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Kotlin Engineer – (Senior/Staff)

Kotlin Engineer – (Senior/Staff)
B2B140 - 185 PLN NET PER HOUR
LOCATION + Remote Poland: Kielce, Kraków, Wrocław
Apply now

VirtusLab is a leading European software consulting and engineering company. Our mission is to craft clean code and practical solutions with precision and purpose. We foster a dynamic culture rooted in strong engineering, a sense of ownership, and transparency, empowering professionals to make a substantial impact in the software industry.

About the Project & Scope of Services

Project collaboration opportunity for Engineers interested in co-creating advanced tooling using mainly Kotlin. The cooperation focuses 100% on technology, targeting developers as the ultimate end-users. The services will be delivered within a small, flexible team, offering high operational autonomy. The scope of services includes: designing, scoping, testing, and implementing software solutions, while providing expertise for an organisation specialized in developer tooling. Key focus areas involve working on IntelliJ plugins, IDEs, coding agents, and frameworks for Local AI inference.

Kotlin/Java Expert
Kotlinx.coroutines / concurrent programming Advanced
Compose Desktop (Jetpack Compose) Nice to have
Kotlin multiplatform Nice to have
Build tools/IDE development Nice to have
English Advanced
View available projects
Project
Local Inference Platform
Project Scope

Building a desktop application for deploying and configuring local inference on local devices (e.g., NVIDIA Spark / DGX Spark), managing model lifecycle (start/stop), and connecting coding agents like Claude Code and Codex to locally hosted models. Currently an internal MVP, on the road to open source.

Tech Stack

  • Core: Kotlin, Compose Desktop (with JetPack Compose roots), kotlinx.coroutines, REST APIs for model deployment management

  • Agent Layer: Configuration files in TOML/JSON/YAML, LLM proxy routing from agents to BE

  • Packaging: Native installers — MSI (Windows), DEB (Linux), DMG (macOS)

Challenges

  • Building a desktop control plane for local AI agents that abstracts away the messy parts of running LLMs on heterogeneous hardware — model lifecycle, proxy routing, agent configuration, and OS-specific quirks (path separators, signing, packaging) — while keeping the system extensible enough to evolve toward open source.

  • Visualising model statistics and system load on top of a backend handling the deployment.

Team Environment

Cooperation with a small, startup-like team on the JetBrains side — zero bureaucracy, direct feedback loops from potential users, and fast iteration cycles. Code reviews are integrated as a standard quality assurance practice.

Project
IDE's Development & Optimization

The project focuses on building and enhancing IDEs and core plugins within the JetBrains platform, powering renowned tools such as IntelliJ, PyCharm, GoLand, PHPStorm, RubyMine, and more. The scope of services involves implementing advanced support for technologies and languages including PHP, Ruby, Scala, Bazel, or Kotlin by deep integration with their respective ecosystems. The ultimate objective is delivering stable, high-quality tools that optimize the daily workflows of developers globally.

Tech stack

Kotlin, Java, Kotlin Coroutines, technology specific to the IDE/Plugin (e.g Ruby for RubyMind)

Project Team Composition

The core engineering team consists of senior-level experts focused on specific JetBrains IDEs or plugins, utilizing Kotlin as the primary language. The delivery process involves close collaboration with external contributors and open-source users to ensure the highest stability of developer tools.

Desired Contractor Profile

  • Strong Kotlin skills or strong Java expertise with solid knowledge of Kotlin
  • Proficient understanding of asynchronous and concurrent programming (ideally with Kotlin Coroutines)
  • High agency and capability to deliver results in a dynamic, changing environment
  • Engineering pragmatism: reducing complexity while maintaining system extensibility
  • Hands-on experience utilizing LLMs daily, combined with the judgment to evaluate their efficacy
  • Fluency in English with strong communication skills tailored for a remote-first setup
  • High independence in driving technical features end-to-end

 

 

A few perks of being with us

Building tech community
Building tech community
Flexible hybrid work model
Flexible hybrid work model
Home office reimbursement
Home office reimbursement
Language lessons
Language lessons
MyBenefit points
MyBenefit points
Private healthcare
Private healthcare
Training Package
Training Package
Virtusity / in-house training
Virtusity / in-house training
Access to the above perks is optional and completely voluntary for B2B contractors

Apply now

Kotlin Engineer – (Senior/Staff)

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Current recruitment process: For the purpose of recruitment, I hereby give consent as per art. 6.1.a of the GDPR to processing of my personal data (other than that listed in art. 22 [1] § 1 Labour Code) by Virtus Lab Sp. z o. o. (as Co-Controller for a full list of joint controllers, see Privacy Policy) with its headquarters at Szlak 49 Street, 31-153 Cracow. At the same time I accept the Privacy Policy of the Data Controller. I acknowledge that my personal data will be kept for the duration of the recruitment process and as regards any potential claims, for the period of 36 months maximum, and that I have the right to access this data or have it rectified or deleted on demand. This consent can be withdrawn at any time, but this withdrawal does not make the previous processing illegal*.(Required)*

Current recruitment process: For the purpose of recruitment, I hereby give consent as per art. 6.1.a of the GDPR to processing of my personal data (other than that listed in art. 22 [1] § 1 Labour Code) by Virtus Lab Sp. z o. o. (as Co-Controller for a full list of joint controllers, see Privacy Policy) with its headquarters at Szlak 49 Street, 31-153 Cracow. At the same time I accept the Privacy Policy of the Data Controller. I acknowledge that my personal data will be kept for the duration of the recruitment process and as regards any potential claims, for the period of 36 months maximum, and that I have the right to access this data or have it rectified or deleted on demand. This consent can be withdrawn at any time, but this withdrawal does not make the previous processing illegal*.

(Required)
Future recruitment processes: I hereby give consent as per art. 6.1.a of the GDPR to the processing of my personal data by Virtus Lab Sp. z o. o. (as Co-Controller for a full list of joint controllers, see Privacy Policy) with its headquarters at Szlak 49 Street, 31-153 Cracow, in order to use this data in future recruitment processes. I hereby agree to possible storage of my personal data for this purpose in Virtus Lab’s database for a period of 36 months maximum. At the same time I accept the Privacy Policy of the Data Controller. I acknowledge that I have the right to access this data or have it rectified or deleted on demand. This consent can be withdrawn at any point, but this does not make the previous processing illegal*.

Future recruitment processes: I hereby give consent as per art. 6.1.a of the GDPR to the processing of my personal data by Virtus Lab Sp. z o. o. (as Co-Controller for a full list of joint controllers, see Privacy Policy) with its headquarters at Szlak 49 Street, 31-153 Cracow, in order to use this data in future recruitment processes. I hereby agree to possible storage of my personal data for this purpose in Virtus Lab’s database for a period of 36 months maximum. At the same time I accept the Privacy Policy of the Data Controller. I acknowledge that I have the right to access this data or have it rectified or deleted on demand. This consent can be withdrawn at any point, but this does not make the previous processing illegal*.

Karolina Buraś
Coordinated by
Karolina Buraś
Senior IT Talent Acquisition Specialist
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Kotlin Engineer – (Senior/Staff)
B2B140 - 185 PLN NET PER HOUR
LOCATION + Remote Poland: Kielce, Kraków, Wrocław
Apply now
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