Available for B2B contracts · 20h/week · remote from Katowice, Poland
B2B / FreelanceI build and scale Django backends, integrations, and automation for B2B products that have to run reliably in production.
Typical work: Django REST APIs, PostgreSQL performance, Stripe and LLM/RAG integrations, and background jobs that remove manual work. I also run AiVisible.pl, an AI visibility (GEO/AEO) agency for B2B companies.
About Me
I'm Rafal Fuchs, a Senior Backend Engineer based in Katowice, Poland, with 5+ years of hands-on experience building, scaling, and maintaining production web applications in Python and Django. My core stack is Django, Django REST Framework, PostgreSQL, Celery, Redis, Docker, and AWS/GCP.
Since 2022 I have worked on the backend of Useme, a Polish freelance marketplace (Job Board search refactor, the Useme Plus membership product). I also run AiVisible.pl, an AI visibility agency that helps B2B companies get recommended by ChatGPT, Gemini, Claude, and Perplexity. I work remotely on B2B contracts and freelance projects and issue VAT invoices.
Services
I design new Django/DRF systems or fix existing ones: data model, API design, PostgreSQL indexes and queries, caching, background jobs. Typical outcome: lower API latency and a codebase your team can keep extending.
See the case study: Useme - Job Board search refactorBefore I propose a stack or a refactor, I ask what it changes for revenue, time-to-market, or operating cost. You get trade-offs explained in business terms and a scope you can approve or cut.
Celery workers, schedulers, and crawlers (including Playwright for protected pages) that collect data, update systems, and send alerts. Example: a KAS listing monitor scanning sources every 2.5 s with e-mail and Discord alerts.
See the case study: KAS listing monitor - near real-time scraping and alertsStripe subscription lifecycle (checkout, webhooks, access control), OpenAI and Anthropic APIs, retrieval with pgvector, KYC flows, CRM and partner APIs. Example: ParentApp, an AI SaaS with Stripe billing live from day one.
See the case study: ParentApp - AI assistant for parents (SaaS)Authentication (JWT/OAuth), permission models, action logs, and data handling that pass technical due diligence. Useful before fundraising, an audit, or selling to enterprise customers.
Case studies
Each case study covers the business problem, the delivery scope, and the outcome. Where a client can be named, it is; anonymised projects describe the mechanism and the result.
AiVisible.pl is the AI visibility agency I founded and run: it audits, improves, and monitors how B2B brands appear in answers from ChatGPT, Gemini, Claude, and Perplexity.
Business value: A B2B company gets a clear answer whether AI assistants recommend it, who wins the competitive shortlist, and which changes improve visibility beyond classic SEO.
An AI assistant for parents taken from MVP to a live subscription SaaS: Django/DRF backend, Stripe billing, and OpenAI-powered conversations.
Business value: A monetizable digital service launched quickly: subscriptions worked from day one and the architecture allowed adding AI and content features without rework.
Backend for Useme Plus, a membership product that lets freelancers settle work without registering a business: cost calculator, Autenti e-signatures, and automated membership validation.
Business value: A new revenue line for the platform, faster member onboarding, and a customer-service team relieved of manual validation.
Rebuilt job and freelancer search on Useme, a marketplace with thousands of active jobs a month: full filtering, an SEO tag system, a denormalized read model, rolled out under feature flags.
Business value: Simpler search for users, faster page loads through a denormalized read model, more Google visibility from a larger SEO tag base, and rollouts with no service interruption.
A daemon that scans KAS and tax-office listing pages every 2.5 seconds, detects new sale offers, prepares the e-mail application from the listing data, and reports every step to Discord.
Business value: In this process seconds decide: whoever detects a listing first can file the purchase request first. The team learns about a new listing within seconds instead of checking pages by hand.
A data pipeline for a services company that collects, normalizes, validates, and schedules outbound lead data so campaigns start without manual clean-up.
Business value: More qualified leads at lower operational cost and with higher data quality.
A Django automation suite connecting partner and internal APIs with asynchronous orchestration and SLA reporting, for an organization whose critical workflows ran across disconnected tools.
Business value: Shorter process cycle time and fewer manual errors in business-critical workflows.
Available now
I currently have 20 hours a week for B2B contracts: Django backend work, LLM/RAG integrations, technical consulting, and GEO / AI visibility audits (the audits mainly for Polish B2B companies, through AiVisible.pl).
I reply within 24h on business days with next steps or a scope proposal. Prefer e-mail? contact@rafalfuchs.dev
How I work
You send a short brief. Within 24h on business days I reply with questions or a proposed next step, usually a call to clarify goals, constraints, and the current state of the system.
