Jobs Kotlin

About the Role:

We are looking for an experienced Backend Developer to join our team to build and scale modern applications. This role involves the full software development lifecycle, from architecture and API design to optimization, security, and continuous product improvement.

Responsibilities:

• Develop and maintain backend solutions using Kotlin.
• Participate in the development of web and Flutter applications.
• Design application architecture from scratch and create APIs.
• Ensure application security, performance, optimization, and scalability.
• Collaborate with Analysts, QA, and DevOps teams throughout the entire development lifecycle.

Requirements:

• 4+ years of commercial experience with JVM languages (Kotlin, Java, or Scala).
• Experience working with relational databases; experience with NoSQL is a plus.
• Hands-on experience building REST APIs and understanding asynchronous data processing.
• Knowledge of design patterns and microservices architecture principles.
• Basic DevOps skills.
• Experience with AI tools is a plus.
• English level sufficient to work with technical documentation.

We're looking for a strong Senior Full-Stack Developer to join an enterprise project for one of our long-term clients. We already have several developers successfully working on this project.

📌 Project

A web-based platform for German leasing companies that supports and automates their core business processes.

🚀 Senior Full-Stack Developer (Kotlin / Java / React)

📍 EU only (business trip to Germany for 3–4 days every 6 months)

🗣 English: C1

✅ Requirements

6+ years of software development experience

Strong Kotlin & Java

Strong React

Experience with PostgreSQL and/or MongoDB

CI/CD & automated testing

Experience with AI-assisted development

Strong software engineering and problem-solving skills

⭐ Nice to have

Node.js

💼 Responsibilities

Develop and enhance full-stack applications

Build scalable backend services with Kotlin & Java

Develop modern React features

Improve architecture and optimize existing modules

Collaborate with Product, QA, and DevOps teams

Participate in code reviews

We are looking for a Middle Kotlin developer who is not afraid of challenges and is ready to join our team of professionals working on an exciting product.
This is a freelance part-time position with an expected workload of from to 20 hours per week.

DARLY SOLUTIONS is an international IT company specializing in delivering innovative solutions across FinTech, MedTech, SaaS, etc.
With years of experience in web and mobile development, UI/UX design, Quality Assurance, AI, and machine learning, we pride ourselves on creating impactful products that drive success for our clients.Since 2018, we have successfully completed over 250 projects.
Examples of our work across various domains can be found on our website - https://www.darly.solutions/

About project:
The client is specializing in digital investment solutions and portfolio management, specifically targeting the 50+ generation. Current need is to create an Android application for investment portfolio management basing on the existing IOS app code (Swift). 

Requirements:
- Knowledge of the AI tools in the context of development, active AI usage in development;
- 2+ years of commercial experience with Kotlin development;
- Ability to write clean, maintainable, and testable code;
- Good problem-solving and debugging skills;
- English level - B2 (direct communication with client is present);
- Ability to work independently and collaborate effectively within a development team.

Responsibilities:
- Convert the Swift code into Kotlin, maintain, and improve Android application using AI agent (Claude);
- Identify, investigate, and resolve technical issues and application bugs;
- Ensure compatibility across supported Android devices and OS versions;
 -Maintain existing functionality and support application releases;
- Daily meetings participation and direct communication with the client.
 

Про роль:

Ми шукаємо досвідченого Backend Developer, який долучиться до розробки та масштабування сучасних застосунків. Роль передбачає участь у повному циклі розробки: від проєктування архітектури та API до оптимізації, безпеки й подальшого розвитку продуктів.

Основні обов'язки:

• Розробка та підтримка backend-рішень на Kotlin.
• Участь у розробці web - та Flutter-застосунків.
• Проєктування архітектури застосунків з нуля та дизайн API.
• Забезпечення безпеки, продуктивності, оптимізації та масштабованості застосунків.
• Співпраця з аналітиками, QA та DevOps-командами протягом усього циклу розробки.

Вимоги:

• 4+ роки комерційного досвіду розробки з використанням JVM-мов (Kotlin, Java або Scala).
• Досвід роботи з реляційними базами даних; досвід із NoSQL буде перевагою.
• Практичний досвід створення REST API та розуміння принципів асинхронної обробки даних.
• Знання патернів проєктування та принципів мікросервісної архітектури.
• Базові навички DevOps.
• Досвід роботи з AI-інструментами буде перевагою.
• Рівень англійської, достатній для роботи з технічною документацією.

PROJECT: We are building 4connection – a modern messenger with interest-based communities, serious dating/matching features, strong encryption, accessibility and youth protection. The Android client is built natively in Kotlin – no Flutter, no React Native. You will implement the UI from professional mockups, build the chat experience, integrate matching features and ensure the app is accessible and compliant with youth protection standards. The app connects to a Rust backend and uses Firebase for push notifications and real-time features.

REQUIREMENTS: 1+ years of experience in native Android development with Kotlin. Understanding of the Android lifecycle (Activities, Services, Background Processing). Experience with Firebase (Cloud Messaging, Realtime Database or Firestore). Basic knowledge of secure local storage (Android Keystore, EncryptedSharedPreferences). Experience with Git and project management tools (Redmine). Good English skills (reading and writing).

NICE TO HAVE: Experience with Jetpack Compose. Experience with accessibility features (TalkBack, content descriptions, scalable UI). Knowledge of youth protection or age verification concepts. Experience with real-time chat or messaging apps. Experience with matching/recommendation UIs.

RESPONSIBILITIES: Implementing the complete Android client based on UI/UX mockups. Building the chat interface, group features and matching/dating UI. Integrating Firebase for push notifications and real-time data. Implementing accessibility features to ensure the app is usable for everyone. Collaborating with the backend developer on API integration and testing. Owning the entire Android client – you know every corner of your codebase.

WE OFFER: Fully remote work. A small core team of 4 developers with direct communication. No Scrum theater, no daily standups – real collaboration instead. AI-assisted development with Claude. The Android client will be released as open source – your code will be publicly visible. This is both responsibility and opportunity. Fair compensation, long-term collaboration. Open-source tooling throughout (Nextcloud, Redmine, Git).

Tech Stack: Kotlin, Jetpack Compose, Firebase, Android Keystore, WebSocket, Git, Redmine, Nextcloud