Jobs Kotlin

N-iX is looking for a Lead/Senior Kotlin Engineer to join our team.

Our customer is a fintech company that provides flexible buy-now-pay-later solutions, enabling consumers to split purchases into transparent, interest-free, or interest-based payments. The customer's Platform team is responsible for managing critical services that are essential to the success and sustainability of the organization. 

In simple terms, the team handles transactional communication send-outs to customers via email, SMS, and push notifications. These services demand attention to detail, proactive maintenance, and swift response times to ensure seamless operations. 

The recent high-priority initiatives include re-architecture/platform modernization, high availability, and internationalization efforts; these are vital for our organization's growth and competitiveness in the market. These initiatives require dedicated expertise and resources to execute efficiently and effectively.

Main Responsibilities:

• Design and develop a robust and extensible Kotlin framework and platform.
• Own and deliver quarterly goals by leading engineers through ambiguity to solve open-ended problems while ensuring team support throughout delivery.
• Collaborate across the product development lifecycle with product management, design, and analytics to participate in ideation and articulate technical constraints.
• Drive decision-making and risk assessment by partnering on strategic technical choices that properly consider trade-offs and business impact.
• Proactively identify and resolve systemic issues across projects, processes, and technology, advocating for and leading the implementation of solutions.
• Ensure operational excellence and availability by creating and monitoring metrics, supporting "keep the lights on" efforts, and participating in an on-call rotation.
• Foster a culture of quality and ownership by setting high standards for code reviews and design, and advocating for best practices through technical writing and talks.

• Mentor engineering talent by providing actionable feedback, guidance, and leading by example to grow the team's capabilities.

   

Role Requirements:

• At least 5 years of proficiency in Kotlin with extensive experience designing, developing, and launching backend systems at scale
• Deep experience with distributed systems and high-availability architectures
• Experience in technical leadership in system design, with a proven ability to deliver significant features using elegant, simple, and extensible designs
• Strong infrastructure knowledge, including technologies such as AWS, MySQL/DynamoDB, and Kubernetes
• Proficiency in large-scale codebase management, utilizing a suite of tools and practices that ensure safe and efficient technical changes
• Experience in operational monitoring, including the use of metrics and tracing to maintain system health
• Excellent collaboration skills for effective partnership with global, cross-functional engineering teams
• Well spoken and written knowledge of the English language (C1)

Objective:

We are looking for Middle+ / Senior Backend Engineers to join an international e-commerce project. You will be responsible for designing, developing, and maintaining scalable backend systems that power high-traffic platforms.

You’ll collaborate closely with product managers, frontend engineers, and DevOps teams to deliver reliable and high-quality solutions in a modern cloud environment.
 

136h/month
Hybrid 60/40
Berlin
B2B
Long-Term
 

Responsibilities:

• Design, develop, and maintain backend systems using Java and Kotlin
• Translate business requirements into scalable technical solutions
• Ensure performance, scalability, and reliability of services
• Build and maintain RESTful APIs
• Follow best practices for code quality, testing, and deployment
• Conduct code reviews and mentor junior engineers
• Collaborate with DevOps on CI/CD, deployment, and monitoring
• Contribute to architectural decisions (microservices, cloud-native systems)

Qualifications:

• 4+ years of backend development experience
• Strong expertise in Java and Kotlin
• Solid understanding of OOP principles and design patterns
• Experience with REST APIs
• Microservices architecture experience
• Containerization (Docker, Kubernetes)
• Strong SQL & relational database knowledge
• Git proficiency
• Experience with CI/CD pipelines
• Experience with AWS or Google Cloud Platform
• Agile mindset, experience working with tools like JIRA
• Strong communication skills (English)
   

Recruitment process: 

• Pre-screen interview
• Tech screen 
• Client Tech Interview
• Business Interview

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

Technical Requirements

Backend Stack

• Strong experience with Spring Boot and Spring Framework
• Solid knowledge of Kotlin
• Experience building scalable and maintainable backend systems

