Custom web development for modern businesses
Modern websites and web apps built by senior developers — fast, responsive, easy to manage. Integrate AI agents, copilots, or data when you need them; ship a great website even if you don’t.
Sanity
Contentful
WordPress
Optimizely
Adobe
Shopify
Development Solutions
Responsive websites
Modern responsive websites for promo, corporate, and e-commerce — fast, accessible, easy for your team to manage. SEO-optimized, conversion-tuned.
UI/UX design
Both UI and UX play a key role in our process. UX ensures functionality and intuitive user journeys; UI focuses on visually appealing, user-friendly interfaces. Together they deliver a seamless experience that’s practical and a joy to use.
E-commerce & landing
High-performance e-commerce and landing pages with conversion-focused design, payments, analytics, and AI personalization or recommendations when your roadmap calls for it.
Modernization & migration
Rebuild legacy sites on a modern stack — better performance, better SEO, better content workflow. AI capabilities ready for day one if you want them, or simply a faster, cleaner site if you don’t.
Technical stack
Web
Contentful
Sanity
WordPress
Optimizely
Adobe
Magnolia
Shopify
Magento
Webflow
Back-end
Node.js
Nest.js
Express
PHP
Python
ASP.NET
Django
Flask
Ruby on Rails
Sinatra
C#
Symfony
Laravel
Yii
Go
Erlang
C/C++
Scala
Rust
Julia
R
AI
OpenAI GPT
Llama
Anthropic
Gemini
Hugging Face
Tensorflow
PyTorch
OpenCV
DeepSeek
Qwen
LangChain
LangGraph
Don’t see the tech stack you are looking for? No worries!
Our team has experience finding candidates for custom requirements and various tech stacks. Please contact us, and let’s find you a perfect candidate.
Our engineers developed products for
Project Stages and Flow
We run every project through Production-Ready AI Engineering — senior engineers and AI agents in the same delivery loop, with evals and human review built in.
Initial stage
We ensure your project’s success with careful planning. During the initial stage, we collaborate with you to align functionality, performance, and design. We define strategy, set priorities, and establish your budget and deadlines before starting work.
Design stage
After developing a prototype wireframe, our design team starts to create your application style (the app’s “look and feel”). In this stage, we provide you with a full set of UI screens to use for further development.
Development stage
Product development progresses through multiple releases, including an MVP. We use Agile sprints to speed up the process, running development alongside wireframes, documentation, and mockups.
Ongoing development, support, and maintenance stage
After releasing the MVP, our team performs new sprints to speed new releases with additional functionality. And we support and maintain the latest version of the launched app.
Development Formats and Billing
Monthly Team Allocation
The best products require experimentation and iteration. With Monthly Team Allocation, you reserve a dedicated squad. You get:
- A senior team that’s always yours, never reassigned mid-project
- Scope and priorities you can flex sprint by sprint
- Predictable monthly spend with no padding for risks you may never use
- Velocity from a team that already knows your codebase
Agile
Agile software development involves a series of short sprints to ensure rapid, transparent progress toward your product goals. We apply this nimble, responsive approach to incorporate your feedback, adjust priorities as needed, and ensure your approval at every step. We use the Agile best practice because it is more flexible—and less risky—than the linear Waterfall development methodology.
We offer 2 approaches
to developing your project
Project
development
Project development provides a fully dedicated team to bring your vision to life, ensuring seamless delivery and alignment with your goals.
Benefits of Working with Diffco
Senior teams, no junior bench
Senior engineers from day one. The engineer who scopes the work is the engineer who ships it.
Streamlined Development Process
Agile project management will keep you in the loop, providing useful feedback during every iteration of your project.
Transparent Billing
You will always know what to expect and never face any surprises in the billing department. Understand your charges, both what you’re paying for and why.
Clear Communication and Detailed Reporting
From the moment we first connect to the moment we deliver exactly what you need, you’ll have all the information you need to keep your finger on the pulse of your project.
Success stories of our clients
We launched an e-commerce platform and custom loyalty solution for next-generation pipe brand
We've delivered a powerful corporate website for the enterprise segment
The Diffco team studied FlashGrid’s product and marketing strategy to make sure all of our requirements were addressed.
We’ve created a web platform and ERP solution for a new generation real estate service for retail businesses
We have delivered an AI tool that simplifies writing tasks through personalized guidance
We’ve delivered a convenient website with an amazing atmosphere of ‘escape’ rooms
We created a platform for professionals and beginners in the aviation industry
We developed a promo website and a custom booking system for discovery flight provider
Led Core Platform Development & Supported Product Growth Through Seamless Operations
We’ve delivered an advanced ERP system for service centers
We developed an e-commerce platform and ERP for premium lighting solution vendor
We launched an e-commerce platform and custom loyalty solution for next-generation pipe brand
We've delivered a powerful corporate website for the enterprise segment
The Diffco team studied FlashGrid’s product and marketing strategy to make sure all of our requirements were addressed.
Explore our
amazing case studies
Frequently Asked Questions
Frequently Asked Questions
What is custom web app development?
Custom web app development is engineering bespoke web products — from corporate sites and e-commerce platforms to dashboards and AI-native applications. At Diffco every web project starts with discovery, then we ship under Production-Ready AI Engineering: senior engineers and (when relevant) AI agents in the same delivery loop. The result: web products that look modern and actually work.
How much does it cost to create a custom web app?
We run on Monthly Team Allocation — one predictable monthly fee for a dedicated team that’s always yours. Scope and priorities flex sprint by sprint. No padding for risks you won’t hit. See our blog for the full breakdown.
How long does custom web application development take?
Discovery: 1–2 weeks. PoC: 2–4 weeks. MVP: 6–12 weeks. Full product: 2–3+ months for typical web; 3–4+ months for AI-heavy builds. Production-Ready AI Engineering lets us ship in weeks what most teams scope in months — without giving up production-grade quality.
Do you build websites without AI features?
Yes — most of our web engagements are classic corporate, e-commerce, and SaaS sites. AI is available when your roadmap calls for it; not required.
Which CMS do you recommend?
It depends on team and budget. Sanity or Contentful for modern headless setups. WordPress for content-heavy sites with broad in-house editor needs. Shopify or Magento for e-commerce. Optimizely or Adobe for enterprise. We pick during discovery.
Do you handle SEO and analytics setup?
Yes. Technical SEO (schema, sitemaps, performance, Core Web Vitals) and analytics setup (GA4, Mixpanel, Segment, Plausible) are standard on every launch.
Can you migrate from one platform to another?
Yes. We’ve migrated sites from WordPress to Webflow, from Magento to Shopify, from custom platforms to Contentful — without losing SEO, content history, or traffic.
Do you offer ongoing content management support?
Yes. After launch we offer ongoing content, SEO, and feature support under Monthly Team Allocation. Most clients keep a small ongoing engagement post-launch.
Let’s build something
great together.
Need other services?
Team Augmentation
We provide engineers or teams tailored to your project, ensuring skill and compatibility with your goals and culture. They will collaborate with you closely, infusing fresh energy and ideas.
Back-end Development
We are experienced in high-load and complex backend infrastructure development for mobile or web apps and enterprise services.
Front-end Development
We are experienced in building modular, high-performance web applications for corporate clients and startups. We utilize modern and robust technology stacks.
Mobile Development
We specialize in developing native and cross-platform mobile applications for iOS and Android.
