Vetted engineers with verified commercial track record in Node.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.
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).
Tallinn, Estonia
Founder / Senior software developer
Founder and senior software developer building SaaS products end-to-end, from architecture and backend APIs to the shipped frontend. Focused on lean, maintainable systems for early-stage products.
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).
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.
CTO at Peppernode | Empowering Startups with Cutting-Edge SaaS & Food Tech Solutions
CTO at Peppernode, building SaaS and food tech solutions for startups, from product architecture to engineering team leadership.
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.
Boston, Massachusetts, United States (Boston, Massachusetts, United States)
Software Engineer at Stripe | Full Stack Web Developer
Software engineer at Stripe. Builds reliable full-stack solutions focused on user experience and critical payment-infrastructure stability. Also does independent web development for businesses, applying modern tech standards, transaction security, and automation.
Geelong, Victoria, Australia (Geelong, Australia · Remote)
Lead Shopify Developer | Shopify Plus, Custom Apps & Subscriptions | 6+ Years Building Bespoke E-Commerce at Agency Level
Lead developer at the Haydon Power agency (Shopify Experts). Owns architecture and delivery of complex bespoke stores for international merchants. Works across the full platform stack: custom Liquid themes, admin and checkout extensions (Shopify Checkout & Admin Extensions), Shopify Functions, Node.js backend, and embedded custom apps. Previously spent about 4 years building storefront solutions at German e-commerce company Tante-E.
Full Stack Developer | Backend Developer | Software Developer | AI Developer
Full stack developer covering backend services and frontend delivery, with growing specialization in integrating AI features such as classification and retrieval into product workflows.
Klaipeda, Lithuania (Klaipeda, Lithuania · Remote)
Senior Software Engineer at valantic LT | Stripe Certified Associate Developer | Certified Magento Developer | 6+ Years in Web Development
Certified Stripe developer (Stripe Certified Associate Developer) and Senior Software Engineer with 6+ years of commercial e-commerce experience. Specializes in integrating Stripe payment modules into online stores and enterprise web apps, designing secure transactional backends in Go, PHP, and Node.js, optimizing PostgreSQL databases, and Docker containerization.
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, 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.
Node.js drives high-concurrency microservices and real-time backends, but building resilient asynchronous architectures requires senior engineering experience. Traditional IT staffing agencies bill $140 to $230 per hour while delegating tasks through account executives and delivery managers.
ProofDevs connects you directly with independent senior Node.js specialists who profile event loop latency, structure type-safe backend services, and deploy production containers at transparent rates between $45 and $95 per hour.
| Staffing Criterion | IT Staffing Agency | ProofDevs Independent Senior |
|---|---|---|
| Hourly Rate | $140 – $230 / hr | $45 – $95 / hr |
| Technical Vetting | Keyword resume filtering by recruiters | Code audits and production track-record verification |
| Minimum Retainer | Mandatory multi-month retainers | Zero retainers: book by exact task or sprint |
| Communication Path | Client → Account Rep → Project Manager → Developer | Direct technical collaboration with the engineer |
| Code Ownership | License restrictions until contract completion | 100% private Git repo commits on day one |
Node.js achieves high throughput through its single-threaded non-blocking event loop. However, inexperienced developers frequently block the event loop with synchronous operations, heavy JSON parsing, or unindexed database queries, causing all concurrent requests to freeze.
Senior Node.js engineers structure backends using asynchronous streams (`stream.pipeline`), worker threads for CPU-bound computations, and backpressure management to handle massive data uploads without exhausting process memory.
They also diagnose memory leaks by analyzing V8 heap dumps and garbage collection logs, eliminating uncleaned event listeners and unbounded cache growth.
Senior Node.js developers write type-safe TypeScript backends using Fastify, Express, or NestJS, enforcing strict payload validation and automated testing.
Architecture Rule: The Event Loop Starvation Trap
Running synchronous CPU-heavy algorithms or unconstrained JSON operations on the main thread blocks Node.js from processing incoming I/O events. Senior engineers offload compute-heavy tasks to worker threads or background message queues (BullMQ/RabbitMQ).
Historical project benchmarks for standard commercial Node.js tasks.
Independent Node.js engineers charge between $45 and $95 per hour. You retain 100% intellectual property ownership of all source code, Docker configs, and deployment scripts upon milestone approval.
Teams choosing a Node.js backend usually weigh Express, Fastify, NestJS, and Hono against hiring budget, throughput targets, and long-term upkeep. Express offers the largest middleware ecosystem and lowest hiring friction, while Fastify delivers higher JSON throughput with schema validation built in. NestJS adds opinionated structure for large teams, and Hono targets edge runtimes with a small footprint for APIs serving thousands of requests per second.
