Senior full-stack for your team.
I join your team for a short project or for the long run. Over 10 years in JavaScript and TypeScript: front-end, back-end, mobile and AI. Remote, as a contractor.
We agree the start date after a call
Who it’s for
When I can
help your team.
- A deadline is closeYou need someone who gets into the project fast and delivers a specific part of it.
- No senior on the teamYour team needs someone to make architecture calls, review code and help the juniors.
- You want to add AIAssistants, RAG, automations: someone who has already shipped them in products.
- A long project, steady helpI join the team for months, at your team’s pace.
Stack
What I’m
strong at.
JavaScript and TypeScript are the base. Day to day:
Front-end
React, Next.js, Angular, Vue and Nuxt; RxJS, Redux, NgRx, design systems, responsive and RTL layouts.
Back-end
Node.js, NestJS, Fastify, REST, Swagger, JWT, Strapi.
Mobile
React Native and Expo, Firebase and Crashlytics.
AI
OpenAI, LangChain, RAG, n8n and Make. I write code together with AI agents (Claude Code, Cursor).
Quality
Tests (Jest), ESLint, SonarQube, code review and CI/CD.
Infrastructure
Docker, Vercel, AWS, Azure.
Teamwork
Sprints, code reviews, mentoring and presentations for the team.
Communication
English and Polish. I work with clients all over the world, from Poland (CET).
How we start
First PR
within a week.
A quick start on the project, then work at your team’s pace.
Start with a call-
Day 0
A 30-minute call
You tell me about the project, the team and the stack. We agree the scope and my availability.
-
Week 1
Getting into the project
Access, a read through the code and the docs, the first task.
-
Week 1
First PR
The first change passes review and goes into the project.
-
Every sprint
Steady delivery
Sprints, reviews and team meetings, the way you already work.
-
At the end
Handover
The docs and the knowledge stay with the team.
We worked on the same project for almost two years, and I know one thing — his code barely needs a tester. Committed, focused and one of the best frontend developers I’ve worked with in seven years of QA.
Why me
A senior
who delivers.
- Over 10 years of experienceSince 2014 I have built products for clients all over the world: fintech, e-commerce, SaaS.
- Code qualityReadable, tested code that the team can keep building on after me.
- Remote without frictionSlack, e-mail and video calls. From Poland it is easy to fit in with Europe, and the US East Coast shares my afternoons.
Questions
Before
you ask.
Not seeing your question? Write to me or book a short call. I reply within 24 hours.
Book a 30-min callHow do you work with clients?
As a contractor (B2B), remotely. We agree the scope and my availability together: from a short project to a long collaboration.
When can you start?
We agree the start date after a call, depending on the project and how much of my time you need.
Do you join agencies and software houses?
Yes, I join product teams as well as teams that build projects for their own clients.
What hours do you work?
I work from Poland (CET). It is easy to fit in with teams in Europe and the UK, and we share working hours with the US East Coast in the afternoon.
Can I see your CV?
Yes, the interactive CV with projects and the stack is at sebastianmusial.pl/en/cv, with a PDF to download.
Last updated:
Contact
Let’s talk.
Write a few sentences about what you want to build. I reply within 24 hours.
- You write a few lines
- I reply within 24 h
- We talk for 30 min