Services
Custom software development company in Ukraine
EVA-X is a custom software development company in Kyiv. We design and build the systems a business runs on — web platforms, mobile apps, CRMs, marketplaces and the integrations between them — for a fixed price agreed before work starts.
You don’t buy hours from us. You describe the product, get an estimate in about 15 seconds, and our team reviews it with you before a contract fixes the scope, the price and the payment schedule. The code is written by our own engineers, with AI where it speeds the work up and never where it would cut corners.
When the contract is paid in full, the rights to the code pass to you.
- Price
- Fixed after scoping
- Payments
- By stage, held until you accept
- Team
- Our own engineers, Kyiv
- Contract
- Signed online, scope locked
Custom software development
What we build
Business platforms
Web systems with roles, cabinets and permissions: client portals, partner and staff platforms, B2B services.
Mobile apps
iOS and Android apps from one codebase with React Native and Expo, on the same backend as the web.
CRM and internal tools
Pipelines, documents, approvals and reports built around how your team already works — not the other way round.
Marketplaces and storefronts
Catalogues, search, payments, orders and the back office that keeps them running.
AI features
Assistants and analysis that answer from your own data, show their sources and stay inside clear limits.
Integrations
Payments (Stripe, WayForPay), email, maps, auction and marketplace feeds, accounting and the APIs you already use.
How it works
From a brief to an accepted product
The same five steps for every project, whatever we build. You always know what is agreed, what is paid and what is done.
Estimate
Describe the product in your own words, add a link or a file. In about 15 seconds you see the modules, the hours, the timeline and a price.
Team review
Our team reads the brief and the estimate, asks about anything unclear in your cabinet or on a call, and confirms the scope and the price. Nothing starts before that.
Contract
You sign a contract online: a fixed price, the scope split into modules, and a payment schedule — in full or by stages.
Milestones
We build module by module. QA checks each one before it reaches you, and the cabinet shows the work as it moves.
Acceptance
You have 7 days to review each module: accept it or send it back with a list of fixes. Your money stays in the project reserve until you accept.
Three formats
Choose how we build it
The format decides who writes the code and how much engineering review goes into it — and with that, the price and the pace.
- AI / build
AI Build
Fastest path · prototypes & internal tools
AI generates the structure and most of the implementation. Engineers review integrations and the release. The lowest cost, for prototypes, internal tools and MVPs that test an idea.
- AI / engOur pick here
AI + DEV
Recommended for most MVPs
AI builds the scaffolding and the obvious parts. Engineers own the architecture, critical logic, integrations and full QA. Balanced pace and review, for customer-facing MVPs and B2B products.
- full / eng
DEV
Maximum quality & control
Senior developers own architecture and implementation end to end. AI is an internal tool for speed, never the final author. For production systems and regulated domains.
For most custom software we recommend AI + DEV: AI speeds up the routine parts, and engineers own the architecture, the business logic and QA. Choose DEV for regulated or high-load systems where every line needs a senior author, and AI Build for an internal tool you need next week.
Cases
Work that proves it
BIBI CARSbibicars.bg / crm & storefront / 2026Car import from US and Korean auctions, end to end
Read the case →
ECO.NOVAb2b / operations platform / 2026Hazardous waste disposal as a transparent B2B service
Read the case →
LUMENfintech / web3 / 2026Fractional investment in real-world assets
Read the case →FAQ
Questions we get asked
How much does custom software development cost?
It depends on the modules, not on a rate card. The estimate on our site breaks your product into modules with hours and gives a price in about 15 seconds; our team then confirms the scope and the price before the contract. Once the contract is signed, the price is fixed: it doesn’t grow with the hours we spend on the agreed scope.
Do you work at a fixed price or time and materials?
Fixed price. Every project has a contract with the scope split into modules, a price and a payment schedule. If you want something new halfway through, we agree it as a change request with its own price and timeline, and you approve it before we start on it.
Who will write the code?
Our own team in Kyiv: employees and contractors bound by confidentiality and IP obligations. We don’t resell projects to subcontractors. How much AI is involved depends on the format you choose — AI Build, AI + DEV or DEV.
How do payments work?
You pay in full or by stages, by card or bank transfer. Payments go into the project reserve and are released module by module, only when you accept a module. The cabinet always shows what is paid, what is released and what is held.
Who owns the code?
You do, once the contract is paid in full; the contract can also transfer the rights module by module as each one is paid. They cover the source code, designs and documentation made for your project.
What happens after launch?
Every accepted module comes with a warranty: unless the contract says otherwise, we fix reproducible defects in our code reported within 30 days of acceptance, free of charge. New features go through a new estimate or a change request in the same cabinet.
Do you work with companies outside Ukraine?
Yes. Contracts are signed online, prices are usually set in US dollars, and you can pay by card or bank transfer. BIBI CARS, for example, imports cars to Bulgaria.
Services
Related services
- Web application developmentClient portals, B2B platforms, SaaS and dashboards — and the fast public sites in front of them.
- Mobile app developmentiOS and Android apps on React Native and Expo, with the backend and admin behind them.
- CRM and internal systemsDeal pipelines, documents, client cabinets and reports, built around the process your team actually runs.