sisl.pl
sisl.pl — est. 2021
sisl.pl — est. 2021

SISL.PL — boutique web studio in Poland: custom websites, online stores and technical SEO

// independent // studio // web //

Websites, online stores and Magento care at fixed prices. You see the price before any work starts.

no VAT added · we reply within one business day

// FOR INTERNATIONAL CLIENTS

Why hire a Polish boutique dev studio for your project?

  • → Same time zone as Western Europe. Warsaw is GMT+1/+2 — overlaps every working hour with Berlin, Amsterdam, Paris, London. No 3 AM Slack pings, no async-only workflows.
  • → EU-native (GDPR, ePrivacy, DSA). We've built and shipped under the same regulatory framework as your German/French/Dutch business. No "we'll figure it out" stage on cookie consent, data residency, lawful basis.
  • → Western-grade engineering at a Polish rate. Senior dev day-rate sits at 35–45% of equivalent Berlin/Amsterdam rates without sacrificing English fluency, code review discipline, or test coverage.
  • → Boutique, not body-shop. Every project goes through one senior who owns the full stack — not a 5-person "team" where the lead is on three other projects. You always talk to the person who writes the code.
  • → Modern stack, no fragile WordPress glue. FastAPI, Next.js, Astro, Magento for e-commerce, Postgres + Redis, Docker-first deploys. Same toolbox we use for our own products (live: sisl.pl/battlemap) — proven on real production traffic, not just demo decks.

Invoicing in EUR or USD on request. NDA + IP assignment template available. Standard contract: monthly retainer or fixed scope; 50/50 milestone split for projects above EUR 5,000.

7
working days to a finished business website
5
years of experience
<24h
response time

What we do best

Each tile leads to a page with the scope and the price. Prices match the pricing page; no VAT is added.

web

Websites

A company website of up to 8 pages costs 1,490 PLN and ships in 7 working days. We build it on WordPress without page builders, so you can edit the text yourself, and the mobile Lighthouse score (90 or higher) goes into the contract.

1,490 PLN ≈ €340 · custom design from 4,900 PLN ≈ €1,120

stores

Online stores

WooCommerce stores start at 3,800 PLN for up to 100 products. Once you have thousands of products, B2B price lists or an ERP to connect, we build on Magento 2 with Hyvä, from 19,500 PLN.

WooCommerce ≈ €870 · Magento ≈ €4,470

seo

SEO

Technical SEO, content and links you earn. The first audit is free and arrives within 24 hours; retainers from $400 a month.

support

Maintenance

Hosting, daily backups, uptime monitoring and updates for WordPress and WooCommerce from 599 PLN a month. One-off fixes without a plan cost 220 PLN an hour, billed in 15-minute blocks.

599 PLN/mo ≈ €135/mo · 220 PLN/h ≈ €50/h

From idea to launch

Transparent process, regular communication, zero surprises.

01

Discovery

We talk about business, goals, and target audience. We define the scope.

02

Design

Wireframes and prototypes. We iterate until it’s just right.

03

Build

Clean code, tests, code review. We show progress regularly.

04

Launch

Deployment, monitoring, training. Then ongoing care and growth.

Selected work

Every project is a different story. What they share — clients who come back.

Klupś IT Solutions — computer repair shop
Business site

Klupś IT Solutions — computer repair shop

New site for a local computer repair shop in Tarnowo Podgórne, built from scratch: three divisions (repairs, custom PC builds, websites), a ticket panel with ZK numbers and repair status for customers, and a blog with an editor. FastAPI + SQLite, technical SEO (sitemap with real lastmod, JSON-LD from a single price file, IndexNow), consent banner and a design drawn from the logo: emerald crystals and PCB traces.

POLMAR — firewood
Business site

POLMAR — firewood

Site for a firewood seller: pricing, phone orders, delivery range and trust sections (13 years, honest volume). Built for fast contact and conversion.

Co mam zjeść? — food map
Web app

Co mam zjeść? — food map

Interactive map and ranking of eateries reviewed by YouTubers — 1048 spots, filters by cuisine, city and rating, plus 'near me' search. Built with SISL.

