Senior Full-stack Developer

your Jared; Kraków; Hybrid; PLN 210,000 - 320,000; Full time

Benefits offered by this job

Health insurance

Multisport

Shopping vouchers

Employee Stock Purchase Plan (15% off)

Job summary

your Jared is seeking a Senior Full-stack Developer to build a product using Python/FastAPI on the backend and React/TypeScript on the frontend. The stack includes PostgreSQL, OpenSearch, and Databricks in a multi-cloud setup, with a strong emphasis on GenAI-enhanced workflows.

You will design and maintain APIs, optimize high-load queries, and contribute across the stack in a hybrid, startup-like environment. English proficiency is required (B2+).

Qualifications

• 5+ years of production experience with Python, FastAPI, and SQL.
• Experience in web application development, API design, and integrations.
• Proficiency in handling high-load databases and query performance optimization.
• Front-end development with TypeScript and React; full-stack willingness.
• Hands-on experience with GenAI engineering tools, Claude Code preferred.
• Strong communication and proactive work style.

Responsibilities

• Develop and maintain web applications using Python/FastAPI and SQL.
• Design APIs and integrations to support high-load database operations.
• Optimize query performance across production systems.
• Contribute to front-end development using TypeScript and React.
• Apply GenAI engineering tools to improve development workflows and collaborate with the team.

Skills

Python

FastAPI

SQL

API design

TypeScript

React

GenAI tools

Claude Code

Communication

Ambiguity handling

Tools

PostgreSQL

OpenSearch

Databricks

PySpark

Job description

We are looking for a Senior Full-stack Developer to join a team building a new product that uses Python and FastAPI on the backend, React and TypeScript on the front end, and PostgreSQL and OpenSearch for database management. The product operates in a multi-cloud environment and makes heavy use of Databricks.

Responsibilities

• Develop and maintain web applications using Python/FastAPI and SQL
• Design APIs and integrations that support high-load database operations
• Optimize query performance across production systems
• Contribute to front-end development using TypeScript and React
• Apply GenAI engineering tools to improve development workflowsCollaborate with the team while also working autonomously on assigned tasks
• Communicate proactively with team members and stakeholders
• Take ownership of product features and drive meaningful contributions beyond ticket completion
• Navigate ambiguity and deliver results in a fast-paced startup environment

Requirements

• 5+ years of production experience with Python, FastAPI, and SQL
• Expertise in web application development, API design, and integrations
• Proficiency in handling high-load databases and query performance optimization
• Familiarity with front-end development using TypeScript and React, with willingness to work full-stack
• Hands-on experience with GenAI engineering tools, ideally Claude Code
• Strong communication skills and proactivity, with the ability to work both independently and within a team
• Capability to deal with ambiguity and get things done without constant direction in a transparent, fast-moving startup environment
• English proficiency at B2 level or higher

Nice to have

• Solid experience with TypeScript, React, Next.js, Storybook, Playwright, Radix UI, and Zustand
• Experience with PostgreSQL and OpenSearch
• Familiarity with cloud platforms, Infrastructure as Code, and related tools
• Background in data engineering, handling data with PySpark and SparkSQL
• Client-facing experience

We offer

Top tech minds driving innovation in AI, cloud and digital platform modernization

Supportive team and agile, startup-like culture

Hybrid-by-design mode and opportunity to work remotely within Poland

Chance to work abroad for up to 60 days annually

Business-driven relocation opportunities

Career development programs

Thought leadership, mentoring, soft skills, and well-being programs

Certification opportunities: Anthropic, Gemini, GCP, Azure, AWS

English classes

Stable pay

Participation in the Employee Stock Purchase Plan with a 15% discount

Benefits

• Benefits package, including health insurance, multisport, and shopping vouchers
• Referral bonuses up to $2,000
• Offices featuring entertainment and relaxation zones, table tennis and football, free snacks, coffee, and more
• Corporate, social, and well-being events
• Benefits listed above are available to employees only.
• Contractor cooperation is also available; terms of B2B cooperation agreements are agreed individually.