Engineering teams for AI products

We build the web and mobile software behind them. And own how it runs!

products shipped since 202335

specialists in-house30

countries8

of clients come back80%

About Us

Software Company

Based in Warsaw and working the way the name suggests: you own the product, we're the engineering behind it. Meet the team and see how we work on the about page.

Why Sidekick

Our partners choose us for

Fintech, DeFi and AI expertise

Payment flows, DeFi protocols, AI agents. We have built these systems since 2023, and your project starts on patterns proven in production.

Engineers who own delivery

Each engineer runs their scope end to end: estimates, code, releases, fixes. You introduce the product once; first commits land within days. From you the project needs priorities and one slot a week for the demo.

Stable architecture, modern tools

We build on foundations with decades of production behind them and add modern tools where they pay off: LLM pipelines, agent frameworks, managed infrastructure. Every line that ships has an engineer responsible for it.

Clear communication

Our engineers work in your channels and your calls, whatever your team runs on, and answer on the spot. Weekly demos, decisions in writing, and no layers between you and the person writing your code.

No surprises after kickoff

You interview each engineer before the start, and that engineer ships the product. We staff from our own thirty specialists under EU contracts, and the terms agreed on day one hold to release.

Global Presence

North America and Europe

Our clients run standups in New York, sprint planning in London, brainstorms that start late in Vienna. Sidekick engineers are in those meetings, camera on, working the same hours as the team. Demos land every week, decisions end up in writing, and the team's rituals stay as the team runs them. Eight countries on our client map, one name in your contract.

Services

Elevating Teams with Expertise

Web Development

We build web applications end to end: front end, back end, infrastructure. React and Next.js on the client, Node.js on the server, PostgreSQL and AWS underneath. Before writing code we agree on what the application must do for your business, then deliver in weekly increments you can test yourself. The result loads fast, survives real traffic, and stays easy to extend a year later.

Mobile Development

We ship iOS and Android apps, native or cross-platform with React Native. The choice depends on your audience, budget and release plans; we lay out the trade-offs before you commit to either path. You get an app that passes store review, works offline where it should, and shares logic with your web product instead of duplicating it.

UI/UX Design

Design starts with user flows: what a person needs to do in your product and how many steps it takes. We prototype, test with real users, and polish visuals last. Interfaces come out clear enough that onboarding gets shorter and support tickets drop.

Technologies

Our technology stack

Node.JSBackend

HTML5Frontend

React-NativeMobile

AndroidMobile

SwiftMobile

KotlinMobile

ReactFrontend

MistralDL/ML

SupabaseInfrastructure

OpenAIDL/ML

ElectronDesktop

ClaudeDL/ML

AWSInfrastructure

PostgreSQLDatabase

RedisDatabase

TensorFlowDL/ML

KerasDL/ML

JavaBackend

SpringBackend

FlutterMobile

VueFrontend

AngularFrontend

SnowflakeData & Analytics

RedshiftData & Analytics

TableauData & Analytics

MetabaseData & Analytics

TruffleBlockchain Development

Microsoft AzureInfrastructure

SolidityBlockchain Development

Hyperledger FabricBlockchain Development

HardhatBlockchain Development

GanacheBlockchain Development

CardanoBlockchain Platform

SolanaBlockchain Platform

Binance Smart Chain (BSC)Blockchain Platform

EthereumBlockchain Platform

Engagement Models

How we work together

Fixed Price

For small and medium projects with a defined scope. We agree on deliverables, deadline and budget before the start, and those numbers hold. Choose it when predictability matters more than flexibility; if requirements are still moving, one of the models below fits better.

Time and Materials (T&M)

You pay for actual hours at an agreed rate. Scope can change any week: add features, reorder priorities, pause a track. We report hours and progress weekly, so the budget stays visible sprint by sprint. Fits products that evolve as you learn from users.

Dedicated Team

A team assigned to your product only, for months or years. Engineers keep context, velocity grows over time, and you plan capacity like your own department. This is the model most of our long-term clients use.

Hybrid Engagement

Fixed price for the defined core, hourly work for what emerges along the way. You get a firm budget where the scope is clear and room to adjust where it isn't. A practical default for a first project with us.

Get in touch

Start with a 15-minute call

Pick a slot that works for you. Anything you add about the topic helps us put the right call together.

AngelinaBusiness Development Manager