Custom Web Application Development for B2B SaaS & Internal Tools
Full-stack TypeScript, Next.js, and PostgreSQL web applications engineered in 4 to 12 weeks. Multi-tenant RBAC, enterprise SSO, and 100% Git ownership from €7,500.
Generate a Technical Web App Architecture Brief in 60 Seconds
Share your current website or describe your workflow, user roles, and integrations to receive an instant stack, milestone, and budget breakdown.
What you will receive by email
- Core Web Vitals, mobile speed & render-blocking bottlenecks
- Technical SEO, indexation, hreflang & Schema.org coverage
- Hero clarity, buyer-committee UX & conversion friction points
- Prioritized quick wins & architecture recommendations
No account or email verification code required — submit your URL and our team will send the review directly to your inbox.
Your brief is used solely to prepare your technical estimate and automatically purged after 30 days. NDA available before deep discovery.
Trusted by Venture-Backed SaaS Founders and Enterprise Operations Teams
Production web applications built to handle real transactional concurrency, strict audits, and rapid product iteration.
Vezert's custom web application development service architects and ships B2B SaaS products, multi-tenant portals, and internal operational tools on TypeScript, Next.js, React, Tailwind CSS, and PostgreSQL with RBAC, row-level tenant isolation, SAML/OIDC SSO, Stripe/SEPA billing, WCAG 2.2 AA accessibility, EU cloud residency, and 100% Git ownership.
Clickable Architecture & MVP
4-6 weeks · Figma prototype, Next.js + PostgreSQL, RBAC & CI/CD
Multi-Tenant B2B Platform
6-8 weeks · Tenant isolation, Stripe/SEPA, ERP webhooks & WCAG 2.2 AA
Enterprise Mission-Critical App
8-12 weeks · SAML/OIDC SSO, audit trails & <150ms SQL queries
Outgrown spreadsheets, Bubble, and €80-per-seat bills?
Airtable, Bubble, Retool, and aging PHP monoliths hit a wall once concurrency grows or enterprise security questionnaires arrive.
- Slow queries & no logs: Low-code databases lag at scale and miss immutable enterprise audit trails.
- Gated SSO & seat bloat: SAML/OIDC sits behind enterprise paywalls while per-user fees compound fast.
- Open-ended agency billing: Traditional dev shops burn six months of hourly billing before launch.
Senior engineering with fixed milestones and TypeScript.
We prototype in Figma and ship modular Next.js and PostgreSQL apps proven on Chaindoc and our venture startup builds.
- Multi-tenant security: PostgreSQL row-level isolation, granular RBAC permissions, and SAML/OIDC SSO.
- Billing & ERP webhooks: Automated Stripe/SEPA subscriptions and resilient bi-directional CRM/ERP sync.
- Full Git IP ownership: Weekly staging releases, EU sovereign cloud, and zero per-seat vendor fees.
Our 6-Step Custom Web Application Engineering Process
Weekly working deployments on staging from week two, clear schema contracts, and predictable launch in 4 to 12 weeks.
01. Domain Schema & RBAC Architecture
We map entities, state machines, PostgreSQL tables, tenant boundaries, and external API contracts into a concise technical specification.
02. Clickable UX Flows & Design Tokens
Product designers prototype dense data tables, command palettes, multi-step forms, and approval states in Figma for stakeholder sign-off.
03. Next.js, API & Database Foundation
Engineers stand up monorepo TypeScript types, Prisma/Drizzle migrations, auth/SSO sessions, and automated GitHub Actions CI/CD.
04. Workflow Engine, Billing & Webhooks
We build your core business logic, Stripe/SEPA metered or seat billing, PDF/document pipelines, and resilient ERP/CRM sync queues.
05. Security, Load & Accessibility QA
Every release undergoes cross-tenant isolation tests, OWASP checks, query indexing tuning, and WCAG 2.2 Level AA verification.
06. EU Cloud Launch & Engineering Handover
We cut over with zero downtime, wire Sentry and OpenTelemetry alerts, document architecture decisions, and transfer full Git control.
Production Engineering Capabilities Included as Standard
Built for high-trust B2B transactions, complex data operations, and long-term maintainability.
Row-Level Multi-Tenant Isolation
PostgreSQL RLS policies, organization-scoped workspaces, custom domain routing, and strict tenant boundary tests.
Granular RBAC & Enterprise SSO
Fine-grained role permissions, magic links, MFA, and SAML 2.0 / OIDC federation with Okta, Microsoft Entra ID, and Google.
Stripe, SEPA & Usage-Based Billing
Automated subscription tiers, seat provisioning, EU VAT/invoice generation, SEPA Direct Debit, and webhook reconciliation.
