO 27001certified information security
What we build with React
Self-service portals
Customer and partner portals with contracts, invoices, orders and documents in one place.
SaaS products and web applications
Applications with sign-in, roles, payments and dashboards that grow with your business.
CRMs and internal systems
Admin interfaces with workflows, reports and integrations that replace Excel spreadsheets.
Online stores and headless frontends
A React and Next.js frontend with Magento, Adobe Commerce or MedusaJS.
Mobile apps
React Native apps for iOS and Android that share logic with the web application.
Taking over an existing project
Audit, version upgrades and maintenance for a solution built by another team.
React projects
We have long-standing experience building IT software and online stores for companies from finance to insurance and pharmaceuticals. We are a long-term partner to large corporations and fast-growing startups alike.
Kaupmees B2B online storeA modern B2B online store for Estonia's largest food service supplier: Magento 2 and Next.js, contract prices and fast ordering.Read more
Bonnier Rights Finland: a CRM for selling translation rights with every contract and deadline under controlTranslation rights and contract management with expiry automation, an internal tool for agents.Read more
eTridens B2C online storeA modern B2C online store for a Baltic distributor: Magento 2 and Next.js, a wide range of drinks, food and consumer goods straight to the consumer.Read more
VEHO spare parts ordering systemA Magento spare parts ordering system for a Mercedes-Benz dealer: the right part by product code, real-time stock and payment by credit limit.Read more
Äripäev: a rebuilt news site and custom CMS that is faster and costs several times less to runThe aripaev.ee frontend rebuilt from scratch, a custom CMS for the newsroom and cloud costs cut several times over.Read more
Magnum VET: from phone orders to self-service in five B2B marketsFrom phone orders to self-service: a new B2B ordering platform for veterinary and dental products, five sites in four countries.Read more
TD Baltic: a B2B portal for 2,000+ resellers running directly on the ERPA B2B portal for 2,000+ resellers in the three Baltic states, running directly on the ERP, with self-service reservations.Read more
Automaailm: when speed is of the essenceA car parts store rebuilt from scratch on Magento 2 and React: search, product lists and product pages are now much faster than before.Read more
Is React the right choice for your project?
React isn’t right for every project, and we say so honestly at the first meeting. If search visibility matters most, Next.js is often the better choice, and for a small information site, WordPress.
| Feature | React (SPA) | Next.js (built on React) | WordPress |
|---|---|---|---|
| Best suited for | applications behind a sign-in, portals, dashboards | public sites, online stores, content portals | information and marketing sites |
| Interface interactivity | very good | very good | limited |
| Visibility in Google and AI search | needs extra work | very good | good |
| Integrations (ERP, CRM, APIs) | unlimited | unlimited | limited |
| Initial budget | medium | higher | lower |
| Further development over the years | easy | easy | more complex |
| Editing content | inside the app or with a CMS | with a CMS (Payload, Strapi, Directus) | built in |
Taking over and upgrading an existing React project
We take over React projects built by another agency or an in-house team. We start with a code and security audit, which shows you what is in order, what needs fixing and what is critical.
After the takeover we keep looking after the solution: monitoring, security updates and hosting are part of our maintenance service.
How we work
You talk directly to the people building your solution, not to intermediaries.
Kick-off meeting
We listen to your goals and tell you honestly whether React fits.
Analysis and estimate
Functionality, integrations, risks, timeline and budget.
Development in cycles
A working version every couple of weeks.
Testing and go-live
Speed, accessibility (WCAG, EAA) and security (OWASP).
Maintenance
We stay with the solution after launch too.
Technologies:
- React
- TypeScript
- Next.js
- React Native
- Node.js
- NestJS
- GraphQL
- AWS
Frequently asked questions
How much does a React web application cost?
A React project usually costs between €10,000 and €70,000. A smaller project can cost less and a large platform more, as the price depends on the specifics of the project. We give an exact estimate after a short analysis.
How long does a React project take?
Usually 1–6 months; a larger project can take longer.
Which to choose, React or Next.js?
Next.js is a framework built on React. If the site has to be visible in Google and AI search, we recommend Next.js. For an application behind a sign-in, plain React is often enough.
Is React good for SEO?
Plain React renders content in the browser, so search engines and AI assistants may not see it right away. For public pages we use server-side rendering with Next.js, so the content is visible immediately.
Which backend do you connect a React app to?
Mostly Node.js or NestJS, but also PHP (Laravel, Symfony) and the APIs of existing ERP and CRM systems.
Can you take over a project built by another agency?
Yes. We start with a code and security audit and propose a plan for what comes next.
Where is a React solution hosted?
On AWS or Zone, depending on the load and your requirements.
Get in touch
Planning a new web application, self-service portal or SaaS product, or want to hand over an existing React solution? Write to us, and let’s discuss which solution suits you.
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