Web Application Development

End-to-end SaaS product development from first line of code to production launch. Multi-tenant architecture with row-level security (PostgreSQL RLS) or schema-per-tenant isolation depending on enterprise security requirements. Subscription billing via Stripe Billing: monthly and annual plans, seat-based pricing, usage metering, trial periods, dunning management for failed payments, and proration on plan upgrades. Authentication with NextAuth.js or a dedicated auth service (Clerk, Auth0): email/password, Google OAuth, GitHub, and SAML SSO for enterprise customers. Team management lets users invite colleagues, assign roles, and remove access without engineering involvement. Usage limits enforced at the application layer: API call quotas, storage limits, and seat count checks that degrade gracefully (soft limits with warnings) rather than breaking requests mid-operation. Onboarding flows designed with activation in mind -- the steps between signup and "aha moment" measured and optimised. Admin panel for the customer success team: user lookup, usage inspection, plan override, impersonation for support, and customer communication history. The SaaS product scoped, built, and shipped as a single fixed-cost engagement.

Self-service portals where your customers manage their accounts, view order history, track service status, submit support requests, access invoices and documents, and interact with your business without calling your support team. Real-time status updates via WebSocket or Server-Sent Events so customers see their order moving through fulfilment, their support ticket status changing, or their service being provisioned without refreshing the page. Document access with permission-scoped downloads: a customer sees only their own invoices, contracts, and delivery notes -- not other customers' records, regardless of URL manipulation. Integration with your existing CRM (Salesforce, HubSpot), ERP (SAP, NetSuite, Dynamics), or order management system via REST APIs or event webhooks -- the portal reflects what your internal systems know without a separate data store to keep in sync. Branded to your product with your domain, colours, and typography -- not a generic platform template with a logo swap. Notification preferences let customers choose whether they receive updates by email, SMS, or in-portal notification per event type. The portal that reduces inbound support volume (typical reductions of 30-50% for common enquiry types) while giving customers more transparency than a ticket queue acknowledgement.

Custom internal tools for operations, finance, HR, and logistics teams -- replacing the spreadsheets, shared documents, and manual copy-paste steps that sit between systems that don't talk to each other and accumulate errors proportional to the number of people touching them. Workflow automation built into the application: a supplier invoice arriving by email triggers extraction, three-way matching against the PO and goods receipt, and routes to the appropriate approver based on value and cost centre -- without anyone manually moving data between systems. Role-based access aligned to the org chart: an operations analyst sees the operations queue, a finance manager sees the approvals queue and financial data, an admin sees everything -- with the UI itself adapting to the role so users aren't confronted with sections they can't access. Audit trails for every data change: who changed what, when, from what previous value -- required for finance and compliance and useful for debugging operational errors. Data validation at entry point rather than discovered in month-end reconciliation: duplicate detection, format validation, cross-field consistency rules, and reference data lookups that catch errors when they're cheap to fix. The internal application that makes a specific process measurably faster and less error-prone rather than a generic platform your team builds workarounds for.

Web applications built with a clean API layer designed as a product -- not as internal plumbing that happens to be externally accessible after the fact. API-first means the contract is designed before the implementation: the OpenAPI 3.0 specification defines URL structure, request/response schemas, error formats (RFC 9457 Problem Details), and versioning strategy before a line of code is written. The spec becomes the source of truth that generates server validation, TypeScript types, and interactive documentation rather than drifting from the implementation over time. RESTful API design with resource-oriented URLs, correct HTTP verb semantics, standardised pagination (cursor-based for stability, offset-based where total counts matter), and rate limiting with IETF RateLimit headers so API consumers know their quota on every response. GraphQL as an alternative when multiple client types (mobile, web, partner) need different data shapes from the same API surface -- DataLoader for N+1 prevention, field-level authorisation, and subscription support for real-time data. OAuth 2.0 with appropriate flows per integration type: authorisation code with PKCE for user-delegated access, client credentials for machine-to-machine. Webhook delivery with HMAC signature verification, retry with exponential backoff, and delivery confirmation. SDK generation from the OpenAPI spec produces typed client libraries so integrators use methods rather than raw HTTP.

Web applications with offline capability, push notifications, home screen installation, and native-app-like performance without App Store distribution or user installation friction. The Service Worker API manages the offline experience: a cache-first strategy serves previously loaded pages and assets when connectivity is absent, a network-first strategy fetches fresh content when available and falls back to cache when offline, and a background sync API queues form submissions and data writes for dispatch when connectivity resumes -- so a field worker can complete a data entry form on a construction site with no signal and it syncs automatically when they walk back into range. Browser push notifications via the Web Push API with VAPID keys reach users who aren't actively using the application -- a delivery status change, an approval required, a message received -- without requiring a native app install. Web App Manifest configuration enables home screen installation on iOS (Safari "Add to Home Screen") and Android (Chrome install prompt) so the app launches full-screen without browser chrome, visually indistinguishable from a native app. IndexedDB for structured local data storage that persists across sessions -- more capable than localStorage for complex offline data models. The right choice when your users are on mobile but a full native app build isn't justified yet, or when you want consistent offline behaviour across desktop and mobile from a single codebase.

Data visualisation platforms, reporting dashboards, and operational intelligence tools that pull from multiple data sources and present the information operations and leadership teams need to make decisions -- updated automatically rather than assembled manually from spreadsheet exports. Chart library selection based on the data type: Recharts for time-series and bar charts where React integration matters, Apache ECharts for complex operational visualisations and heatmaps, Mapbox GL JS for geospatial data. Real-time data refresh via WebSocket or Server-Sent Events for operational dashboards where latency matters (fleet tracking, production line monitoring, live order counts); scheduled refresh with configurable intervals for reporting dashboards where near-real-time is sufficient. Filterable views with URL-serialised filter state so a specific filtered view can be bookmarked or shared via link. Drill-down from summary to detail: a total that looks wrong can be clicked to see the constituent records, not just the aggregate. Report export in the format each audience needs: PDF for executive distribution, CSV/Excel for analyst further processing, API endpoint for downstream systems. Role-based visibility controls what data each user sees: a regional manager's dashboard shows their region's data by default, not a global view they must filter down. Performance optimised for large datasets: virtual scrolling for tables with thousands of rows, query result caching with explicit invalidation, and incremental chart updates that replace only changed data points rather than re-rendering the full chart.