API Development

• Strong understanding of RESTful API design principles
• Experience designing, developing, and maintaining REST APIs
• Experience generating and maintaining Swagger / OpenAPI documentation based on source code

Authentication & Authorization

• Experience with Google Cloud Platform (GCP) Identity Platform
• Experience working with multi-tenant architectures
• Solid understanding of OIDC (OpenID Connect) implementation
• Practical experience using JWT tokens as Bearer tokens
• Understanding of secure authentication and authorization best practices

Admin Dashboard Integration

• Understanding of frontend-backend integration
• Experience supporting applications built with:
  • ReactJS
  • Redux
  • TypeScript
• Ability to collaborate with frontend teams using a shared stack

Nice to Have

• Experience designing multi-tenant SaaS architectures
• Experience with cloud-native deployments on GCP
• Knowledge of API security best practices
• Experience with CI/CD pipelines

N-iX is looking for a Lead/Senior Java Engineer with Kotlin skills to join our team.

Our customer is a fintech company that provides flexible buy-now-pay-later solutions, enabling consumers to split purchases into transparent, interest-free, or interest-based payments. The customer's Platform team is responsible for managing critical services that are essential to the success and sustainability of the organisation. In simple terms, the team handles transactional communication send-outs to customers via email, SMS, and push notifications. These services demand attention to detail, proactive maintenance, and swift response times to ensure seamless operations. The recent high-priority initiatives include re-architecture/platform modernisation, high availability, and internationalisation efforts; these are vital for our organisation's growth and competitiveness in the market. These initiatives require dedicated expertise and resources to execute efficiently and effectively.
 

Main Responsibilities:

• Design and develop a robust and extensible Kotlin framework and platform.
• Own and deliver quarterly goals by leading engineers through ambiguity to solve open-ended problems while ensuring team support throughout delivery.
• Collaborate across the product development lifecycle with product management, design, and analytics to participate in ideation and articulate technical constraints.
• Drive decision-making and risk assessment by partnering on strategic technical choices that properly consider trade-offs and business impact.
• Proactively identify and resolve systemic issues across projects, processes, and technology, advocating for and leading the implementation of solutions.
• Ensure operational excellence and availability by creating and monitoring metrics, supporting "keep the lights on" efforts, and participating in an on-call rotation.
• Foster a culture of quality and ownership by setting high standards for code reviews and design, and advocating for best practices through technical writing and talks.
• Mentor engineering talent by providing actionable feedback, guidance, and leading by example to grow the team's capabilities.
   

Role Requirements:

• At least 5 years of proficiency in Kotlin with extensive experience designing, developing, and launching backend systems at scale
• Deep experience with distributed systems and high-availability architectures
• Experience in technical leadership in system design, with a proven ability to deliver significant features using elegant, simple, and extensible designs
• Strong infrastructure knowledge, including technologies such as AWS, MySQL/DynamoDB, and Kubernetes
• Proficiency in large-scale codebase management, utilizing a suite of tools and practices that ensure safe and efficient technical changes
• Experience in operational monitoring, including the use of metrics and tracing to maintain system health
• Excellent collaboration skills for effective partnership with global, cross-functional engineering teams
• Well spoken and written knowledge of the English language (C1)
   

We offer*:

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits

*not applicable for freelancers

N-iX is looking for a Middle Kotlin Engineer to join our team.

Our customer is a fintech company that provides flexible buy-now-pay-later solutions, enabling consumers to split purchases into transparent, interest-free, or interest-based payments. The customer's Platform team is responsible for managing critical services that are essential to the success and sustainability of the organisation. In simple terms, the team handles transactional communication send-outs to customers via email, SMS, and push notifications. These services demand attention to detail, proactive maintenance, and swift response times to ensure seamless operations. The recent high-priority initiatives include re-architecture/platform modernisation, high availability, and internationalisation efforts; these are vital for our organisation's growth and competitiveness in the market. These initiatives require dedicated expertise and resources to execute efficiently and effectively.
 

