Senior Fullstack Engineer (HUMAN) full-time remotehybrid (Düsseldorf, Germany)

freshcells systems engineering GmbH; Düsseldorf; Hybrid; EUR 55.000 - 75.000; Vollzeit

Zusammenfassung

A dynamic software service provider in Düsseldorf is seeking a Senior Fullstack Engineer to join their innovative team. This role offers the flexibility of hybrid or remote work. You will be responsible for developing and maintaining complex backend APIs while collaborating with team members to influence code structure and testing. Ideal candidates will have strong knowledge of ES6 JavaScript, ReactJS, and experience with databases and RESTful services. Join us in creating impactful software solutions.

Qualifikationen

• Very good knowledge of ES6 JavaScript.
• Strong knowledge of frameworks and libraries such as ReactJS and/or Angular.
• Sound experience with relational or non-relational databases.
• Good knowledge of data-structure design.
• Competence in consuming and creating web services based on REST and especially GraphQL.
• Know-how in performance optimisation.
• Basic knowledge of HTML and CSS is helpful.
• Experience with agile development in a team.
• Hands-on experience with automated software testing.
• Basic knowledge of API security.
• Fluent in English.

Aufgaben

• Develop and maintain backend APIs using complex frontend behaviors with React.
• Work across a shared client-customizable codebase.
• Recognise emerging patterns, craft reusable abstractions and refactor responsibly.
• Influence structure, testing and performance in the codebase.
• Contribute to technical decision-making, not just execute tickets.

Kenntnisse

ES6 JavaScript

ReactJS

Angular

Relational databases

Non-relational databases

REST

GraphQL

Performance optimisation

HTML

CSS

Agile development

Automated software testing

API security

Fluent English

Tools

PHP

Symfony

Laravel

Yii

Docker

Kubernetes

OpenShift

Docker Swarm

Jenkins

TypeScript

Jobbeschreibung

freshcells systems engineering GmbH is a software service provider based in Düsseldorf with a dynamic team of over 50 creative experts from various fields.

We focus on authenticity, individual talent development and open communication. We build on respect, trust and responsibility. As an innovation-driven company we invest in new ideas. We know that the best results are achieved as a team. We make mistakes but we learn from them. We are open and courageous for new ways.

Join us on our exciting journey in what is probably the most important and forward‑looking area – software development – as a Senior Fullstack Engineer (m / f / d) in full‑time hybrid or remote.

We hire people who want to understand how things work, not just how to wire them together. You don’t have to know everything, but you should want to know why.

We’re seeking a person who thinks like an engineer:

• Sees code as part of a system, not just a task
• Cares deeply about clarity, naming and tradeoffs
• Wants to understand why something works, not just that it does
• Feels uneasy when the wrong abstraction appears repeatedly
• Can clearly explain concepts to a junior dev, PM or their future self

We don’t expect triviality; we do expect curiosity and solid mental models. You should be familiar with:

• Why “false” in JavaScript
• What happens if you pass a new object in a React hook dependency array
• How closures work and why they matter
• Avoiding side effects that break memoization
• Why abstraction is about boundaries, not just DRY

If you already care about reference semantics, testability or naming, you’ll feel at home here.

Tasks

• Develop and maintain backend APIs using complex frontend behaviors with React
• Work across a shared client‑customizable codebase
• Recognise emerging patterns, craft reusable abstractions and refactor responsibly
• Influence structure, testing and performance in the codebase
• Contribute to technical decision‑making, not just execute tickets

Requirements

• Very good knowledge of ES6 JavaScript
• Strong knowledge of frameworks and libraries such as ReactJS and/or Angular
• Sound experience with relational or non‑relational databases
• Good knowledge of data‑structure design
• Competence in consuming and creating web services based on REST and especially GraphQL
• Know‑how in performance optimisation
• Basic knowledge of HTML and CSS is helpful
• Experience with agile development in a team
• Hands‑on experience with automated software testing
• Basic knowledge of API security
• Fluent in English

Nice to have:

• Experience with PHP, ideally with frameworks such as Symfony, Laravel or Yii
• Experience with containerisation technologies such as Docker etc.
• Experience with container orchestration tools like Kubernetes, OpenShift or Docker Swarm
• Knowledge of designing and adapting software to be twelve‑factor applications
• Knowledge of continuous integration via tools like Jenkins
• Experience with TypeScript

All people are welcome here regardless of gender, age, sexual identity, origin, religion, ideology, with or without a disability. The main thing is that you fit in with us.

If you are interested in a wide‑ranging portfolio of projects, want to continuously develop yourself and enjoy working independently and responsibly, get in touch with us: recruiting at freshcells dot de. We look forward to hearing from you!