Full-Stack Developer (React, .Net)

Software Mind; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Benefits offered by this job

Flexible cooperation

International projects

Travel opportunities

Private healthcare

Life insurance

Language courses

Knowledge sharing

Job summary

Software Mind is hiring a frontend engineer to build next-generation risk analysis interfaces. You’ll craft production-grade React/TypeScript features for risk analytics, while integrating with .NET backends and platform APIs.

Expect fast UIs for large datasets, AI-assisted coding, and thorough testing in a PCI-conscious environment. The role involves collaboration with client teams on international projects, with flexible remote cooperation options.

Qualifications

• 3–5 years of commercial software development, incl. 3 years React/TypeScript.
• Experience with data-heavy UIs: tables, grids and charts over large datasets.
• Proficient in C#/.NET: ASP.NET Core Web API, EF Core or Dapper, SQL knowledge.
• REST API integration with typed clients and server-state libraries.
• Daily use of agentic AI coding tools and strong testing discipline.

Responsibilities

• Build and ship production React/TypeScript features for risk analyst interfaces.
• Extend C#/.NET endpoints behind frontend features within API contracts.
• Integrate frontend with platform APIs, handle loading, errors and pagination.
• Keep large datasets fast with virtualization and efficient data fetching.
• Write and review unit, integration and end-to-end tests; ensure AI-generated code quality.
• Respect PCI boundaries: masked/tokenized card data and secure sessions.

Skills

Frontend development

React

TypeScript

Data-heavy UI

CI/CD practices

Tools

TanStack Table

AG Grid

Recharts

ECharts

ASP.NET Core Web API

EF Core

Dapper

SQL

TanStack Query

Jest

Vitest

React Testing Library

Playwright

Cypress

xUnit

NUnit

Docker

Docker Compose

Git

Azure DevOps

GitHub Actions

Job description

• Full-time

Company Description

Software Mind develops solutions that make an impact for companies around the globe. Tech giants & unicorns, transformative projects, emerging technologies and limitless opportunities – these are a few words that describe an average day for us. Building cross-functional engineering teams that take ownership and crave more means we’re always on the lookout for talented people who bring passion and creativity to every project. Our culture embraces openness, acts with respect, shows grit & guts and combines cooperation with enjoyment.

Job Description

Project – the aim you’ll have

Join a next-generation risk analysis and scoring platform built for a payments technology company. The platform combines the client’s own risk rules with AI-driven, pre-scored risk feeds from a global card network. You’ll build the analyst-facing interfaces where risk teams review transactions and merchants and work their alert queues, in a small AI-first delivery team alongside a backend-leaning senior developer.

Role – how you’ll contribute

• Build and ship production React and TypeScript features for risk analyst interfaces: transaction and merchant risk views, score explanations, alert queues, data-heavy tables, filters and charts
• Extend the C#/.NET endpoints behind your features (new fields, filters, endpoints) within API contracts owned by the senior developer
• Integrate the front end with platform APIs, handling loading, error, pagination and caching states cleanly
• Keep large-dataset UIs fast through virtualized tables, smart data fetching, memoization and regular profiling
• Use Claude Code or an equivalent agentic coding tool as your primary accelerator while owning the quality of every line merged
• Write unit, component, integration and end-to-end tests, and review and harden AI-generated code before it reaches production
• Respect the PCI boundary across the stack: masked and tokenized card data only, secure session and token handling
• Work closely with the client’s internal team: stand‑ups, documented design decisions, clean handoffs, CI/CD and repo conventions

Qualifications

Expectations – the experience you need

• 3–5 years of commercial software development, including at least 3 years of production React and TypeScript (hooks, state management, Vite or Next.js)
• Experience building data-heavy UIs: tables, grids and charts over large datasets (e.g. TanStack Table, AG Grid, Recharts, ECharts)
• Working proficiency in C#/.NET: ASP.NET Core Web API, EF Core or Dapper, and enough SQL to change endpoints safely
• REST API integration with typed clients and server-state libraries such as TanStack Query
• Daily, hands‑on use of agentic AI coding tools (Claude Code, Cursor, Copilot Workspace, Codex or similar) – you’ll demo your workflow live
• Testing discipline: Jest or Vitest, React Testing Library, Playwright or Cypress, xUnit or NUnit
• Docker and Docker Compose, Git, CI/CD (Azure DevOps, GitHub Actions or similar)

Additional skills – the edge you have

• Payments, card processing, risk/fraud or financial services experience, ideally with PCI-scoped applications
• Design systems and component libraries (MUI, Fluent UI) and Storybook
• Advanced data visualization (D3, time-series and distribution charts) or UIs for LLM-backed features
• Identity in SPAs: OAuth2/OIDC, MSAL / Microsoft Entra ID
• Prior consulting or staff‑augmentation experience embedded in a client team

Additional Information

What we offer:

• Flexible and remote cooperation options
• International projects with leading global clients
• Travels related to international projects
• Non-corporate atmosphere
• Access* to language classes
• Access* to knowledge-sharing initiatives
• Access* to private healthcare and life insurance
• Access* to multisport card

*The availability and terms of individual benefits may vary depending on the chosen form of cooperation.