Senior Frontend Engineer – API/Interface Design

42dot; Warszawa; On-site; PLN 180,000 - 260,000; Full time

Job summary

42dot in Warsaw is seeking a Senior Frontend Engineer to shape the user-facing layer of our SDV platform. You will build real-time dashboards, 3D vehicle views, and partner portals with React and TypeScript.

You will design OpenAPI-driven APIs, implement streaming interfaces (SSE/WebSocket), and collaborate with product and design to deliver a high-quality developer experience.

Qualifications

• Bachelor's degree in Computer Science or related field.
• 5+ years of production experience with React and TypeScript, including end-to-end type safety.
• Hands‑on experience designing and evolving OpenAPI 3.x specifications and the tooling around them (validators, mocks, client generators).
• Strong schema-first instincts (Zod, JSON Schema, runtime validation at boundaries).
• Solid working understanding of REST and streaming protocols (Server‑Sent Events, WebSocket).
• Practical experience integrating 3D content in the browser with three.js or react-three-fiber: scenes, cameras, glTF loading, basic performance tuning.
• Strong code review culture and ability to collaborate with backend and design counterparts.
• Fluent English.

Responsibilities

• Design, document and evolve the public REST and Server-Sent Events API surface of our virtual vehicle platform, including OpenAPI specifications and generated partner clients.
• Implement and maintain the production frontend in React and TypeScript: real-time vehicle state dashboards, vehicle variant management, partner-facing portals, configuration and scenario tooling.
• Integrate 3D vehicle assets (glTF) into the frontend using three.js or react-three-fiber, in close collaboration with our product designer.
• Build the developer experience around the schema: typed clients, runtime validation, mocks, contract tests, generated documentation.
• Own resilience of streaming UI components: reconnection, backpressure, multiplexed event handling.
• Participate directly in technical conversations with external integration partners, including API design reviews and partner-facing written guides.

Skills

React

TypeScript

OpenAPI

Zod

JSON Schema

REST

Server-Sent Events

WebSocket

three.js

react-three-fiber

English

Playwright

Cypress

Code review

Education

Bachelor's degree in Computer Science or related field

Tools

OpenAPI tooling

typed clients

Job description

Overview

Join our dynamic team as a Senior Frontend Engineer, where you will shape the user-facing layer of our virtual development platform for Software Defined Vehicles (SDV). Your work will define how internal engineering teams and external integration partners experience our SDV OS tooling - from the public API contract that drives partner integrations, through the real-time dashboard that visualizes vehicle state, to the 3D model views that bring the virtual vehicle to life.

Role and Responsibilities

• Design, document and evolve the public REST and Server-Sent Events API surface of our virtual vehicle platform, including OpenAPI specifications and generated partner clients.
• Implement and maintain the production frontend in React and TypeScript: real-time vehicle state dashboards, vehicle variant management, partner-facing portals, configuration and scenario tooling.
• Integrate 3D vehicle assets (glTF) into the frontend using three.js or react-three-fiber, in close collaboration with our product designer.
• Build the developer experience around the schema: typed clients, runtime validation, mocks, contract tests, generated documentation.
• Own resilience of streaming UI components: reconnection, backpressure, multiplexed event handling.
• Participate directly in technical conversations with external integration partners, including API design reviews and partner-facing written guides.

Qualifications, Experience and Skills

• Bachelor's degree in Computer Science or related field, equivalent practical experience.
• 5+ years of production experience with React and TypeScript, including end-to-end type safety.
• Hands‑on experience designing and evolving OpenAPI 3.x specifications and the tooling around them (validators, mocks, client generators).
• Strong schema-first instincts (Zod, JSON Schema, runtime validation at boundaries).
• Solid working understanding of REST and streaming protocols (Server‑Sent Events, WebSocket).
• Practical experience integrating 3D content in the browser with three.js or react-three-fiber: scenes, cameras, glTF loading, basic performance tuning.
• Strong code review culture and ability to collaborate with backend and design counterparts.
• Fluent English.

Preferred Qualifications

• Frontend integration testing with Playwright or Cypress, including visual regression workflows.
• Experience writing partner- or developer-facing technical content (HOWTOs, integration guides, release notes).
• Working experience with multi‑site, multi‑national and multi‑contributor teams.
• Knowledge of automotive products, is a plus but not required.

Equal Opportunity Statement

42dot is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees, regardless of race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, or veteran status.