Sub-second LCP
Real-user Core Web Vitals are tracked from staging onward. We refuse to ship a new feature that regresses LCP, INP or CLS budgets.
Services
Custom Web Application Development Services for SaaS and Enterprise
YuSMP Group is a custom web application development company for US and EU teams building SaaS products, B2B portals, and customer-facing platforms. We ship TypeScript codebases on Next.js, NestJS, .NET, and Python — engineered for Core Web Vitals, accessibility, and audit-ready scale. GDPR-aligned, SOC 2 Type II in progress, HIPAA-capable engineering across regulated workloads.
We design and build production web applications end to end — multi-tenant SaaS, B2B and customer portals, internal admin platforms, marketplaces, and headless commerce front ends. Our senior engineers work in TypeScript on Next.js and React for the front end, NestJS, .NET, and Python on the server, with PostgreSQL, event-driven services, and cloud-native delivery on AWS, Azure, and GCP. Every engagement covers discovery, UX, architecture, accessibility (WCAG 2.2 AA), performance budgets, observability, and post-launch evolution — so the product scales past launch instead of stalling at MVP.
What you get with YuSMP web development
Design-system-first
A typed component library, tokens and Storybook are foundation work, not afterthought, so your tenth feature ships as fast as your second.
Secure by default
CSP, SRI, signed cookies, OWASP top-ten reviews and dependency policies. No "we will harden later" tickets in our backlog.
i18n out of the box
ICU messages, locale-aware routing and right-to-left support are wired in from sprint one for products that target multiple US & EU markets.
WCAG 2.2 AA
Accessibility checked on every PR with automated and manual tests. EU Accessibility Act 2025 readiness is part of our definition of done.
AI-assisted UX
Where it pays off, we add inline AI search, smart forms or copilots, governed by clear prompts, evals and human-in-the-loop fallbacks.
Technology stack we use
React
Next.js
Vue
Nuxt
TypeScript
Node.js
NestJS
.NET 8
Laravel
PostgreSQL
MongoDB
Redis
Vercel
AWS
Storybook
Playwright
How we deliver — discovery to production
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01
Discovery
We map user journeys, traffic shape and SEO goals, then agree on performance budgets, browser matrix and accessibility targets up front.
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02
Design
UX flows, design tokens and a component contract are built before feature work, so frontend and backend stay in sync from sprint one.
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03
Build
Two-week sprints, preview deployments per pull request, automated visual regression and Lighthouse gates on every merge to main.
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04
Run
Real-user monitoring, error budgets and quarterly performance audits keep the app fast and accessible long after launch day.
Engagement models
Fixed Price
For marketing sites, portals and bounded SaaS modules with crisp scope, fixed launch date and pre-defined design system.
Time & Materials
For evolving SaaS where roadmap shifts every quarter. Senior squad, weekly reporting, monthly capacity reviews.
Dedicated Team
Long-term frontend or full-stack squad embedded in your product organization, owning specific surfaces of the application.
Selected web work
Real US & EU-aligned web platforms we have shipped — SaaS, B2B portals, trading venues and analytics consoles.
Home Improvement · Web
Mosokna
Unified online window calculator and CRM — address-based lookup, multi-tenant Laravel + React engine powering three brand sites.
Home Renovation · Web
FinishRemont
Redesigned, SEO-optimized Tilda website for an apartment renovation and design company — portfolio, blog, video, lead capture.
Sports Media · Mobile
Media Arena
Cross-platform sports news app and web portal — Telegram-bot CMS instead of a custom admin, Markdown publishing pipeline.
Industries we build web platforms for
From regulated FinTech consoles to patient portals meeting GDPR + HIPAA bars — we build web that meets US & EU compliance bars without sacrificing user experience.
FinTech
Trading venues, neobanking dashboards, KYC portals and embedded finance — PCI DSS, PSD2, MiCA and DORA aligned.
Web fintech →HealthTech
Patient portals, telemedicine, EHR front-ends and clinical SaaS — GDPR, HIPAA-capable, MDR and ISO 13485-aware delivery.
Web healthtech →E-commerce & Retail
Headless commerce, marketplaces, B2B portals and omnichannel storefronts with US & EU consumer-law-aligned checkout.
Web commerce →Logistics & Mobility
Dispatcher consoles, TMS portals, fleet visibility dashboards and shipper APIs aligned with US & EU mobility frameworks.
Web logistics →Performance, accessibility and US & EU web standards
Modern web is judged by Core Web Vitals on real devices, by WCAG / EU Accessibility Act / US ADA conformance, and by GDPR/ePrivacy + CCPA on every interaction. We treat all three as launch criteria.