You get a written scope, timeline, and price (fixed scope or hourly/sprint) before any work starts. For existing systems this begins with a code and architecture review.
Small, reviewable increments with tests, code review, and CI/CD. Larger changes go out under feature flags so they can be rolled back. You see progress regularly, not at the end.
Monitoring, performance tuning, and documentation after go-live. Support terms are agreed per project.
Core Skills
Python
Django
Django REST Framework (DRF)
GraphQL
Celery
Redis
API integrations
Authentication (JWT / OAuth)
Background jobs
System design
Performance optimization
Scalable backend services
PostgreSQL
MySQL
SQLite
MongoDB
SQL query optimization
Caching strategies
Git
Docker
Linux
CI/CD
Environment configuration
Nginx
AWS
GCP
Ansible
Kubernetes
Terraform
Grafana
React
JavaScript
TypeScript
HTML5
CSS
SASS
Need a senior Django backend engineer on a B2B contract?
Describe your projectClient feedback
Clear communication and fast support across two automation projects. Understood the business context and delivered a solution that has been running flawlessly for months.
Great communication, clear technical explanations, and fast delivery. Doesn't just code - actively suggests better approaches and keeps quality high.
The service description actually matched the delivered work, which doesn't happen often. A competent person in the right place who shares knowledge and guidance. Satisfaction that leads to coming back for the next project!
Professional approach, strong PostgreSQL and Django skills. Delivered optimizations that cut API response time by over 60%.
We hired for SaaS backend architecture and implementation. Delivered a modular system with Stripe payments that worked on production from day one.
Automated a critical operations process that used to take the team several hours daily. Now it runs in the background with full dashboard visibility.
FAQ
I'm a senior Python/Django backend engineer. I build and scale Django REST APIs, PostgreSQL-backed systems, integrations (Stripe, OpenAI, Anthropic, partner APIs), and automation for B2B products: startups launching a SaaS, product companies and marketplaces improving an existing system, and agencies that need senior backend capacity. I also run AiVisible.pl, an AI visibility agency for B2B companies.
B2B contracts start at 150 PLN/h net (+VAT). Well-defined projects can be quoted as a fixed scope. Smaller integrations and optimizations usually take 1-2 weeks; a new backend module typically 4-8 weeks. You get a written estimate before any work starts.
Currently 20 hours a week for B2B contracts, fully remote, with Katowice, Poland as my base. I respond to new inquiries within 24 hours on business days.
Send a short brief through the form or by e-mail. I reply within 24 hours with questions or a proposed call. After the call you receive a written scope, timeline, and price, and work starts only after you approve it. For existing systems the first step is a code and architecture review.
Work is delivered in small, reviewable increments with tests, code review, and CI/CD. Larger changes go out behind feature flags so they can be rolled back. In the hourly or sprint model you can pause or stop after any sprint; with a fixed scope, the scope is agreed in writing first.
Yes. OpenAI and Anthropic APIs, embeddings and pgvector-based retrieval, conversation memory and context handling in production. Example: ParentApp, an AI assistant with OpenAI integration and Stripe billing.
Yes. I review the current stack, find bottlenecks (usually PostgreSQL queries, missing indexes, N+1 in the ORM, no caching), and implement fixes for speed, stability, and scalability. A client-reported outcome from one such project: API response time cut by over 60%.
Hourly or sprint-based for open-ended work, fixed scope for well-defined projects. I work on B2B contracts and issue VAT invoices. I sign NDAs. Terms are agreed in writing before work starts.
Yes. I regularly take over existing codebases. I start with a code and architecture audit to understand the current state, identify technical debt, and plan a safe path forward, then deliver changes in small, reversible steps.
Yes. I work fully remote and regularly collaborate with product teams, DevOps, and other developers in the client's repository and tooling. I use Git, code reviews, Slack, and daily standups.
Yes. Post-deployment support covers monitoring, quick fixes, and optimization. Terms are set individually for each project.
Yes. I work with Polish and international clients fully remotely, in Polish and English, and adapt to different time zones.
Yes. Standalone code review sessions and architecture consulting engagements. They are useful before scaling a product, hiring a team, or preparing for a technical audit or due diligence.
Marketplace platforms (Useme), SaaS products (ParentApp), fintech and KYC integrations, automation pipelines, and AI-powered applications. I adapt quickly to domain-specific requirements.
Yes. I sign NDAs and work under standard B2B contract agreements. Confidentiality is a default part of my professional practice.
Yes. Automated tests are part of my standard development process, together with code review and CI/CD, to keep releases reliable.
Contact
Describe the product, the current problem, and the outcome you expect. Add a deadline or budget range if you have one.