Full Stack Developer – Java, Kotlin

GreenPocket GmbH

Full Stack Java/Kotlin Developer in an agile startup addressing climate change through energy management solutions. Collaborate with teams to enhance SaaS applications and ensure product quality.

Posted 5/10/2026full-timeKöln • 🇩🇪 GermanyMid-LevelSeniorWebsite

Tech Stack

Tools & technologies

JavaJavaScriptKotlinMicroservicesSpringTypeScript

About the role

Key responsibilities & impact

Together with the development team, product owners and UX/UI designers, you drive the further development of our SaaS solutions (with a focus on interfaces)
You design, test, maintain and continuously improve the software independently and as part of your team
You advise product management on technical matters and coordinate with them and the business domain on functional and technical requirements and their implementation
In the DevOps area, you increasingly take co-responsibility for architecture, programming and testing
Through pair programming, code reviews and prototyping you not only develop our products but also continuously advance your own skills
You regularly exchange ideas as part of “DevComs” or our Architecture Board with our agile, interdisciplinary teams
You look beyond your immediate scope, realize your ideas during monthly GreenDays and have the opportunity to feed these ideas into product development

Requirements

What you’ll need

You have completed a degree in an IT-related field or a comparable qualification that convinces us
You already have initial experience as a software developer, ideally in a SaaS environment
You have practical experience with microservices and cloud infrastructures
You have extensive Java or Kotlin knowledge, ideally in the Spring context. Alternatively, you bring very good JavaScript/TypeScript skills and experience with common frameworks
You are familiar with standard tools used in agile environments, such as JIRA and Confluence, for managing and documenting development
As a creative, analytical thinker you enjoy working with new technologies and have a strong quality awareness
You embrace the startup mentality, are motivated and like to take initiative
You have good German and very good English language skills

Benefits

Comp & perks

Intensive coaching and training opportunities as well as participation in the DevCom and the Architecture Board
A permanent employment contract with the opportunity to help shape the green startup scene
Startup atmosphere with plenty of room to shape things, flat hierarchies and short decision-making paths
Flexible working hours and, of course, the option to work from home
Take your GreenDay! Leave the daily routine behind and dedicate one day each month entirely to your own ideas
Regular team events (bouldering, board and online game nights, etc.) and daily foosball tournaments with ambitious colleagues aka foosball pros
An office full of sprint memes and day-specific playlists (for example, Fridays always end with the “Good Vibes” playlist)
Unlimited coffee and water supplies as well as regular fresh fruit
Located in an area with excellent cultural, sporting and transport connections

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

JavaKotlinJavaScriptTypeScriptSpringmicroservicescloud infrastructureSaaS developmentpair programmingcode reviews

Soft Skills

analytical thinkingcreativityinitiativequality awarenessteam collaborationcommunicationproblem-solvingadaptabilitymotivationinterdisciplinary teamwork