Core Web Vitals as a budget
LCP under 2.5s, INP under 200ms, CLS under 0.1 — budgeted at design time, measured with real-user monitoring and gated in CI on every release.
WCAG 2.2 AA & EU Accessibility Act
EU EAA 2025 turns accessibility from nice-to-have into legal baseline. Axe, screen readers, keyboard-only flows tested before each release.
GDPR + CCPA & ePrivacy
Consent-mode patterns, server-side tagging where feasible, region-locked analytics by default (EU-only for EU traffic, US-region for US traffic). No third-party scripts run before consent; DPAs in place for every vendor.
eIDAS (EU) + NIST SP 800-63 (US) — digital signatures
Qualified electronic signatures and eIDAS-compliant identification flows for the EU; NIST SP 800-63 / E-SIGN Act / UETA-aligned identity proofing for the US. Audit-grade trails for documents, contracts and onboarding on both sides of the Atlantic.
Cyber Resilience: NIS2 (EU) + NIST CSF (US)
Hardening web platforms against NIS2 (EU) and NIST Cybersecurity Framework / CISA guidance (US) — vulnerability disclosure, incident response, supply-chain controls and SBOMs for delivered code, with SOC 2 Type II evidence collection (in progress).
i18n & multi-locale
i18n-first routing, content models per locale, hreflang and locale-aware Open Graph — designed for English (US/UK), German, Dutch, French, Swedish and beyond from day one.
Why US & EU teams pick YuSMP
GDPR-aligned · ISO 27001 ready · SOC 2 Type II in progress · HIPAA-capable · CCPA-acknowledged
Aligned across CET & ET time zones
Designers, frontend and backend on a CET workday with East-Coast US overlap (9 AM–1 PM ET). No 14-hour review cycles, no async-only delivery.
Senior-only engineering
We pair a tech lead, senior frontenders and a UX engineer on every web build. No bench juniors hidden behind invoices.
GDPR + CCPA & ISO 27001 ready
EU hosting · US options on request, region-locked analytics, consent-mode by default. ISO 27001 controls with SOC 2 Type II in progress; PCI DSS available where checkout is in scope; HIPAA-capable for healthcare surfaces.
For checkout, wallet and BNPL surfaces we operate inside PCI DSS scope and align with your acquirer and QSA on tokenization, logging and CSP rules.
Frequently asked questions
How do you choose the technology stack for a new web application?
We pick the stack against three constraints: the workload, the team that will own it after handover, and the regulatory profile. For most US and EU clients that means TypeScript on Next.js for the front end, NestJS or .NET for the API, and PostgreSQL with a managed cloud platform. We deviate to Python when data, ML, or analytics workloads dominate. The decision is documented in an architecture brief before a single line ships.
How do you guarantee Core Web Vitals and front-end performance?
Performance is a contract, not a polish phase. We set LCP, INP, and CLS budgets in the architecture brief, enforce them in CI with Lighthouse and bundle-size checks, and use Next.js primitives — image, font, partial prerendering, and edge runtime — to hit them. Real-user monitoring (Vercel Analytics, Sentry, or Datadog RUM) runs from day one so regressions surface within hours, not after a customer complaint.
Do you build to WCAG and other accessibility standards?
Yes. Every interface we ship is built to WCAG 2.2 AA by default, which also covers the EAA 2025 requirements for EU operators and ADA expectations in the US. We use accessible component libraries (Radix, shadcn/ui patterns, React Aria), run axe and Pa11y in CI, and validate keyboard, screen reader, and reduced-motion flows during QA. VPATs and accessibility statements are available on request.
How do you scale a SaaS web app as customer count grows?
We design for horizontal scale from the start: stateless services behind a managed gateway, PostgreSQL with read replicas and connection pooling, Redis for hot paths, queues for asynchronous work, and a CDN-fronted front end. Autoscaling targets, SLOs, and a load-test baseline are part of every SaaS engagement, so the platform absorbs growth instead of being rearchitected at series B.
Which multi-tenant architecture do you use for SaaS?
There is no single right answer — we pick per workload. Shared database with row-level security (Postgres RLS) is our default for cost efficiency and fast tenant onboarding. We move to schema-per-tenant when reporting and per-tenant backups dominate, and database-per-tenant for regulated workloads — HIPAA, financial, or data-residency-bound — where isolation and BAA scope outweigh operational cost. The decision is documented and reversible.
What are typical timelines and pricing for a web application engagement?
A focused MVP runs 60,000 to 180,000 EUR over 12 to 20 weeks. Full SaaS platforms and enterprise portals start at 250,000 EUR and scale with scope. We engage fixed-scope, time and materials with a cap, or dedicated team — most US and EU clients prefer T&M with a cap for predictability without losing flexibility. A ballpark estimate lands within three business days of the first call.