FinTech Client #4 | Full Stack Developer

SD Solutions; Warszawa; On-site; PLN 150,000 - 210,000; Full time

Job summary

FinTech Client #4 is partnering with SD Solutions to hire a talented Full-Stack Developer to build and maintain a self‑service merchant onboarding platform.

You will collaborate with analysts, QA, and engineers, work with Node.js, React, NestJS, and AWS, and apply best practices to deliver scalable solutions.

This role demands 5+ years of experience, fluent English, and a proactive, solution‑oriented mindset in an international setting.

Qualifications

• 5+ years of experience in web application development (Node.js, React).
• Experience integrating third‑party APIs and managing databases.
• Strong knowledge of RESTful APIs and modern web architectures.
• Experience in agile SDLC methodologies (Scrum/Kanban) and observability tools.

Responsibilities

• Collaborate cross‑functionally with Business Analysts, QA, and other team members to achieve elegant solutions which satisfy business needs, goals, and objectives.
• Work alongside other Software Engineers on the team to elevate technology and apply best practices for the project and software engineering concepts.
• Participate in and improve development processes and technical solutions; test code via unit tests to ensure delivery and quality goals are met.
• Diagnose and resolve issues with deployed systems using various techniques including direct engagement with support personnel and customers.
• Participate in tech grooming and/or requirements gathering/validation sessions.

Skills

English fluency

Cross-team communication

Deadline management

International experience

Tools

Node.js

React

NestJS

Express.js

TypeScript

JavaScript

PostgreSQL

MSSQL

Git

Docker

Jest

Tailwind CSS

AWS

Job description

On behalf of FinTech Client #4, SD Solutions is looking for a talented Full-Stack Developer.

The Global Merchant Application team is developing and maintaining a self‑service platform for automated merchant onboarding, used by commercial teams (internal sales and external partners). This unified and scalable platform empowers partners and sales representatives to seamlessly submit and manage merchant applications through a single streamlined system. It replaces fragmented tools with an integrated solution that delivers speed, consistency, and efficiency—enabling faster merchant onboarding, an improved partner experience, and greater operational alignment. This is one of the top projects in the company at the moment. The team also works with multiple integrations, which is critical for FinTech Client #4 when a company is growing extremely fast.

SD Solutions is a staffing company operating globally. Contact us to get more details about the benefits we offer.

Responsibilities

• Collaborate cross‑functionally with Business Analysts, QA, and other team members to achieve elegant solutions which satisfy business needs, goals, and objectives.
• Work alongside other Software Engineers on the team to elevate technology and consistently apply best practices as they relate to the project and general software engineering concepts.
• Participate in and make improvements in the continuous improvement of development processes and technical solutions. Test code via unit testing to ensure delivery and quality goals are met.
• Diagnose and resolve issues with deployed systems using a variety of techniques including direct engagement with support personnel and customers.
• Participate in tech grooming and/or requirements gathering/validation sessions.

Requirements

• 5+ years of experience in web application development (Node.js, React)
• Proven experience integrating third‑party APIs and managing databases
• Solid background in system maintenance, support, and incident response
• Practical knowledge of agile SDLC methodologies (Scrum/Kanban)
• Proficiency with observability tools (DataDog, Sentry, AWS CloudWatch)
• Strong understanding of RESTful APIs
• Demonstrated ability to lead technical analysis and coordinate cross‑team communication
• Ability to juggle priorities and meet deadlines
• Experience in international contexts and fluent English (written and spoken)

Technical Skills Required

• Programming Languages: TypeScript, JavaScript
• Backend Framework: NestJS, Express.js
• Frontend Technologies: React 18+, Next.js
• Database: PostgreSQL, MSSQL (or any other relational database)
• ORM: TypeORM, Sequelize
• Version Control: Git
• Containerization: Docker
• Testing: Jest for unit and e2e testing
• Styling: Tailwind CSS
• Linting and Formatting: ESLint, Prettier
• Caching: Redis
• Cloud: AWS
• AI: Claude Code

Advantages

• Experience working on integration with Salesforce
• Knowledge of AWS services

About the company

A global fintech company providing unified payment infrastructure and financial services for merchants and consumers worldwide. The platform integrates multiple payment channels into a single solution, combining in‑house technology development and product innovation to streamline transactions at scale.