High-Density Operational UI
Virtualized tables, instant multi-column filtering, bulk actions, CSV/XLSX imports, and keyboard-first workflows.
Resilient Queues & Integrations
Idempotent background workers, dead-letter retries, and clean connectors for Salesforce, HubSpot, SAP, Slack, and custom REST/GraphQL APIs.
Immutable Audit Logs & GDPR Controls
Tamper-evident actor logs, field-level encryption for sensitive records, data export endpoints, and automated retention policies.
EU Sovereign Cloud & CI/CD
Reproducible deployments on AWS Frankfurt, Hetzner, Scaleway, or Vercel EU with preview environments on every pull request.
WCAG 2.2 AA & Sub-Second UX
Accessible Radix UI primitives, optimistic UI mutations, server-streamed data, and crisp mobile responsiveness.
Have a Product Spec or Legacy Tool to Replace?
Send your rough user stories or current stack for a fixed-scope milestone plan within 3 business days.
Tailored Architectures for SaaS Products and Internal Operations
Whether you are monetizing a new software product or automating core company operations, we engineer around measurable business outcomes.
Vertical B2B SaaS MVPs & V2 Rebuilds
Turn domain expertise into subscription software with self-serve onboarding, team invites, billing, and tenant analytics.
Transactional & B2B Marketplaces
Multi-party escrow or Stripe Connect payouts, vendor verification, RFQ matching, and encrypted deal rooms.
AI-Enabled Workflow & Copilot Apps
Structured LLM document extraction, RAG search with tenant-isolated vector indexes, and human-in-the-loop review queues.
Customer, Partner & Reseller Hubs
Self-service order configuration, contract e-signing, SLA ticketing, and real-time usage reporting.
Vertical B2B SaaS MVPs & V2 Rebuilds
Turn domain expertise into subscription software with self-serve onboarding, team invites, billing, and tenant analytics.
Transactional & B2B Marketplaces
Multi-party escrow or Stripe Connect payouts, vendor verification, RFQ matching, and encrypted deal rooms.
AI-Enabled Workflow & Copilot Apps
Structured LLM document extraction, RAG search with tenant-isolated vector indexes, and human-in-the-loop review queues.
Customer, Partner & Reseller Hubs
Self-service order configuration, contract e-signing, SLA ticketing, and real-time usage reporting.
No-Code / Retool Stack vs. Vezert Custom Web App vs. Hourly Dev Shop
Compare long-term licensing economics, security posture, performance, and IP ownership.
| Engineering Criterion | No-Code / Low-Code (Bubble, Retool) | Vezert Next.js + PostgreSQL Stack | Traditional Hourly Software Agency |
|---|---|---|---|
| Time to Production V1 | 2 to 5 weeks (hits ceiling fast) | 4 to 8 weeks production-grade | 16 to 32 weeks |
| Per-User / Per-Seat Licensing | €25 to €85/user/month forever | €0 per-seat license fees | €0, but heavy hourly retainers |
| Multi-Tenant Security & SAML SSO | Limited or Enterprise-tier gated | Native PostgreSQL RLS + SAML/OIDC | Custom built over months |
| Query Speed on 100k+ Rows | Sluggish client-side bottlenecks | Indexed SQL + server streaming (<150ms) | Varies by contractor seniority |
| Source Code & Cloud Portability | 100% locked into vendor runtime | 100% owned TypeScript Git repo | Owned, often over-engineered |
| Investor & Enterprise Audit Readiness | Flags technical due diligence | Clean CI/CD, audit logs & WCAG 2.2 AA | Requires separate QA phase |
| Typical Total Cost | €12,000 to €45,000/yr in SaaS seats | from €7,500 fixed milestones | €45,000 to €140,000+ time & materials |
Transparent Custom Web Application Pricing
Fixed EUR milestone packages with weekly staging builds, automated testing, and 100% code ownership.
Not sure whether your scope fits an MVP or a multi-tenant platform?
Share your workflow goals or existing product backlog. Within 3 business days we return a clear entity diagram, milestone breakdown, and fixed EUR quote.
Ship a Production Web Application You Own 100%
Replace brittle low-code tools or launch your B2B SaaS on a clean Next.js and PostgreSQL foundation in 4 to 12 weeks.
Web Application Architecture & SaaS Engineering Guides
Deep dives on custom web app costs, MVP scoping, and multi-tenant Next.js architecture.
Custom Web Application Development FAQs
Straight answers for SaaS founders, CTOs, VPs of Operations, and enterprise IT leaders.