Junior/Mid FullStack Developer with Blockchain

Join our team as:Junior/Mid FullStack Developer with Blockchain

KRAKÓW|HYBRID

We’re looking for a Junior/Mid-level FullStack Blockchain Developer! Are you passionate about building modern web applications and curious about how things work under the hood of blockchain systems? Join our team and help us develop tools that make interacting with on-chain data and smart contracts more accessible and transparent. We’re looking for a FullStack Developer to help bring them to life!

Junior/Mid FullStack Developer with Blockchain

PLN 8,000 - 16,000 NET ON B2B

RequirementsWho are we looking for?

Basic tech stack

React
TypeScript
Node.js
NestJS
Material UI
REST
Docker
AWS

Great, if you know

Rust
Stellar Blockchain
Postgres

Important traits

Basic understanding of how frontend and backend applications are structured, ideally with some exposure to AWS services
Familiarity with React and TypeScript
Basic knowledge of Rust and a strong willingness to learn it
Comfortable working with APIs (REST and/or GraphQL)
Basic understanding of blockchain concepts and an experience or interest in applied cryptography
Comfortable using AI coding tools (e.g. Claude Code), we use them a lot these days
Excellent communication skills and team spirit
Openness to learning new tools and technologies
Understanding of when not to fully rely on an AI agent
Proficiency in spoken English, as it is our working language

ResponsibilitiesWhat you'll do?

Build and develop fullstack applications (React, Rust, AWS)
Work on real blockchain / Web3 projects
Integrate frontend and backend with blockchain data
Design and implement APIs indexing and data processing logic
Work closely with a product team and communicate in English on a daily basis

Our offerWhat’s in it for you?

Paid holidays

Training budget

Private healthcare

Non-Corporate culture

A hybrid work environment with flexible hours

Multisport Plus or gym and swimming pool pass for a facility located just across the street

A supportive team that loves sharing knowledge

About the projectWhat project you’ll be working on?

You may join one of our blockchain projects, such as building tools around the Stellar / Soroban ecosystem, including a smart contract block explorer. Your work will focus on making on-chain data more accessible and understandable - helping developers and users explore transactions, contracts, and blockchain activity in a clear and meaningful way. We don’t expect you to have experience with these particular technologies, as these are quite niche. What we do expect is that you’re eager to learn and explore. At Rumble Fish, we work on a variety of projects across blockchain, cloud, and AI, so depending on the project, you may also have the opportunity to explore different technologies and domains over time. If you're excited about building real products, working with modern technologies, and growing your skills in the Web3 space - let’s talk!

Recruitment process

Check our recruitment process

Learn more about the recruitment process at Rumble Fish. Our HR team will accompany you every step of the way.

1

Send us your application

Start by sending us your resume so we can get an overview of your experience and skills.

2

Phone screening

If your CV matches the profile, we’ll arrange a 15-minute interview to get to know each other better.

3

Recruitment task

We’ll give you a task so that you can showcase your skills. We can skip this step if you’ll show us some of your amazing code.

4

Meeting in the office

Now we invite you to our office in Kraków for a technical interview. We can also do it online.

5

The result

We’ll inform you about our decision within a few days.

Let's collaborate

Apply now for this position!Don’t see a suitable position? We’re always looking for talent, so feel free to get in touch!Do you prefer e-mail?
jobs@rumblefish.pl

Full Name

Email

Message

Upload CV

I wish to receive Rumble Fish email communication.I accept Rumble Fish Privacy Policy

RUMBLEFISH POLAND SP Z O.O.Filipa Eisenberga 11/3 31-523 Kraków, Polska

NIP: 6772425725REGON: 368368380KRS: 0000696628

P: +48 601 265 364E: hello@rumblefish.dev