Web Design & Frontend
UX-first design and fast frontend builds without unnecessary bloat.
Click for details →Services
Engineering-led delivery.
Designed for speed and longevity.
SEMLIN builds lean websites, custom backend systems, and specialized crypto solutions. Our default is performance-first engineering — minimal bloat, clean UX, secure architecture.
- Performance-first
- Custom systems
- Security-minded
- Bank • PayPal • Crypto
WebFrontend & UX delivery
BackendAPIs, automation, integrations
CryptoSerious, proof-based support
Our approach
Tools matter, but decision-making matters more. We choose the simplest technology that achieves your goal with speed, stability, and maintainability. That’s why we often avoid heavy page builders and “one-size-fits-all” stacks unless they truly fit your use case.
Use the links below to jump to a service area or open a dedicated subpage.
Service areas
Each service can be expanded into a dedicated subpage when you’re ready.
Backend Development
APIs, integrations, automation, and architecture built for reliability.
Click for details →Web Apps & Custom Systems
SaaS, dashboards, internal tools, portals, user management, billing.
Click for details →Crypto & Blockchain
Wallet recovery (legitimate cases), integrations, smart contract support.
Click for details →Consulting & Architecture
Audits, performance reviews, system planning, CTO-as-a-service.
Click for details →Payments
We accept bank transfer, PayPal, and crypto for suitable projects.
Bank transfer
PayPal
Crypto
Request a quote →
Web Design & Frontend Development
UX-first, performance-driven design and implementation.
Related: Web Apps & Custom Systems · Consulting & Architecture
Overview
We design interfaces that feel modern and load fast. Our priority is clarity: users should instantly understand what to do — and the site should respond immediately.
What we deliver
- Responsive design for mobile, tablet, desktop
- Accessible UI (keyboard, contrast, semantics)
- Modern UI components with consistent spacing & typography
- Performance optimization (assets, rendering, caching)
Tech stack
We start with the web platform — HTML / CSS / JS — and add frameworks only when justified. That keeps payloads small and maintenance simple.
- HTML / CSS / JavaScript
- Modern frameworks when needed (React / Next / Vue, etc.)
- Image optimization, caching, CDN-ready builds
Why we avoid page builders
Many page builders generate heavy markup, large scripts, and inconsistent UI patterns. That often means slower pages, worse UX, and harder maintenance.
When WordPress is acceptable
WordPress can be a fit when a client needs familiar editorial workflows and a simple marketing site. If we use it, we keep it lean: minimal plugins, performance budgets, and clean themes.
Example outcomes
- Faster load times and better Core Web Vitals
- Cleaner UX that reduces friction
- Higher conversion rates from simpler journeys
Backend Development
Custom backend systems tailored to your business logic.
Related: Web Apps & Custom Systems · Consulting & Architecture
Overview
We build backends that are stable under real-world usage: clear APIs, reliable data, and architecture that doesn’t collapse when requirements evolve.
Use cases
- Public and private APIs
- Admin panels and operational tooling
- Automation pipelines and workflows
- Third-party integrations (payments, CRM, analytics)
Architecture & performance
We design around your load profile and constraints, then implement with clarity: caching where needed, efficient queries, and predictable runtime behavior.
- API design and versioning
- Caching & queueing strategies
- Observability (logs, metrics, tracing)
Security & scalability
- Authentication, authorization, roles
- Input validation and secure defaults
- Rate limiting and abuse protection
- Scalability planning (horizontal/vertical)
Databases & storage
We choose storage based on access patterns: relational where correctness matters, document stores where flexibility matters, and object storage for files.
- Relational (PostgreSQL/MySQL)
- Document / key-value when needed
- Blob/object storage for assets
Example systems we build
- API backends for mobile/web apps
- Internal admin + operations tooling
- Data import/export + automation systems
Web Applications & Custom Systems
SaaS, dashboards, portals, and internal tools built to fit your workflows.
Related: Backend Development · Web Design & Frontend
Overview
When your business needs more than a website, we build custom systems that automate work, centralize data, and give teams clarity.
SaaS platforms
- Subscription plans and billing logic
- Usage limits, credits, and feature gating
- Account lifecycle and retention flows
Dashboards & internal tools
- Operational dashboards
- Admin panels & support tooling
- Reporting and exports
Authentication & user management
- Roles and permissions
- SSO when required
- Security best practices
Payments & billing systems
- Stripe / PayPal integrations
- Invoices, receipts, and subscription changes
- Crypto payments where appropriate
Deployment & hosting
We ship with repeatable deployments and clear operational ownership. That includes environments, monitoring, and handover.
Discuss your web app →Crypto & Blockchain Services
Serious technical work — no hype, no shortcuts.
Related: Backend Development · Consulting & Architecture
Overview
We provide engineering support for blockchain-related systems and legitimate recovery scenarios. Everything we do is designed to be ethical, compliant, and verifiable.
Services offered
- Wallet recovery (legitimate cases only)
- Private key reconstruction (proof required)
- Smart contract support and integrations
- Crypto payment integration for websites/apps
Ethical & legal boundaries
- Proof of ownership is required
- No hacking, theft, phishing, or bypassing security
- We reserve the right to refuse any suspicious request
How recovery works (high level)
Every case is different. In general, we start by verifying ownership, then assess what is missing (seed phrase fragments, password patterns, corrupted backups, device constraints), and propose a safe recovery plan.
We do not request sensitive details via email. For sensitive cases we use a controlled process.
Risk disclaimer
Recovery is not always possible. Some methods are probabilistic and depend on the information available. We will explain risks, time expectations, and boundaries before any work begins.
Contact process for crypto cases
- Describe the situation (no private keys)
- We confirm whether the case is eligible
- We agree on a secure information flow
Consulting & Architecture
Expert guidance when you need clarity, not guesswork.
Related: Backend Development · Web Apps & Custom Systems
Overview
If you already have a team or an existing system, consulting can unlock speed and stability fast: we identify bottlenecks, reduce risk, and help you make high-leverage decisions.
When consulting makes sense
- Projects are slowing down or getting unstable
- You need a clear architecture direction
- Costs are rising without clear results
- Security/performance concerns appear
Tech audits
- Codebase review and risk assessment
- Dependency and architecture sanity checks
- Actionable roadmap (what to fix first)
Performance audits
- Core Web Vitals and runtime profiling
- Backend latency and query efficiency
- Caching and delivery strategy
Architecture planning
- System design sessions
- Data model and API planning
- Deployment strategy and environments
CTO-as-a-service
Ongoing technical leadership for founders and teams: architecture decisions, hiring guidance, review processes, and practical execution support.
Talk to us →Want a clear quote and plan?
Tell us your goal, deadline, and constraints. We’ll propose a lean, realistic approach.