Throughput differences only matter past clear thresholds, so measure before committing. A JSON API under 2,000 requests per second runs well on any option, while services above 10,000 requests per second benefit from Fastify validation and keep-alive tuning. Maintenance cost rises with NestJS decorators and module wiring, which pays off for teams above six engineers but slows solo founders working against tight release deadlines.
| Option | Throughput and performance | Ecosystem and upkeep | Pick it when |
|---|---|---|---|
| Express 4.x/5.x | ~8k-12k JSON req/s per core; maturity over raw speed | Largest middleware catalog; hires in days | CRUD APIs and admin tools where hiring speed matters |
| Fastify 5.x + Ajv | ~20k-30k JSON req/s per core with schema validation | Smaller plugin set; stricter contracts, fewer runtime surprises | High-throughput JSON APIs above 10k req/s |
| NestJS 10/11 | Express/Fastify under the hood; ~5-10% decorator overhead | Opinionated modules; heavier upkeep, clearer boundaries | Teams of 6+ engineers on long-lived services |
| Hono 4.x on edge | Low cold-start; tuned for edge and serverless | Young ecosystem; fewer adapters | Edge endpoints, Cloudflare Workers, tiny services |
Many production systems still run Express 3.x handlers in plain JavaScript with callback nesting, CommonJS requires, and untyped request payloads. A senior engineer starts with a strangler pattern: new endpoints ship as TypeScript Fastify or NestJS services behind the same API gateway, while legacy routes stay live. Shared behavior moves behind versioned contracts, so old and new code coexist until traffic proves the replacement.
Phased rollout keeps risk low because each slice ships behind a feature flag with rollback ready. Phase one, audit and dependency upgrades, takes 8 to 16 hours. Phase two, extracting 3 to 5 hot routes into typed services with Vitest and Supertest coverage, takes 20 to 40 hours. Phase three, cutover with pino log parity checks and k6 load tests at 2x peak traffic, takes 10 to 20 hours per batch.
Taking over a struggling Node.js codebase starts with evidence, not rewrites. The client provides repository access, a README or runbook, environment variable samples, recent heap snapshots or APM traces from Datadog or New Relic, and a list of the three most painful incidents. A senior engineer then audits event loop lag with clinic.js, dependency freshness, error handling in Express middleware, and test coverage.
Some codebases cost less to replace than to repair, and naming that early saves budget. Red flags include zero tests with 200k+ lines of callback-heavy JavaScript, pinned Node 12 with native modules that no longer compile, and event listener leaks nobody can trace. In those cases a scoped rewrite of the hot path, 30 to 60 hours, beats months of patching. Everything else usually responds to focused fixes within 10 to 25 hours.
Audit rule: fix versus rewrite
Rewrite only when repair cost exceeds replacement: unmaintained Node versions with broken native builds, no tests across hundreds of thousands of lines, or queue consumers that lose messages. Otherwise assign a 4-hour audit producing a ranked defect list with hour estimates per fix.
Strong Node.js candidates talk in specifics: p50/p99 latency numbers they moved, how they isolated an event loop stall with clinic.js flame graphs, and how they sized BullMQ concurrency against Redis memory. Junior signals include promises chained without catch blocks, synchronous fs calls inside request handlers, and storing sessions in process memory. Ask for a production incident story and listen for metrics, not adjectives.
A paid trial of 3 to 5 hours predicts on-the-job quality better than whiteboard quizzes. Give the candidate a small Fastify service with a slow endpoint, a missing idempotency key, and one flaky Supertest case. Acceptance criteria: p99 latency halved or explained with traces, duplicate POSTs handled safely, tests green in CI, and a short note listing what they would address with 10 more hours.
You will receive candidate profiles with verified commercial Node.js track records within 2 to 4 hours.
Rates range from $45 to $95 per hour, set directly by each verified engineer based on framework specialization in Fastify, Express, or NestJS.
Yes. Senior engineers capture and analyze V8 heap snapshots to identify uncollected closures, listener leaks, and buffer growth.
Yes. Our engineers write clean TypeScript backends utilizing Fastify, NestJS, Express, and Prisma/Drizzle ORMs.
You own 100% of all Git repositories, test suites, and cloud infrastructure keys upon milestone approval.
Pick Fastify for JSON APIs above 10,000 requests per second, NestJS for teams of 6+ engineers needing module boundaries, Express for fastest hiring, and Hono for edge runtimes. A 2-hour architecture review maps your throughput targets to the right pick before any contract.
Most tasks land between 8 and 40 hours: memory-leak audits take 8 to 20 hours, WebSocket services 15 to 30 hours, and microservice builds 15 to 40 hours. You get a fixed hour estimate before work starts, and matching with an engineer takes 2 to 4 hours.
Yes, if the code passes audit: runnable Node 18/20 builds, recoverable dependencies, and traceable error paths. You provide repo access, env samples, and APM traces; a 4-hour audit then returns a ranked fix list. Codebases on Node 12 with broken native modules are usually cheaper to partially rewrite in 30 to 60 hours.
Run a paid 3 to 5 hour trial at the agreed $45-$95/hr rate: fix a slow Fastify endpoint, add idempotency to a POST route, and turn one flaky Supertest case green. Pass bar is halved p99 latency or a trace-backed explanation, safe duplicate handling, and green CI.
Repository access, Node version and deploy target, env variable samples, API specs or Postman collections, and 30 minutes with whoever owns the roadmap. With that bundle an engineer ships the first pull request the same day matching completes, typically within 2 to 4 hours of your request.
Every engagement includes a 2-week defect window: regressions from delivered work are fixed without new billing. After that, most clients keep 5 to 10 hours per month at $45-$95/hr for dependency upgrades, pino log review, and k6 load re-checks.
Yes. Every build ships with Vitest and Supertest suites plus GitHub Actions running lint, type checks, and tests on each pull request, typically 4 to 8 hours of setup. Coverage gates block merges that drop tested paths, so later changes stay safe.
