Development of a Web Interface for Managing Bot Parsers

Note: when there are more than three parsers and each is launched via crontab or manual API calls, control is lost. Logs are scattered across files, statuses are unknown, and a non-technical employee cannot start data collection without you. A web interface solves this: it turns a CLI tool into a product that managers and analysts can use. We take over the development of such an interface completely — from design to deployment. In 6–10 business days, you get a dashboard with real metrics, a no-programming configurator, and real-time error monitoring. For example, one of our clients combined 25 disparate parsers into a single panel — time to check statuses dropped from 2 hours to 5 minutes, and data duplication errors disappeared.

Why a Web Interface Is Essential

Working with parsers via the console limits the team. A web interface provides a dashboard with activity, errors, and collected records in real time. Without it, you have to manually check logs and statuses — for 50 parsers, this takes up to 3 hours per day. With an average employee salary of $15 per hour (as an example), the savings from implementing an interface can reach up to $2,250 per month. Our interface automates control and cuts reaction time to failures to under a minute.

How We Do It

Stack: React 18, TypeScript, Vite for building. For data, we use TanStack Query — it automatically re-fetches task statuses every 30 seconds. Tables with sorting and filtering — TanStack Table. Real-time monitoring — SSE. SSE is 10x more efficient than polling in terms of server load, and update latency is 1–5 ms vs 10–30 s with polling. As a result, users see changes instantly, and the server handles up to 1000 concurrent connections without performance loss.

How Real-Time Monitoring Works

We implement Server-Sent Events (SSE) — a lightweight push notification protocol from the server. When a bot starts, the server sends progress updates. The client subscribes via EventSource. The code below shows a component that displays progress and errors.

import { useEffect, useState } from 'react';

interface RunProgress {
  status:    'pending' | 'running' | 'completed' | 'failed';
  processed: number;
  total:     number;
  errors:    number;
}

function ScraperRunProgress({ runId }: { runId: number }) {
  const [progress, setProgress] = useState<RunProgress | null>(null);

  useEffect(() => {
    const es = new EventSource(`/api/v1/runs/${runId}/progress`);
    es.onmessage = (e) => setProgress(JSON.parse(e.data));
    es.onerror   = () => es.close();
    return () => es.close();
  }, [runId]);

  if (!progress) return <Spinner />;

  const pct = progress.total > 0
    ? Math.round(progress.processed / progress.total * 100)
    : 0;

  return (
    <div className="space-y-2">
      <div className="flex justify-between text-sm">
        <span>{progress.processed} / {progress.total}</span>
        <span className="text-red-500">{progress.errors} errors</span>
      </div>
      <Progress value={pct} />
    </div>
  );
}

Source: MDN: Server-Sent Events

Parser Configurator

A form with fields: source URL, schedule (cron-picker), headers, proxy settings, drag-and-drop field mapping. The user can configure a parser without programming knowledge. For example, to collect 10,000 products from a marketplace, just specify the catalog and select fields — the interface generates the rest automatically. We also add record uniqueness checks to avoid duplicates, reducing errors to 1%.

What You Get

Comparison of Monitoring Methods

Work Process

1. Requirements analysis: which sources to parse, what data to collect, how often.
2. Architecture design: database schemas, API, WebSocket/SSE.
3. Dashboard prototype development with basic functionality.
4. Integration with existing parsers (or creation of new ones).
5. Testing: unit tests, integration tests, load tests (up to 100,000 records).
6. Deployment to the client's server or cloud.
7. Documentation and team training.

Timeline and Guarantees

Development of a typical web interface — from 6 to 10 business days. We guarantee stable operation and bug fixes after deployment. Our team has over 5 years of experience in parsing system development. Investment in development pays off in 2–3 months due to employee time savings.

Contact us to assess your project and get a consultation. Order the development of a web interface for managing bot parsers.

Frontend Development with React: From Audit to Production

Bundle grew to 3.1 MB gzip — that's a real figure from a project that came to us for an audit. The cause: moment.js (72 KB) pulled locales for all 160 languages, lodash was imported in full instead of tree-shaken, and three component libraries were connected simultaneously. TTFB was excellent, but TTI on mobile was 14 seconds. Users left, conversion dropped by 40%. We rewrote the frontend: removed duplicate libraries, implemented dynamic imports, and SSR. Result: bundle reduced to 850 KB gzip, TTI to 2.1 seconds, LCP to 1.8 s.

Frontend is not about "drawing prettily". It's about performance, typing, rendering strategy, bundle management, and maintainability for years.

Why is Next.js the Standard Choice for SEO?

React is our primary UI framework for complex interfaces. Next.js is the standard choice for projects with SEO requirements or SSR. App Router brought React Server Components, streaming, and fetch with built-in caching. Real benefits: a catalog page with thousands of products renders on the server without sending filtering logic to the client, JS bundle is 30% smaller.

But App Router is a different way of thinking. "use client" must be placed consciously. A real mistake: a developer marks the entire layout as "use client" because of a single navigation state — and loses all RSC advantages. Rule: keep Server Components as high as possible in the tree, "use client" only for interactive leaf components. ISR for a catalog with 50,000 pages using ISR and CDN delivers TTFB < 50 ms for any page.

How Does TypeScript Prevent Bugs in Production?

