Custom Web Applications & High-Scale SaaS Platforms
We architect resilient, ultra-fast web platforms using Next.js 15, React, TypeScript, and microservice backends. Built from ground-zero to handle high concurrent traffic and drive predictable ARR.
What We Build in Web Engineering
From complex multi-tenant B2B architectures to headless digital commerce ecosystems.
Multi-Tenant B2B SaaS Platforms
Scalable software-as-a-service architectures with tenant isolation, tiered subscriptions, billing automation, role-based access control (RBAC), and team collaboration.
- Stripe & LemonSqueezy subscription integration
- Organization management & seat-based licensing
- Isolated Postgres schema / row-level security
Headless E-Commerce & Marketplaces
Ultra-responsive headless commerce with sub-second page loads, dynamic multi-currency checkouts, inventory syncing, and high-conversion product filtering.
- Shopify Plus & MedusaJS headless backends
- Algolia / Meilisearch instant search & filters
- 1-click checkout & automated tax calculations
Real-Time Analytics & Admin Dashboards
Data-intensive executive dashboards capable of visualizing millions of records in real-time with WebSockets, interactive charts, and PDF/CSV reporting.
- High-frequency WebSockets live telemetry
- Apache ECharts & Recharts data visualizations
- ClickHouse & DuckDB analytical queries
High-Throughput REST & GraphQL APIs
High-concurrency API gateways engineered in Node.js, Go, or Python with automated OpenAPI documentation, rate limiting, and enterprise caching.
- Sub-10ms API response times with Redis
- OAuth 2.0, JWT & API Key authentication
- Automated CI/CD contract & regression testing
Progressive Web Apps (PWAs)
Offline-capable, installable web experiences that offer native app capabilities with push notifications, background sync, and instant app store distribution.
- Service Workers & offline indexedDB caching
- Web Push notification infrastructure
- Cross-browser desktop & mobile installability
Legacy Code Modernization & Migration
Refactoring brittle legacy monoliths (PHP, monolithic Rails, jQuery) into modern, modular micro-frontends and serverless Next.js architectures with zero downtime.
- Strangler Fig pattern incremental migration
- Zero-downtime database ETL schema sync
- 400% performance & developer velocity boost
Engineered for Extreme Performance
Every web application engineered by LeadGenIT adheres to modern architectural principles: server components for instant page loads, edge CDN caching, and automated autoscaling.
- Zero Layout Shift: Strict CLS = 0 with optimized font and image loading.
- Type Safety: End-to-end TypeScript from frontend to database ORM.
- Automated Testing: Playwright end-to-end tests + Jest unit suites run on every commit.
- Security Auditing: Strict CSP headers, CSRF tokens, and automated SAST/DAST.
Sprint-Based Web Development Pipeline
We combine agile sprints with CI/CD continuous deployments so you see tangible progress every week.
Discovery & Architecture
We analyze user personas, technical requirements, database schemas, and create the architectural blueprint and interactive wireframes.
Sprint Engineering
2-week agile sprints with working software delivered at every milestone. Clean TypeScript, modular component libraries, and robust API endpoints.
QA & Security Hardening
Comprehensive load testing (k6), automated browser tests (Playwright), cross-device testing, and penetration security scans.
Launch & Hyper-Scale
Zero-downtime blue/green deployment to production cloud, telemetry configuration, and continuous SLA support with performance optimizations.
Web & SaaS Development FAQs
Common questions about timelines, technology choices, intellectual property, and team onboarding.
For modern B2B/B2C SaaS applications, we typically recommend a Next.js 15 (React 19) frontend paired with TypeScript, Node.js or Python backend microservices, PostgreSQL with Prisma ORM, and Redis for high-speed caching. This ensures exceptional SEO, sub-second edge performance, and rapid engineering velocity.
You own 100% of the source code, repositories, intellectual property, design assets, and cloud deployment keys. We transfer complete ownership immediately upon milestone completion.
A fast-turnaround MVP typically takes 4 to 8 weeks, while an enterprise-grade multi-tenant SaaS platform ranges from 10 to 16 weeks depending on third-party integrations, complexity, and custom compliance requirements.
Yes. We have extensive experience integrating modern frontends with legacy SOAP/REST endpoints, on-premise SQL Server databases, ERPs (SAP, NetSuite), CRMs (Salesforce, HubSpot), and custom internal legacy backends.