Full-Stack Developer

Hire a senior full-stack developer

One person who owns the whole thing — database schema, API, frontend, deployment, and the production incident at 2am. No handoffs between a backend contractor and a frontend contractor who blame each other when something breaks.

★★★★★50+ projects delivered · 5.00 rating · 11+ repeat clients
Ustym Kushnir — Full-Stack Developer

The part most people get wrong

Most projects do not fail on code quality. They fail because responsibility is split across people who each did their part correctly and nobody owned the seam between them. A single senior full-stack engineer removes every seam.

What you get

  • →10+ years shipping production software. 50+ projects delivered across direct clients and platforms, 5.00 average rating, 11+ clients who came back.
  • →Next.js 14/15/16 + TypeScript on the front, Node.js or NestJS on the back, PostgreSQL with Prisma underneath.
  • →Deployment included — Docker, Caddy, systemd, Let's Encrypt, zero-downtime redeploys with schema-drift guards.
  • →Playwright E2E suites so a schema change never silently breaks a production flow.
  • →The repository is transferred to your GitHub organization at delivery. You own it outright.
  • →Written daily updates in your timezone. English, Spanish, Portuguese or Polish.
  • →60-day warranty on behavioral defects, free of charge.

Proof — shipped and in production

Frequently asked

What does "full-stack" actually mean in your case?+

Database design, API architecture, frontend implementation, UI design, deployment, monitoring, and the incident response when something breaks. I do not hand off the design to a designer or the deploy to a DevOps contractor. The whole thing is one person's responsibility, which is why nothing falls through a seam.

Do you work on existing codebases or only greenfield?+

Both. Roughly half of my engagements are inheriting someone else's code — finishing an abandoned project, fixing a broken integration, or modernizing something that outgrew its original shape. For legacy work the first deliverable is a written read of what is actually there before a line is changed.

How do you price?+

Honest scope × USD 10/hour, delivered as a written budget in the proposal. The rate does not vary by client or by country. What varies is the scope, and you are always shown which pieces would slide out to hit a specific number.

This role is also called

  • software engineer
  • web developer
  • backend developer
  • frontend developer
  • application developer
  • product engineer

Start with a written brief

Describe what the business is losing today and what the target outcome looks like. I come back with a concrete plan against that document — in English, Spanish, Portuguese or Polish.

Other roles

AI Engineer

Not a prompt consultant. An engineer who puts an LLM inside a process that already runs money through it — with cost routing, grounding, guardrails, escalation to humans, and a test suite that catches regressions before customers do.

Blockchain Developer

Contracts that shipped to mainnet and held real value — not a tutorial fork with the variable names changed. Vetra, a USD-backed stablecoin on Polygon with Chainlink Functions verifying reserves in real time, is the reference.

Security Engineer

When a production server is owned, the clock matters more than the credential. I do the full incident response workflow — evidence-preserving triage, eradication, credential rotation, patching (including hand-written patches when the vendor fix has not shipped), and hardening that makes round two expensive.

Business Automation Engineer

Not a Zapier consultant. An engineer who replaces the spreadsheet, the WhatsApp group and the clipboard with software the team stops having to think about — written in code you own, on infrastructure you control, with no per-execution billing.

Fintech Developer

The money layer, built with the paranoia it deserves. Signed webhooks, idempotent handlers, integer minor units, append-only ledgers, row-level locks. The boring rules that prevent the entire class of "the numbers do not add up" tickets.

WhatsApp API Developer

Official WhatsApp Business Cloud API via a Meta-approved BSP. Not Baileys, not Evolution, not a QR-scanning wrapper that gets the client's number banned in a week. The integration that survives contact with a real business.

Industrial Automation & IoT Engineer

Sensors are cheap now. The expensive part is turning a telemetry firehose into an alert that reaches the right person before the damage is done — and not one alert per reading, which trains everyone to ignore them.

Booking System Developer

The booking engine your business actually runs on — owned outright, not rented per seat. Real-time calendar sync, WhatsApp reminders in your voice, payments into your own account, and a cancellation queue that refills the slot before the front desk even notices.