Custom Web App Development
CoreLine builds custom web applications for product teams that need more than templates. SaaS platforms, internal tools, customer portals, and data-intensive dashboards - designed, built, and shipped by senior engineers who own delivery end-to-end.
SaaS & Platforms
Multi-tenant architecture
Subscription and billing
API-first design
Internal Tools
Admin dashboards
Workflow automation
Reporting and analytics
Customer Portals
Self-service interfaces
Account management
Real-time data views
Sound familiar?
You've outgrown your no-code or low-code platform and need a real engineering team
Your web app needs to handle complex business logic that off-the-shelf tools can't support
Previous agencies delivered a demo, not a production system - you need it done right this time
Your team has domain expertise but needs a development partner to build the product
Every web app engagement starts with scope definition and architecture. We ship working software every two weeks, with CI/CD and production observability from sprint one.
We define the data model, API surface, authentication, and infrastructure before writing application code. You approve the architecture before development begins.
Two-week sprints with demo and review. Frontend and backend work in parallel against locked API contracts. Every PR passes automated testing and senior code review.
Production deployment with monitoring, error budgets, and performance baselines. Post-launch we support scaling, feature development, and infrastructure optimization.
Delivered outcomes
Using solutions such as React Native, Flutter, AWS, and many others makes it possible for us to upgrade your product as much as possible and to achieve a thriving collaboration. Here you will find our guide through our most used technologies and case studies related to each one.
AWS offers the tools to build powerful, flexible, and scalable applications, from compute and storage to databases and content delivery.
Simply put, Flutter is Google’s cross-platform framework that lets you build mobile, web, desktop, and embedded apps, all from a single codebase.
React Native is Facebook’s cross-platform framework that combines the best of React with native platform features - perfect for new projects or enhancing existing ones.
Other technologies we use
Frequently asked questions
Primary stack: TypeScript, React, Next.js for frontend; Node.js, Python, Go for backend; PostgreSQL and Redis for data; AWS and GCP for infrastructure. We choose the stack that fits the product requirements, not the other way around.
Yes. We regularly join existing projects, audit the codebase, and extend functionality. If the existing architecture is sound we build on it; if it needs improvement we propose specific changes with clear rationale.
We model domain logic explicitly using patterns appropriate to complexity: service layers for straightforward CRUD, domain-driven design for complex multi-entity workflows. Business rules are testable, documented, and separated from infrastructure concerns.
Scoped engagements start at 8-12 weeks of senior engineering time. We publish a fixed scope and timeline at discovery. Ongoing partnerships run on monthly retainer with prioritized backlog and weekly demos.
You do. Code, repositories, infrastructure configuration, and data are yours from day one.
