Senior Full-Stack Engineer

Retenza; United States; Hybrid; USD 60,000 - 105,000; Full time

Benefits offered by this job

Remote-friendly within EU

Competitive compensation

Job summary

Retenza is seeking a senior full-stack engineer to own features from API design to UI, combining frontend and backend work with AI/LLM integrations. The role emphasizes relational data modeling, scalable architecture, and end-to-end delivery using Next.js, TypeScript, PostgreSQL, Redis, and AI services.

The candidate will work on high-throughput systems, integrate AI APIs, and contribute to scaling the core platform, with a full-time arrangement based in Warsaw or remote within the EU.

Qualifications

• At least five years of professional software engineering experience.
• Strong TypeScript and React skills.
• Experience with PostgreSQL and relational database design.
• Familiarity with AI or LLM APIs such as Claude, OpenAI, or similar services.
• Experience with high-throughput queue technologies such as BullMQ or SQS.

Responsibilities

• Deliver features end to end, from shaping APIs to implementing the interface.
• Build and maintain application functionality with TypeScript and React.
• Work with PostgreSQL and design relational data structures.
• Integrate AI or large language model APIs into product workflows.
• Support asynchronous processing through high-throughput queue systems.
• Contribute to scaling the core platform.

Skills

TypeScript

React

Relational data design

AI/LLM APIs

5+ years experience

Tools

BullMQ

SQS

PostgreSQL

Next.js

Job description

Role overview

Build and scale a software platform by owning product features from initial API design through the user interface. This is a senior full-stack engineering role combining frontend and backend development, relational data work, and integrations with AI services and queue systems.

Responsibilities

• Deliver features end to end, from shaping APIs to implementing the interface.
• Build and maintain application functionality with TypeScript and React.
• Work with PostgreSQL and design relational data structures.
• Integrate AI or large language model APIs into product workflows.
• Support asynchronous processing through high-throughput queue systems.
• Contribute to scaling the core platform.

Requirements

• At least five years of professional software engineering experience.
• Strong TypeScript and React skills.
• Experience with PostgreSQL and relational database design.
• Familiarity with AI or LLM APIs such as Claude, OpenAI, or similar services.
• Experience with high-throughput queue technologies such as BullMQ or SQS.

Benefits and work setup

Full-time position based in Warsaw or remote within the EU. The described stack includes Next.js, TypeScript, PostgreSQL, Redis, and an LLM API.