APPcustom web application development

Custom web application development with a public side that ranks.

Custom web application development at Founcy Solutions starts from one observation: every web app is two products. The workflow behind the login has to be fast, secure and easy to use. The public routes (pricing, docs, listings, templates) have to be server-rendered so search engines and AI assistants can read them. We engineer both from one codebase.

Scope my web app → See the rendering map

code in your repository
a rendering plan per route
performance budgets in CI

app.architectureillustration

public routes: server-rendered, cached at the edge, indexable
app routes: behind login, roles checked on every request
sitemaps and structured data generated from the database

public server-renderedprivate behind loginone codebase

definition

What is custom web application development?

Custom web application development is the design and engineering of browser-based software around one organisation's workflows, users and data, instead of bending an off-the-shelf SaaS tool to fit. It covers discovery, UX, architecture, front end and back end, integrations, authentication and roles, testing, deployment and iteration. A well-built custom app also decides which of its pages are public, so pricing, documentation and listings can be indexed while everything behind the login stays private.

Best for: Workflows SaaS can't model, new products that need an MVP, and teams outgrowing spreadsheets
Architecture: A modular monolith first; separate services only where load or teams demand it
Rendering: Public routes server-rendered or static; the app itself client-rendered behind the login
Ownership: Code, pipelines and cloud resources live in your accounts

sound familiar?

You've outgrown the workaround.

Pick the ones that apply. They travel with you into the project brief.

Tap anything that sounds familiar.

what's included

Custom web app development services, from brief to backlog.

Six workstreams run through every build. How deep each one goes depends on your users, your data and your risk.

Discovery brief

User stories, acceptance criteria and the success metrics the app will be judged against, agreed before anyone writes code.

Prototype first

UX flows and a clickable prototype your real users test, so the expensive mistakes happen on screens, not in sprints.

Architecture & rendering map

Data model, integrations and a rendering decision for every route: static, server-rendered or client-side.

Auth, roles & audit

Single sign-on, role-based access control and audit logging designed into the data model from the first sprint.

Public SEO layer

Metadata, XML sitemaps, JSON-LD and canonical rules generated from your data, so public pages stay accurate as records change.

Quality gates in CI

Automated tests plus performance and accessibility budgets that block a release before users or crawlers notice a regression.

public surface

Your app has a public surface. Most builds forget it.

Pricing, docs, templates and listings are where new users find you. Here's what changes when the team building the app also answers for its search visibility.

public pages indexed: by accident

Public routesClient-rendered, so crawlers receive an empty shellServer-rendered or pre-rendered, readable without JavaScript

App routesLogin screens and app shells leak into search resultsKept out of the index on purpose with robots and noindex rules

Deleted recordsA "not found" message served with a 200, read as a soft 404A real 404 or 410 status, so dead pages drop out cleanly

Structured dataNone, or hand-pasted and out of dateSitemaps and JSON-LD generated from the database on every change

PerformanceMeasured once, at launchCore Web Vitals budgets (LCP ≤ 2.5s, INP ≤ 200ms, CLS ≤ 0.1) enforced in CI

OwnershipCode and hosting in the vendor's accountsRepository, pipelines and cloud resources in yours

Why server-render? Google describes dynamic rendering as a workaround, not a long-term solution, and Vercel's analysis of crawler traffic found the major AI crawlers don't execute JavaScript.

how it works

Working software, every sprint.

You see the product take shape in demos, not status reports. Each phase hands you something you can test.

01
Discover
Workshops with the people who will use the app, to map workflows, edge cases and the numbers that define success.
→ discovery brief
02
Design
Prototype, architecture and rendering map, with a phased estimate that separates the MVP from everything after it.
→ approved prototype + estimate
03
Build in sprints
Short iterations against a shared backlog, with a working demo at the end of each and your feedback steering the next.
→ demo every sprint
04
Harden & launch
QA, security and load testing, a pre-launch check of public routes and Core Web Vitals, then a staged rollout.
→ launch runbook
05
Support & iterate
Monitoring and fixes, then a roadmap shaped by how people actually use the app, not by the original spec.
→ usage-led roadmap

stack

Chosen for your team, not our habits.

We pick the stack your team can hire for and maintain after handover.

// front end

TypeScriptReact / Next.jsVue / NuxtAngularBlazor

// back end & data

.NET 10 / ASP.NET CoreNode.jsPostgreSQLSQL ServerRedis

// apis & identity

RESTGraphQLOpenAPIOAuth 2.0 / OIDCWebhooks

// delivery

DockerKubernetesGitHub ActionsAzure DevOpsPlaywrightLighthouse CIOpenTelemetry

keep exploring

Often built alongside.

PRT

Customer portals

Self-service portals for customers, partners or staff, with role-based views.

Explore → API

API-first backends

Contract-first APIs your app, partners and mobile clients can rely on.

Explore → MOD

Modernise an existing app

Re-platform a legacy system in stages, without a risky big-bang rewrite.

Explore → CLD

Cloud-native architecture

Containers, serverless and edge delivery designed for uptime and cost.

Explore →

faq

Custom web app questions.

The biggest drivers are the number of user roles and workflows, how many systems you integrate (and how good their APIs are), security and compliance requirements, and design complexity. Data migration, hosting and support are separate lines. A phased MVP lowers the upfront cost, and a fixed estimate follows discovery.

It depends on scope. An MVP limited to the core workflow ships much sooner than a full platform. Discovery produces a sprint-level plan, and you see working software in demos throughout, so the timeline is never a surprise.

Buy for commodity functions like email, payroll or a basic CRM. Build when the workflow is what sets you apart, when seat fees and workarounds keep piling up, or when you need to own the data. Most teams land on a hybrid: build the differentiating layer and integrate the rest.

Its public routes will be. They're server-rendered or statically generated, with metadata, sitemaps and structured data generated from your data and Core Web Vitals checked before launch. Pages behind the login don't need indexing and are excluded on purpose.

The code lives in your repository and the infrastructure in your cloud account from day one, with documentation written so any competent team can pick it up. Ownership and IP terms are set out in the contract before work starts.

Yes. We put model calls behind your own service layer so you can switch providers, keep sensitive data out of prompts, log usage, and cap costs with caching and rate limits.

Usually a well-structured modular monolith first. It's faster to build and easier to change. We split out services only where independent scaling, deployment or team ownership justifies the extra operational cost.

start your app

Tell us what your app needs to do.

Share your site and a line about the workflow. We'll come back with questions, a rendering map for your public routes and a phased plan.

quote within 24 hours · code in your repository · public routes built to be found