Vetted engineers with verified commercial track record in Next.js
Khmelnytskyi, Ukraine
Full-Stack Developer, Fractional CTO — Websites, Apps, Servers, Databases, AI, SEO & QA
Full-stack developer working across the entire stack — websites, apps, servers, databases, AI integrations, SEO, and QA. Languages & Core: writes code in JavaScript, TypeScript, Python, PHP, Go, and Rust. Architects scalable systems for large-scale projects. Frontend & Interfaces: builds websites and web applications with React and Next.js. Crafts responsive interfaces with Tailwind CSS, Radix UI and Shadcn, adds smooth animations with Framer Motion, and interactive charts with Recharts. SEO Audit & On-Page Optimization: semantic keyword research, resolving technical indexing issues, and optimizing page load speeds. Structures page architecture, meta tags, and multi-language support (i18n). Copywriting & Content Strategy: writes technical articles, drafts precise content briefs for writers, and develops content plans. QA & Testing: full-cycle testing for websites, web services, and Android apps — manual QA for UI/UX and business logic, plus automated testing with Jest, Vitest, Playwright and E2E. Backend, Cloud & Databases: complex API integrations of any scale. Builds servers with Node.js (Express, Fastify). Works with PostgreSQL, MySQL and MongoDB, ORMs (Prisma, Drizzle), and cloud infrastructure (Supabase, Firebase, Cloudflare). Browser Extensions & Automation: develops Manifest V3 browser extensions for Chrome, Edge, Firefox and other browsers. Builds web scrapers for complex data extraction using Puppeteer and Playwright. AI & Intelligent Agents: builds custom AI agents and integrates LLMs from OpenAI, Google Gemini, and Anthropic Claude via API, including Claude Code setups. Servers & DevOps: Linux (Ubuntu) and VPS administration — setup, updates, real-time monitoring, secure process isolation, Nginx, PM2, and CI/CD deployment via GitHub Actions. Telegram Bots: develops advanced Telegram bots (Telegraf, Grammy) integrated with AI, payment gateways, Google Sheets, and crypto exchanges. Desktop Applications: builds cross-platform software for Windows and macOS using Electron and Rust. Additional expertise: site development and customization with WordPress and Astro.
Senior Frontend Engineer · React · Next.js · Angular | Open to new opportunities
Senior frontend engineer with deep experience across React, Next.js and Angular, building enterprise dashboards and complex UI systems. Strong focus on performance, component architecture and design-to-code fidelity.
Mügeln, Saxony, Germany (Saxony, Germany · Remote)
Full-Stack Engineer — TypeScript, React, Next.js, Node.js, PostgreSQL | Germany
Full-Stack engineer with 13+ years of technical experience, including 7+ years directly managing and administering production databases. Specializes in PostgreSQL relational schema modeling, slow-query optimization (EXPLAIN ANALYZE), relationship design, and data integrity via Prisma ORM and raw SQL. Designed a real-estate platform syncing 50K+ records in PostgreSQL and serving them through ~100 API endpoints.
London, United Kingdom (London, United Kingdom · Hybrid)
Full-Stack AI Product Engineer | ex-CTO Pineapple Builder | PostgreSQL & Relational Architecture
Full-Stack engineer and ex-CTO of the Pineapple Builder platform with 11+ years of commercial experience. Personally designed and led the PostgreSQL relational database architecture for a full-featured site builder, ensuring high content throughput via a GraphQL API. As Member of Technical Staff at DevRev, built the Agent Studio agentic platform core and agent connections to tools and databases.
London, United Kingdom (London Area, United Kingdom · Remote)
Full Stack Engineer | ReactJS, NextJs, NodeJS, TypeScript, AWS & Java | Contractor
Senior Full-Stack contractor and solutions architect with 10+ years of commercial experience in FinTech, Buy Now Pay Later (BNPL), and e-commerce. At Deko, led the build and launch from scratch of an instalment fintech platform with £1.3M turnover. Designed a JavaScript plugin system for merchant site integrations based on React, Next.js, GraphQL, and Storybook, plus serverless backend infrastructure on AWS (Lambda, SQS, SNS).
London, United Kingdom (London Area, United Kingdom · Remote)
Principal Engineer | Senior Frontend Developer | React.js · Next.js · Tailwind CSS · GraphQL | Headless E-Commerce Specialist
Lead frontend architect with 10+ years of commercial experience building complex user interfaces and headless e-commerce platforms. At Chalhoub Group designed and shipped a modular reusable-component library on React.js and Tailwind CSS, reworked checkout and cart to lift conversion, and optimized interface performance and response times on mobile devices. Extensive experience with testing (Jest, React Testing Library), GraphQL (Apollo Client), and CI/CD pipeline setup.