SISL Battle Map: Real-Time Conflict Data Platform
Web Application / Data Platform

SISL Battle Map: Real-Time Conflict Data Platform

Real-time interactive conflict map aggregating 270+ daily events from 10 regions. Features custom 4-language translation engine, historical backfill, and a performant freemium API for OSINT analysts, journalists, and fintechs. Built with FastAPI & PWA.

mockql
Web app

mockql

MockQL is a hosted GraphQL mock server that turns any SDL schema into a live endpoint in one click — no backend setup, no resolver boilerplate, no fixtures. An AST-driven engine infers behavior for every type (scalars, objects, lists, enums, unions, interfaces, recursive references) directly from the schema, with deterministic fake data from @faker-js/faker

PgX-Ray - Postgres EXPLAIN Visualiser
Web app

PgX-Ray - Postgres EXPLAIN Visualiser

A client-side visualiser for Postgres EXPLAIN (ANALYZE, FORMAT JSON) plans — paste the JSON, get an interactive graph with heatmap-coloured hotspots and automatic "Smart Insights" that flag sequential scans, row-estimate drift, Nested Loop explosions and work_mem spills. Runs entirely in the browser — no data leaves the tab. Next.js 14 (static export), React Flow, strict TypeScript, Zustand, Tailwind; EN/PL with locale-aware number formatting; 120 tests across parser, rule engine, XSS surface, determinism and dictionary parity.

Hookzy
Web app

Hookzy

Check if your webhook works

Check your store.
Free.

Enter an address and in ~30 seconds see what your Magento 2 exposes publicly: files that should not be reachable, security headers, technical SEO and performance measured on real users (Chrome UX Report). No login, nothing to install in the store — only what every visitor can already see.

Run a free scan

Pricing — on the table.

No VAT is added to our prices, fixed-price for defined scope. Final quote in 24h after brief. Subscription for small biz, fixed projects for everything else.

// company site

Company site

from 1 490 zł ≈ €340

Up to 8 pages on WordPress without page builders, live in 7 working days. Mobile speed and copyright transfer written into the contract. Custom design from 4 900 zł (≈ €1,120).

  • Lighthouse mobile ≥ 90 in the contract
  • Full copyright transfer, admin access
  • Hosting of your choice, no site subscription
7 working days
// landing page

Landing page

from 990 zł ≈ €230

Single high-converting page for Google/Meta Ads. A/B-ready, Pixel + GA4 wired.

  • Mobile-first hero + CTA
  • Conversion tracking setup
  • LCP < 2.5s guaranteed
5-10 days
// custom design

Custom-designed site

from 4 900 zł ≈ €1,120

Up to 8 pages designed from scratch, copywriting included, SEO + Schema.org. Larger sites (15-30 pages, multilang) quoted after a brief.

  • Custom Figma design + WordPress / headless CMS
  • Mailchimp / HubSpot / Calendly hooks
  • PL + EN versions, hreflang, schema.org
2-3 weeks
// woocommerce

WooCommerce store

from 3 800 zł ≈ €870

Up to 100 SKUs, WordPress + Kadence, payment gateway, PL/EN. Store with Allegro, InPost and invoicing, up to 500 products — 4 490 zł (≈ €1,030).

  • Przelewy24 / PayU / BLIK / Stripe
  • Custom theme or fork of starter
  • Voucher system + email automation
2-4 weeks
// magento / adobe commerce 2

Magento / Adobe Commerce 2

from 19 500 zł ≈ €4,470

Entry build from PLN 19,500. With 1k+ SKUs, multistore, B2B customer-specific pricing and ERP integration the budget grows to PLN 59,500+ (3-4 months).

2-4 months
// custom web app

Custom web app / SaaS MVP

individual quote

React/Next.js + FastAPI/Node, auth, admin panel, Stripe Billing, Postgres, Docker deploy.

  • Multi-tenancy + role-based access
  • Stripe Subscriptions + invoicing
  • Sentry monitoring + CI/CD pipeline
6-12 weeks
// after delivery
Maintenance from 599 zł/mo ≈ €135/mo
CARE / GROWTH / PARTNER for WordPress and WooCommerce — uptime, backups, updates, security
// SEO
SEO retainer from 1 500 zł/mo ≈ €345/mo
// full price guide
Pricing 2026 article

Need something not on the list? Just ask — quote in 24h.

Got an idea?

No matter the stage — a sketch on a napkin or a full specification.

get in touch

Let’s build together

Every collaboration starts with a conversation. Zero obligations.

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Tell us about
your project

Fill out the form or write directly. We respond within 24 hours — usually faster.

lokalizacja Polska / zdalnie
odpowiedź < 24h
enter ↵