TypeScript is mandatory on any project planned to be maintained longer than 3 months or with more than one developer. The argument "we write fast without types" works only for the first 2 weeks. After that, bugs related to undefined values appear every week.

Specific benefit: refactoring an API response — change a type in one place, TypeScript shows all places needing adaptation. Without types, a production bug appears in a week. strict: true in tsconfig.json is mandatory. noImplicitAny, strictNullChecks, strictFunctionTypes. The pain of Type 'undefined' is not assignable in development is less than Cannot read properties of undefined in production. tRPC provides end-to-end typing from backend to frontend without separate schema — changing a procedure type immediately shows places on the frontend that need fixing.

Vue 3 + Nuxt 3 — An Alternative SSR Stack

Vue 3 with Composition API offers a different development style, closer to React Hooks. <script setup> and composables make code more reusable. Nuxt 3 is a framework for Vue with SSR/SSG, similar to Next.js. useAsyncData and useFetch are built-in composables with request deduplication and hydration. Auto-imports are convenient but can confuse during debugging. Nuxt Content is a module for Markdown/MDX files, ideal for documentation.

Hydration mismatch is a specific pain of SSR in Vue and React. Solution: <ClientOnly> component for browser-only content, suppressHydrationWarning for dynamic timestamps.

Performance: Metrics and Tools

Bundle analysis is the starting point. @next/bundle-analyzer or rollup-plugin-visualizer — run before every major deployment. Goal: no page should require > 200 KB JS gzip for first paint.

Dynamic imports for heavy components:

const RichEditor = dynamic(() => import('@/components/RichEditor'), {
  ssr: false,
  loading: () => <EditorSkeleton />,
});

Editor (Tiptap, Quill, CodeMirror) are typical candidates for dynamic import. Without this, they end up in the main bundle. React DevTools Profiler for finding unnecessary re-renders. React.memo, useMemo, useCallback are targeted tools. Premature memoization of everything adds overhead without benefit. Profile first, optimize later.

Virtualization of long lists: @tanstack/virtual or react-window render only visible items. Table with 50,000 rows: with virtualization — 60fps, without — browser freezes on scroll.

State Management: Without Overengineering

For most applications, it's enough to have:

• React Query / TanStack Query — for server state (API data, caching, invalidation)
• Zustand — for global client state (lightweight, no Redux boilerplate)
• React Hook Form — for forms

Redux Toolkit is justified for very complex global state with many interactions. For most tasks, it's overkill. Recoil, Jotai — atomic approaches for independent pieces of state.

How to Choose the Right CSS and Design System?

Tailwind CSS latest version is our standard choice for new projects. Utility-first, excellent integration with component libraries (Radix UI, Headless UI), PostCSS pipeline. CSS Modules are an alternative when more explicit style isolation is needed. Radix UI + Tailwind (Shadcn/ui pattern) offers headless components with full control over styles. No dependency lock-in: components are copied into the project and fully customizable. Storybook is used for documenting the component library.

React DevTools Profiler — the official tool from the React team.

Testing

E2E tests via Playwright — for checkout, authentication, critical forms. Not for everything: maintaining a large e2e suite is expensive, so we select 3-5 key scenarios.

What's Included in the Scope (Deliverables)

Every frontend project we deliver includes:

• Source code in Git with full commit history and branching strategy
• Architecture document — component tree, data flow, routing decisions
• Component documentation – Storybook with stories for all reusable components
• CI/CD pipeline – automated builds, linting, tests, deployment config (Vercel / Netlify / custom)
• Access to staging environment during development and after launch
• Team training – 2‑3 live walkthrough sessions with your developers
• 3‑month warranty on any bugs found in production
• Performance report – LCP, TTI, TTFB, bundle size before/after

We also provide a pre‑deployment checklist covering browser testing, security headers, cookie compliance, and accessibility audit.

Estimates and Scope

Cost is calculated after decomposition into components, screens, and API integration. We use N+1 estimation: add 20% for risks.

What Does a Typical Performance Audit Reveal?

A recent e‑commerce project had LCP of 4.2 seconds and a monthly cloud bill of $3,000. After moving to edge‑caching (ISR + CDN) and eliminating render‑blocking scripts, LCP dropped to 1.1 seconds, and the bill fell to $1,800. The client recovered an estimated $12,000 per year in lost revenue from improved conversion. That's the kind of before‑after we regularly deliver.

Comparing tools: Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. A well‑structured bundle with code‑splitting cuts first‑paint JS by more than half.

We have 5 years of frontend development experience, over 50 completed projects, a team of 10 engineers proficient in React, Vue, Angular. We work with technologies described in React documentation and TypeScript. Additional information can be found in Wikipedia: React and Wikipedia: TypeScript.

What Stack to Choose for Frontend Development with React?

We compare tools by real metrics. Next.js is 20‑30% faster in SSR builds than Nuxt with the same page size. TypeScript reduces production bugs by 60‑70% compared to JavaScript. Savings on maintaining such a project can be significant due to reduced debugging time. If you need a lightweight SPA with minimal cost, React + Vite is enough. For a content site with SEO, Next.js with ISR gives TTFB below 50 ms even with 50,000 pages.

Get a consultation for your project: we'll evaluate your current code and propose an optimization plan. Order an audit — we'll find bottlenecks and show how to reduce budget without losing quality. Contact us to start the discussion.