London, England, United Kingdom (London, United Kingdom)
Senior Software Engineer at On | Full-Stack & Backend Systems Architecture
Senior Full-Stack engineer and consultant with 8+ years of commercial experience designing and scaling high-load digital platforms. Lead engineer at Swiss-British sports brand On, responsible for designing and scaling the customer profile platform. Deep expertise in TypeScript, React, and Node.js microservice architecture, technical interviewing, and adopting AI tooling in development.
London, United Kingdom (London, United Kingdom · On-site / Remote)
Senior Front End / Full Stack Developer contractor with Next.js, React.js, TypeScript, PostgreSQL & Supabase
Senior full-stack contractor in London with deep commercial experience building high-load frontends and backends on React, Next.js (App Router, React Server Components, Server Actions), TypeScript, and Supabase. At EdenMarsh independently delivered a turnkey MVP web platform for a well-known marketing agency with a PostgreSQL database on Supabase, analytics dashboards, and Vercel deployment. At uXentrik Ltd develops the OpenBody 3D platform on Next.js, Three.js, and Supabase Postgres DB.
London, United Kingdom (London Area, United Kingdom · Hybrid)
Forward Deployed Engineer @ Stripe | Developer, Visiting Instructor, Mentor
Stripe team engineer (Forward Deployed Engineer at Stripe). Works directly with key business clients on architecture and delivery of complex payment solutions: Stripe Connect marketplaces, multi-currency billing, complex payment pipelines. Deep background in full-stack development (React, Next.js, Node.js, Python, GraphQL).
AI Product Architect | I help founders design & launch scalable AI SaaS platforms — fast, secure, production-ready
AI product architect helping founders design and launch scalable AI SaaS platforms, from architecture and security to production-ready deployment.
London, United Kingdom (London Area, United Kingdom · Remote / Hybrid)
Senior React Native & Full-Stack Engineer | Supabase, Next.js, PostgreSQL | AI Pipelines & TypeScript
Senior full-stack engineer with 6 years of commercial experience who launched 20+ production systems for 600K+ users. Specializes in building web and mobile systems on Next.js, React Native, and Supabase (PostgreSQL, pgvector, realtime sync, Row Level Security). Designed the LeftOverChef platform with a monorepo architecture, RAG pipelines, and a Supabase backend. Built offline-first Argonaut and Auro apps with reliable data sync via Supabase workflows.
Khmelnytskyi, Ukraine
Frontend Developer | React, Next.js, TypeScript | SSR, CMS & Shopify
Frontend developer specializing in server-side rendered React and Next.js applications, headless CMS integrations and custom Shopify storefronts for e-commerce clients.
Founder betterwrite.io | Frontend Developer | Modder | Writer
Frontend developer and founder of betterwrite.io, an AI writing assistant product. Combines product-building experience with strong technical writing, from UI implementation to shipping features end-to-end.
London, United Kingdom (London Area, United Kingdom)
Senior Full Stack Engineer at Marcura | PostgreSQL & Python/Node.js Specialist
Senior Software Engineer with extensive experience optimizing and scaling relational databases under high loads. At Marcura and ARTERA, responsible for designing data-storage structures in PostgreSQL and MySQL, removing query bottlenecks, configuring connection pools, and scaling cloud database instances on AWS RDS.
London / Croydon, England, United Kingdom (London, United Kingdom)
Frontend Developer | React | TypeScript | Tailwind CSS | Next.js
Frontend engineer specializing in the modern React.js, Next.js (App Router, Server Components), and Tailwind CSS stack. Author of open learning projects and interactive AI apps (Memory Palace, Christmas Photo, Frontend-30). Deep hands-on experience building responsive, accessible interfaces with the Tailwind ecosystem: Shadcn UI, Radix UI, and Framer Motion.
Buenos Aires / Remote (international Vercel team)
Forward-Deployed Engineer at Vercel | GitHub Star | v0 Ambassador | Next.js & Tailwind Specialist
Lead engineer at Vercel (Forward Deployed Engineer and Solutions Architect). Official v0 ambassador (Vercel's generative AI tool for building UI with Tailwind CSS and Shadcn UI) and GitHub Star recipient. 5+ years at Vercel advising global enterprise clients on frontend-architecture optimization, Next.js rendering, and scaling Tailwind CSS styles. Contributed to the Next.js Commerce reference repositories.
