feniu.pl
Łukasz Lewandowski — engineer & full-stack maker
I build practical applications for people who need to ship a concrete process: MVPs, SaaS products, panels, integrations and automations. I take work from the first problem conversation to production.
- lean MVPs and SaaS products
- automations, bots and integrations
- self-hosting, Docker, Coolify
// now building
build log — what I'm working on right now
- wipBudgetPro — my own budgeting SaaS, monorepo Nuxt + Fastify + Postgres/Redis/MinIO, self-hosted on Coolify
- wipSEO/LLM tooling — language-model-powered tools for content analysis and generation
- liveKSeF — Polish e-invoicing: PDF generation and backend
- liveDiscord bots (community) — family-feud, quizzes, teamquiz, games and a bit of nonsense
- donefeniu.pl — this site: Nuxt 3 + i18n, static build, Caddy/Coolify deploy
// projects
a curated selection — client projects are anonymized
BudgetPro
wipA personal budgeting SaaS built from scratch. Monorepo pairing a Nuxt frontend with a Fastify backend, Postgres for data, Redis for caching and MinIO for file storage, all self-hosted on Coolify.
- scope
- Financial data model, API, dashboard, files, cache and self-hosting.
- outcome
- A SaaS foundation that does not depend on an external PaaS.
Discord community bots
liveA family of homegrown entertainment bots for communities: family-feud games, quizzes, team quizzes, a search bot, facemash and a quirky 'uncle talk' generator. Real-time interactive mechanics that keep a server engaged.
- scope
- Discord commands, realtime games, session state, rankings and game-flow moderation.
- outcome
- Several community-used bots, from simple quizzes to team-based games.
CS2 bots and server integrations
doneBots wiring Discord into Counter-Strike 2 gameplay and game servers (cs2-bot, discord-cs-game). They bridge player stats, server state and in-game mechanics with community channels.
- scope
- Wiring Discord, RCON, server status and player data into one flow.
- outcome
- The community can see game and server state without leaving Discord.
Multi-locale e-commerce for a fashion brand
liveOnline stores in PL/IT/ES editions for a fashion label. A shared SSR storefront with per-market localization of content, catalog and checkout, kept maintainable on a single core.
- scope
- Shared storefront, market localization, catalog, checkout and one maintainable codebase.
- outcome
- Multiple market editions run on one core without duplicating maintenance logic.
client projectprivate projectServer-rendered storefront
doneA client storefront delivered on an SSR architecture: fast first paint, SEO-friendly product pages and integration with a catalog-and-orders backend.
- scope
- Server rendering, product pages, catalog and order-system integration.
- outcome
- Product URLs are fast, indexable and ready for organic traffic.
client projectprivate projectCRM and microservices for a client
liveA microservice-based CRM: a dedicated API, a data-feeding crawler and an operations panel. Decoupled services make each domain easier to scale and maintain.
- scope
- Domain API, data crawler, operations panel, background jobs and containerization.
- outcome
- Client operations are split into services that can evolve and scale separately.
client projectprivate projectClient backoffice
doneA back-office panel supporting a client's internal operations: data management, roles and permissions, and integrations with the company's existing systems.
- scope
- Admin panel, roles, permissions, data forms and integrations with company systems.
- outcome
- Less manual operations work and one panel for repeatable team tasks.
client projectprivate projectLLM-powered SEO tooling
wipA homegrown toolkit that puts language models to work on SEO: content generation and optimization, keyword analysis and automation of repetitive editorial work.
- scope
- Prompts, content-generation flows, keyword analysis and storing results in a database.
- outcome
- Repeatable editorial work moves from a manual process into tooling.
SSR shop with SEO layer for a sports brand
liveAn SSR-based store with a dedicated SEO layer for a sports-equipment brand. Content and structure tuned for organic search visibility.
- scope
- Page structure, SSR rendering, category content and technical indexation foundations.
- outcome
- The storefront is prepared for organic visibility, not only for checkout.
client projectprivate projectKSeF e-invoicing tools
wipTooling for Poland's KSeF e-invoicing system: a backend that talks to the official API, PDF document generation and validation of invoice XML structures.
- scope
- API integration, XML structures, PDF generation, validation and document storage.
- outcome
- The e-invoicing core is separated from manual document generation.
Automations, crawlers and webhooks
liveA set of automations: crawlers and scrapers that harvest data, a podcast feed generator, and webhooks that stitch external services into finished workflows.
- scope
- Crawlers, scrapers, webhooks, scheduled jobs and lightweight control panels.
- outcome
- Data collection and repeatable tasks move into automated flows.
Desktop fitness app
doneA desktop fitness app built with Electron: workout planning and progress tracking in a native window backed by local data storage.
- scope
- Desktop app, local data, workout views and progress tracking.
- outcome
- The training plan works offline and does not require an external backend.
Programmatic video generation (Remotion)
doneCode-driven video built with Remotion: data-fed dynamic scenes rendered automatically instead of hand-edited in a video editor.
- scope
- Remotion compositions, input data, scene templates and automatic rendering.
- outcome
- Videos can be generated repeatedly from data instead of edited by hand.
MVP scaffolds and backend boilerplates
archivedPersonal starter kits for spinning up projects fast (mvp-backend, smartmvp): a ready backend structure, auth and configuration that shortcut the build of new SaaS products.
- scope
- Backend structure, auth, environment config, Docker and reusable modules.
- outcome
- New MVPs start from a prepared foundation instead of an empty repo.
// work with me
I fit best into small and mid-sized projects where someone needs to understand the domain quickly, design a sane flow and ship a working system. I do not sell slide decks — I ship apps, integrations and automations that keep working after deployment.
- MVP / SaaSFrom process sketch to frontend, API, database, auth and deployment.
- AutomationCrawlers, webhooks, bots, operations panels and tools that reduce manual work.
- Shipping and cleanupStabilizing existing apps, integrations and refactors aimed at real maintenance.
// stack
tools I reach for every day
Languages
- TypeScript
- JavaScript
- PHP
- SQL
- Bash
Frameworks
- Nuxt 3
- Vue 3
- Fastify
- Node.js
- Electron
- Remotion
Data & infra
- PostgreSQL
- Redis
- MinIO
- Docker
- Coolify
- Caddy
AI & automation
- LLM / GPT tooling
- SEO automation
- Scrapers & crawlers
- Webhooks
- KSeF e-invoicing