Senior React Developer (with Polish B2+) Warsaw

Project Description:

Do you want to take part of mobile revolution in banking area? We are looking for skilled Senior React developer to develop application that ... most provably you are already using! Sounds interesting?
- Application has 4.8 stars on App Store and Google play with more than 300 thousand opinion and more than 1 million downloads per platform.

- The team is continuously updating the app with new features recommended by newest operating system standards

- Thanks to a large number of users after each release developers are getting instant-feedback about it on the stores

- Agile team (18 people) include dedicated testers that are testing every feature

- 2 weeks sprints

- Every developer has possibility to share his thoughts and ideas about new features to the client

Responsibilities:

You would take part of development of banking mobile, backend and backoffice applications, new features, bug fixing.
Team responsible for new features is organized into smaller teams 2-4 developers that are responsible for one larger functionality.

Mandatory Skills Description:

1. Senior-level frontend with React + TypeScript - application architecture, hooks, state management, routing, performance, typing, reusable components, micro frontends.
2. End-to-end quality and testing - frontend testing (Jest/RTL), E2E (Cypress/Playwright), contract testing (e.g., Pact) + a sensible test strategy.
3. Application security - OAuth2/OIDC, SSO, JWT, roles/permissions model, OWASP Top 10, secure coding, data protection, CSP, XSS, CSRF, secure storage, dependency security (npm audit/SCA).
4. CI/CD and delivery mindset - pipelines (GitHub Actions/GitLab/Jenkins), quality gates, FE/BE builds, test automation, versioning, release management, feature flags.
5. Docker fundamentals - containerization, environment configuration, secrets, logs/metrics, deployments; ability to diagnose issues across environments.
6. Observability and troubleshooting - logging (structured logs), metrics and tracing, ability to do fast root-cause analysis after incidents.
7. Senior soft skills + engineering leadership - meaningful code reviews, mentoring, proposing solutions and trade-offs, communication with business/PO, ownership of a module/product and delivery accountability.

Nice-to-Have Skills Description:

Knowledge of Java (17/21) + Spring Boot - designing REST APIs, validation, transactions, error handling, security, integrations (HTTP, messaging).

Languages:

Polish: C2 Proficient