Khmelnytskyi, Ukraine
React Frontend Developer | React, Next.js, React Native | Crafting Pixel-Perfect, High-Performance Web & Mobile Apps
React frontend developer crafting pixel-perfect, high-performance web and mobile applications with React, Next.js and React Native. Focused on smooth UI, tight design fidelity and responsive layouts.
London, United Kingdom (London, United Kingdom)
Software Engineer (AI & Full Stack) | React · Node.js · FastAPI · Python | LangChain · RAG · Agents | PyData London & LangChain London Speaker
Full-stack AI engineer with a master's degree in Computer Science (Machine Learning & AI specialization, GPA 4.0). Builds the full AI product stack: from React frontends and FastAPI/Node.js backends to RAG pipelines and production multi-agent systems. Worked as an engineer at DXC Technology and Alankrita, designing agent orchestration architecture, evaluation (evals) frameworks, and context engineering. Regular speaker at the PyData London and LangChain London communities on production AI agent reliability.
Next.js has become the enterprise standard for React applications, but navigating App Router paradigms requires deep understanding of server vs client component boundaries. Digital agencies routinely quote $150 to $250 per hour while assigning developers who treat Next.js like a traditional single-page application, causing massive bundle sizes and slow initial loads.
Working directly with an independent Next.js specialist gives you immediate collaboration with an engineer who understands Vercel infrastructure, React Server Components (RSC), and edge caching.
| Evaluation Criterion | Traditional Web Agency | ProofDevs Independent Senior |
|---|---|---|
| Hourly Rate | $150 – $250 / hr | $50 – $100 / hr |
| Next.js Expertise | Often legacy Pages Router or SPA paradigms | Deep App Router, Server Actions & caching expertise |
| Contractual Minimum | Multi-week onboarding retainers | None (book a 4-hour fix or weekly sprint) |
| Direct Access | Project managers and ticket queues | Direct pull requests and technical discussion |
| Code Ownership | Restricted access until final signoff | 100% private Git repo commits on day one |
The majority of Next.js App Router issues stem from multi-tiered caching: the Request Memoization layer, Data Cache, Full Route Cache, and Router Cache in the browser. Developers frequently struggle when dynamic user data is inadvertently cached across users or when stale data persists after mutations.
Senior Next.js developers master cache revalidation strategies using `revalidatePath`, `revalidateTag`, and dynamic rendering flags (`export const dynamic = 'force-dynamic'`).
Furthermore, hydration mismatches — caused by date formatting differences, invalid HTML nesting, or reading `window` on initial render — are resolved at the root cause rather than suppressed with `suppressHydrationWarning`.
Senior Next.js developers optimize web performance by enforcing proper font preloading with `next/font`, responsive image optimization with `next/image`, and dynamic imports for heavy client libraries.
Architecture Rule: The Client Component Leak
Marking a parent component with 'use client' automatically forces all imported children to execute in the client bundle. Senior Next.js developers pass Server Components as children/props to Client Components, preserving zero-bundle-size server execution.
Engagement timelines depend on codebase complexity and dependency versions.
Independent Next.js engineers charge between $50 and $100 per hour. You retain 100% ownership of all repository commits, Vercel/cloud deployment keys, and environment variables upon milestone approval.
Teams adopting Next.js usually weigh the App Router, the legacy Pages Router, a plain Vite SPA, and Astro against SEO pressure, team skill, and hosting budget. The App Router with React Server Components gives the fastest public pages on Vercel. The Pages Router suits teams with existing getServerSideProps code. SPAs fit private dashboards, while Astro wins for content sites with light interactivity.
Cache behavior decides more than rendering labels suggest, so quantify before migrating. Public pages should hold LCP under 2.5 seconds with ISR revalidation windows matched to content freshness, such as 60 seconds for listings. Apps with per-user data on every screen gain little from static caching and pay App Router complexity tax. Maintenance cost drops when server boundaries stay disciplined and client components stay small.
| Option | Rendering and cache model | Ecosystem and upkeep | Pick it when |
|---|---|---|---|
| App Router 14/15 | RSC plus Data, Route, and Router caches; ISR support | Vercel-native; cache debugging skill needed | SEO apps, SaaS marketing plus product |
| Pages Router | getServerSideProps and getStaticProps | Mature guides; larger hiring pool | Existing codebases, teams mid-migration |
| Vite SPA plus API | No server rendering; client fetch | Simplest upkeep; needs SEO workarounds | Private dashboards, internal tools |
| Astro 4/5 | Static output plus islands; minimal JS | Small React surface; fewer backend patterns | Docs, blogs, landing pages |
Many production apps still run Pages Router with getServerSideProps on every page, oversized _app bundles, and JavaScript files without types. A senior engineer migrates incrementally: new routes ship in the App Router beside legacy pages, shared UI moves into Server Components, and data fetching shifts to cached Server Actions with Zod validation. Both routers serve traffic until metrics prove the new routes.
