Backend java developer

Salary Competitive

Trendsales is an online marketplace for buying and selling 2nd-hand items.

Through our apps on iOS, Android and the web, we make it convenient for sellers to list their used items and easy for buyers to find what they are looking for. This is the discovery part of our marketplace.

To facilitate all purchases, we have built an end-to-end payment, shipping and insurance solution that is secure and fast for both sellers and buyers.

  • Buyers are protected all the way from making the initial payment until after they have received their items. We even have an entire support team on standby!

  • Sellers receive their money right after they have handed in their package for shipment. No address needed. Just a shipping code provided through the app. Sellers can also enable "Buy now" on their listings, making it even easier to sell.

The is the transactional part of our platform and the core of our business.

We are very proud of both the discovery and transactional parts of the platform, yet there are so many things that can be improved, expanded and added that will make the experience even better (more categories and shipping providers, personalization, recommendation engine and login-free purchases to name just a few)

Most of that centers around the backend and this is where you come in.

The stack and the role:

All 3 frontends communicate with our backend using a Java SpringBoot REST API, which you will be a part of expanding and maintaining.

The backend is hosted on AWS with key components being EC2, Elastic Beanstalk, Aurora (MySQL) and ElasticSearch. We use GitHub for versioning control and Github Actions for continuous integration.

The backend team currently consists of 4 software engineers.



  • Build: Together with the product team, spec and develop new features

  • Deploy: Ensure deployment of backend features built by you works as expected

  • Maintain: Keep the platform stable by fixing bugs and optimizing performance


You will fit perfectly in this role if you:

  • 3+ years of relevant professional experience (required)

  • Have strong competencies in software design

  • Have good java skills

  • Have hands-on experience with SpringBoot

  • Have strong knowledge of relational databases

  • Have basic knowledge of AWS or similar cloud platforms

You also have:

  • A high learning ability and natural curiosity

  • An ability to communicate fluently in English speaking, reading and writing

  • An interest in 2nd-hand


Our office is based in central Copenhagen, Denmark but this position is also open to remote work from anywhere in Denmark as long as you can come to the office 1-3 times per week on average.

For more information or questions please contact us at

Perks and benefits

This job comes with several perks and benefits

Flexible working hours
Flexible working hours

Time is precious. Make it count. Morning person or night owl, this job is for you.

Free coffee / tea
Free coffee / tea

Get your caffeine fix to get you started and keep you going.

Near public transit
Near public transit

Easy access and treehugger friendly workplace.

Social gatherings
Social gatherings

Social gatherings and games; hang out with your colleagues.

Free office snacks
Free office snacks

Peckish after lunch? We got your back with soft drinks, treats and fruit.

Free friday beers
Free friday beers

Friday is something special, let's enjoy a beer together.

See all 12 benefits

Working at

At Trendsales, we are committed to making 2nd the preferred way of shopping. Every day we work on making it ever cheaper and more convenient for buyers and sellers – good for our users and for the planet. We love to have fun. Not teenage-giggly fun, not dad-joke-fun. We just like to challenge the pretentious fashion industry and support our users in pushing the boundaries for fashion and free them from dress code dogmas. We want them to find their own unique style using our great platforms and flea markets. We applaud everyone who chooses a more sustainable way of shopping and we do our part as a company. We are a team of about 60 passionate product-, support- and marketing professionals and we can't wait to hear from you.

Read more about Trendsales

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