Senior Node Developer

Altimetrik Poland is a digital enablement company. We deliver bite-size outcomes to enterprises and startups from all industries in an agile way to help them scale and accelerate their businesses. We are unique in Poland's IT market. Our differentiators are an innovation-first approach, a strong focus on core development, and an ability to attack the challenging and complex problems of the biggest companies in the world.

For one of our clients in the payment industry, we are looking for a Senior Node Developer.

Hybrid work - 3 days in the office in Warsaw

Responsibilities:

• Payment Integration: Payment providers (PayPal, Stripe, Klarna), authorization/capture/refund flows, 3D Secure, PCI-DSS compliance.

• API & Security: RESTful API design with versioning, Joi validation, JWT/OAuth2 authentication/authorization, RSQL query languages.

• Server-Side Rendering: Pug templates, HTML/CSS, SASS/PostCSS, iframe-based widget embedding.

• Fintech Domain: Checkout flows, transactions, refunds, multi-currency, fraud detection, high availability.

If you possess:

• TypeScript & Node.js: Strong TypeScript 3.x+ and Node.js 16+ production experience, async/await, decorators, performance optimization.

• Frameworks & Architecture: Hapi.js or similar (Express, Fastify, NestJS), Clean Architecture, Dependency Injection (InversifyJS), Repository Pattern, DDD.

• Database & Caching: MongoDB (modeling, indexing, performance tuning), Redis, database migrations.

• Development Practices: Agile/Scrum, SOLID principles, Git workflows, CI/CD, testing (Mocha/Chai/Sinon or Jest, Cypress).

Nice to Have:

• Fintech Experience: Payment processing, e-commerce, checkout flows, transactions, refunds, multi-currency.

• Angular or React with RxJS/state management (NgRx, Redux) for frontend modernization.

• AWS (EC2, S3, Secrets Manager, CloudWatch), Docker/Docker Compose.

• Webpack, AppDynamics/APM tools.

• Message queues (Kafka, RabbitMQ, Redis Pub/Sub).

• Internationalization (i18n) systems.

• Experience with Puppeteer for PDF/receipt generation.

Professional Skills:

• Strong problem-solving and production debugging abilities.

• Ownership mentality with focus on security, quality, and performance.

• Excellent cross-functional communication.

• Code review and mentoring experience.

🔥We grow fast.

🤓We learn a lot.

🤹We prefer to do things instead of just talking about them.

If you would like to work in an environment that values trust and empowerment... don't hesitate, just apply!