Phased rollout keeps risk contained because old pages stay live behind the same domain. Phase one, Next.js 14/15 upgrade with codemods and type baselines, takes 8 to 16 hours. Phase two, migrating 5 to 10 routes with revalidateTag contracts and Playwright checks, takes 25 to 60 hours. Phase three, bundle cleanup with next/bundle-analyzer and Lighthouse 95+ on mobile, takes 10 to 20 hours per batch.
Taking over a buggy Next.js app starts with cache forensics, not rewrites. The client provides repository access, Vercel project logs, a list of stale-data complaints, environment variable samples, and the three most painful incidents. A senior engineer then traces revalidation paths, reproduces hydration mismatches locally, audits client bundle weight with next/bundle-analyzer across key routes, and carefully reviews full Server Action error handling.
Some Next.js codebases cost less to rebuild than to repair, and flagging that early saves budget. Red flags include every page forced server-rendered with no caching strategy, client components importing entire chart libraries at the root layout, and Server Actions mutating data without validation. A scoped rebuild of the worst routes, 30 to 60 hours, beats endless cache patches. Most other apps stabilize within 10 to 25 hours.
Audit rule: fix versus rebuild
Rebuild only when repair exceeds replacement: all routes server-rendered with no cache plan, root layouts pulling heavy client libraries, or mutations without validation across the app. Otherwise commission a 4-hour audit delivering a ranked defect list with hour estimates per fix.
Strong Next.js candidates draw cache diagrams from memory: where Request Memoization ends, what revalidateTag invalidates, and why a page rendered stale data. Junior signals include sprinkling use client everywhere, fetching inside effects instead of Server Components, and silencing hydration warnings. Ask how they cut a bundle from 500 kB to 180 kB and listen for route-level numbers with server boundaries intact.
A paid trial of 3 to 5 hours separates cache experts from template users. Provide a route with stale Server Action data, a hydration mismatch from locale dates, and an oversized client bundle. Acceptance criteria: fresh data after mutation with tests proving it, zero hydration errors in production build, measurable bundle reduction, and a short note outlining cache contracts they would document with 10 more hours.
You will receive matches with available senior Next.js engineers within 2 to 4 hours of submitting your requirements.
Rates range from $50 to $100 per hour, based on expertise in App Router, Server Actions, performance tuning, and Vercel infrastructure.
Yes. Our engineers specialize in diagnosing App Router cache layers, eliminating hydration mismatches, and restoring expected server action behavior.
Yes. Profiles specify whether engineers maintain legacy Pages Router codebases or architect greenfield App Router applications.
You own 100% of all Git repositories, branch commits, and deployment configurations upon milestone signoff.
Pick the App Router for SEO pages and new SaaS builds, stay on the Pages Router while a large codebase migrates incrementally, and use a Vite SPA only for private dashboards. A 2-hour cache and rendering review settles the choice with LCP targets attached.
Most work lands between 4 and 60 hours: hydration and cache triage takes 4 to 12 hours, Core Web Vitals tuning 8 to 20 hours, and Pages-to-App Router migrations 25 to 60 hours. Matching takes 2 to 4 hours and quotes list fixed hours upfront.
Yes, when routes build on Next.js 13+ and data flow is traceable through Server Components and Actions. You provide repo access, Vercel logs, and stale-data examples; a 4-hour audit returns ranked fixes. Apps with zero cache strategy across every route may rebuild worst routes in 30 to 60 hours.
Run a paid 3 to 5 hour trial at $50-$100/hr: fix a stale Server Action, resolve a locale-date hydration mismatch, and shrink an oversized client bundle. Pass bar is fresh post-mutation data with tests, zero hydration errors in production build, and a smaller bundle.
Repository access, Vercel project access or deploy credentials, env variable samples, content freshness rules per route, and analytics or Search Console data. With that bundle the engineer ships the first fix the same day matching completes, typically 2 to 4 hours after your request.
Every engagement includes a 2-week defect window covering regressions from delivered work at no extra charge. Most clients then keep 5 to 10 hours per month at $50-$100/hr for revalidation monitoring, dependency upgrades, and Lighthouse 95+ re-checks.
Yes. Engineers configure preview deployments per pull request, environment promotion, and rollback runbooks, usually 3 to 6 hours of setup. You keep full ownership of the Vercel project, domains, and secrets from day one.
