How to build · 11

Ready-Made Solutions

Code recipes for specific tasks: components, utilities, Next.js, Spring, mobile, auth and SQL.

Read: 0 / 11React Components JavaScript Utilities Next.js Solutions Java / Spring Recipes React Native Recipes Flutter Components Authentication Recipes API Recipes Database Recipes Reusable Architecture Patterns

React Components

Code recipe✓
Recipe: an accessible modal dialog in React
Use the native <dialog> and open it with showModal() from a React effect: the browser puts the dialog in the top layer, makes the page underneath inert, closes it on Escape and returns focus to whatever had it before the dialog opened. The component only has to sync state through the close event, close on a backdrop click, label the dialog with aria-labelledby and lock scrolling with a single CSS rule. Below are a ready-made Modal.tsx, styles that respect prefers-reduced-motion, and tests that run in a real browser.
Intermediate · 8 min read · practice ~40–90 min

JavaScript Utilities

Code recipe✓
Recipe: debounce and throttle
Debounce delays a call until events stop for a given pause — that is search-as-you-type and recalculating after a resize. Throttle lets a call through at most once per interval while events keep coming — that is scroll handling. Below are typed implementations with cancel, flush and leading/trailing options, a useDebouncedValue hook for React, and Vitest tests on fake timers.
Beginner · 6 min read · practice ~20–40 min

Next.js Solutions

Java / Spring Recipes

Code recipe✓
Recipe: a unified error format in Spring Boot
A unified error format in Spring Boot takes one class: a @RestControllerAdvice that extends ResponseEntityExceptionHandler returns an RFC 9457 ProblemDetail for every case — validation errors, 404, 409 and unexpected 500s. The client always gets application/problem+json with a clear detail, while the stack trace stays in the log and is linked to the response through an errorId.
Intermediate · 7 min read · practice ~20–40 min

React Native Recipes

Code recipe✓
Recipe: a list loaded from an API with pull-to-refresh in React Native
In React Native a list from an API is built on FlatList: the refreshing + onRefresh pair adds the pull-to-refresh gesture, and onEndReached loads the next page. To survive a real network you also need separate loading, error and empty states, a synchronous flag against duplicate load-more calls, cancellation of stale requests with AbortController, and de-duplication by id. Below is a ready hook and screen for Expo SDK 57 with nine tests.
Intermediate · 7 min read · practice ~20–40 min

Flutter Components

Code recipe✓
Recipe: a form with validation in Flutter
In Flutter a form is a Form widget with a GlobalKey<FormState> and TextFormField fields with a validator function that returns an error text or null. To keep errors from appearing while the user types, give the form AutovalidateMode.onUnfocus and the fields onUserInteractionIfError. Below is a ready lead form for Flutter 3.47 with a phone mask, a sending state, server errors, screen reader labels and 11 tests.
Intermediate · 7 min read · practice ~20–40 min

Authentication Recipes

Code recipe✓
Recipe: storing passwords — hashing and verification
Passwords are stored neither in plain text nor as SHA-256, but as a slow hash with a unique salt: OWASP recommends Argon2id with at least 19 MiB of memory, two passes and one lane. This recipe gives you a ready-made Node.js 24 module — hashing, verification, rehashing when the parameters change, migration from old bcrypt hashes on login, and a check for an unknown email that takes as long as for a real one.
Intermediate · 9 min read · practice ~20–40 min

API Recipes

Code recipe✓
Recipe: a typed API client on fetch
A typed API client is a thin wrapper over fetch that every request in the project goes through: it builds the URL from the base address, sets shared headers, limits the waiting time, checks the response with a Zod schema and turns any failure into a single ApiError class with parsed Problem Details. This recipe gives you a ready-made api-client.ts file of about 180 lines, an example API module and tests against a local HTTP server.
Intermediate · 7 min read · practice ~20–40 min

Database Recipes

Code recipe✓
Recipe: keyset pagination in SQL
Keyset pagination (the seek method) selects the next page with "everything after the last row shown": WHERE (created_at, id) < ($1, $2) ORDER BY created_at DESC, id DESC LIMIT 21. With a composite index on (created_at, id) the database reads only the rows of the page, so speed does not depend on depth, and new records do not shift the pages. The trade-off: you cannot jump straight to page N — the client gets a cursor and pages from it.
Intermediate · 8 min read · practice ~20–40 min

Reusable Architecture Patterns

Code recipe✓
Recipe: a port and an adapter for an external service
A port is an interface in which the application describes what it needs from an external service in its own words: «send an SMS», not «POST /v2/messages». An adapter implements the port for a specific provider and translates formats and errors both ways; a fake adapter implements the same port in memory for tests. One contract test runs against both adapters and guarantees that the fake behaves like the real adapter.
Advanced · 7 min read · practice ~40–90 min

Learning paths with this direction

JavaScript from scratch · 9 →React · 8 →Next.js · 7 →Java · 6 →Spring Boot · 7 →Backend with Node.js · 8 →React Native + Expo · 9 →Flutter + Dart · 6 →SQL and PostgreSQL · 9 →Software architecture · 9 →APIs and integrations · 8 →← All directions

Tell us about your task — we'll review your request and get back to you

Got a project?
We'll scope and estimate it — for free.

Tell us about the product or the problem. After reviewing the task we'll come back with an architecture, a timeline and a price for the first version.

Scope and risks estimated before we start
NDA — yours or ours
Work starts within a week

Message on WhatsApp