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JetBrains

Staff Software Developer (Kotlin Libraries)

JetBrains
Spain · Full-time · Not Applicable

We are looking for an experienced developer to help us shape the future of the Kotlin ecosystem.

As Part Of Our Team, You Will

  • Create and maintain foundational libraries for Kotlin core primitives that are used by hundreds of thousands of developers
  • Become an expert in specific domains of computer science and software engineering
  • Be part of a design committee that decides how the Kotlin API should be shaped
  • Participate in creating standard Kotlin tools, specifications and language features

Preferable

  • JVM development experience down to the implementation details of the Java standard library
  • Strong understanding of the domain you've been working with
  • Ability to write design documents for complex systems with strong reasoning behind each trade-off and technical decision
  • Experience in performance engineering or API design

In general, if you see yourself reading a Unicode standard, exploring how five other languages transform strings to bytes, figuring out why some Oceania islands changed their timezone from -10:00 to +14:00 and whether it should be expressed in the API of Kotlin timezones, optimizing interface hierarchy to be more JIT-friendly and is not afraid of re-iterating over documentation a multitude of times, you won't get bored in our team.

Why join JetBrains?

  • Strong base salary. We offer competitive pay that reflects your skills and experience.
  • Flexible work location. Enjoy the freedom to work from home or from the office.
  • Remote work. Spend up to 30 days per year working remotely from abroad.
  • Extra time off. More days to relax, recharge, and do the things you love.
  • Medical insurance allowance. Enjoy peace of mind for you and your family.
  • Learning and development opportunities. Access to conferences, courses, and language classes.
  • Language classes. Pick up the local language or sharpen your English skills.
  • Fuel your day. Enjoy a hot meal or receive a lunch allowance on workdays.
  • Mental health support. To help you feel your best, we provide easy access to professional mental health services.
  • Sports benefit. Enjoy an on-site gym or sports club stipend.
  • Internal events. Join company-wide celebrations and team gatherings.
  • Some benefits may vary depending on location.

We are an equal opportunity employer

We know great ideas can come from anyone, anywhere. That’s why we do our best to create an open and inclusive workplace – one that welcomes everyone regardless of their background, identity, religion, age, accessibility needs, or orientation.

We process the data provided in your job application in accordance with the Recruitment Privacy Policy.

Key Skills

Ranked by relevance

kotlin java
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Posted
May 08, 2026
Type
Full-time
Level
Not Applicable
Location
Madrid
Company
JetBrains

Industries

Software Development

Categories

Engineering Information Technology

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