Main Responsibilities:

• Design and develop a robust and extensible Kotlin framework and platform.
• Own and deliver quarterly goals by leading engineers through ambiguity to solve open-ended problems while ensuring team support throughout delivery.
• Collaborate across the product development lifecycle with product management, design, and analytics to participate in ideation and articulate technical constraints.
• Drive decision-making and risk assessment by partnering on strategic technical choices that properly consider trade-offs and business impact.
• Proactively identify and resolve systemic issues across projects, processes, and technology, advocating for and leading the implementation of solutions.
• Ensure operational excellence and availability by creating and monitoring metrics, supporting "keep the lights on" efforts, and participating in an on-call rotation.
• Foster a culture of quality and ownership by setting high standards for code reviews and design, and advocating for best practices through technical writing and talks.
• Mentor engineering talent by providing actionable feedback, guidance, and leading by example to grow the team's capabilities.
   

Role Requirements:

• At least 3 years of proficiency in Kotlin with extensive experience designing, developing, and launching backend systems at scale
• Deep experience with distributed systems and high-availability architectures
• Experience in technical leadership in system design, with a proven ability to deliver significant features using elegant, simple, and extensible designs
• Strong infrastructure knowledge, including technologies such as AWS, MySQL/DynamoDB, and Kubernetes
• Proficiency in large-scale codebase management, utilizing a suite of tools and practices that ensure safe and efficient technical changes
• Experience in operational monitoring, including the use of metrics and tracing to maintain system health
• Excellent collaboration skills for effective partnership with global, cross-functional engineering teams
• Well spoken and written knowledge of the English language 
   

We offer*:

• Flexible working format - remote, office-based or flexible
• A competitive salary and good compensation package
• Personalized career growth
• Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more)
• Active tech communities with regular knowledge sharing
• Education reimbursement
• Memorable anniversary presents
• Corporate events and team buildings
• Other location-specific benefits

*not applicable for freelancers

Solid Software is currently seeking a skilled Mobile Developer (Android, Kotlin) with Odoo ERP experience to design, develop, and maintain Android applications that integrate with Odoo-based systems.
 

We offer a friendly, progressive, and dynamic work environment that combines modern technologies with inspiring projects.
 

Enjoy the flexibility of a full-time, long-term remote position. Join us in creating exceptional mobile experiences.
 

Apply now to become a vital part of our team!
 

What will you do?

• Collaborate with an experienced team to develop user-friendly, responsive, and high-performance Android applications using Kotlin;
• Integrate mobile applications with Odoo ERP APIs and backend services.
• Support specialized functionality for B2B marketplaces;
• Ensure application security, data integrity, and proper error handling;
• Participate in code reviews, testing, and release cycles;
• Solve complex technical challenges and implement effective solutions;
• Document technical decisions and app features.
• Stay updated on the latest trends, tools, and techniques, and share your newfound knowledge with the team.
   

Requirements:

• 2+ years of experience developing Android applications using Kotlin;
• Hands-on experience integrating mobile apps with Odoo ERP;
• Strong experience with REST APIs, authentication, and data synchronization;
• Experience building clean, scalable, and maintainable Android architecture;
• Solid understanding of Android UI/UX guidelines and best practices;
• Strong focus on code quality, maintainability, performance, and reliability;
• Understanding of application security, data integrity, and error handling best practices;
• Familiarity with Git or similar version control systems;
• Upper-intermediate English (B2): Able to lead meetings and draft reports.
   

Nice to have:

• Experience with Odoo custom modules or ERP-driven workflows;
• Familiarity with mobile app testing and deployment processes;
• Knowledge of CI/CD pipelines for Android applications.
   

Why Solid Software?

• We support Ukraine;
• A wonderful team of enthusiasts and like-minded people;
• Atmosphere of comfortable work & life balance;
• Flexible schedule and work-from-home jobs;
• Opportunity to work on sophisticated B2B solutions that challenge your architectural and coding skills;
• MacBook Pro and great tech;
• Decent compensation;
• Lack of bureaucracy;
• Compensation for professional events, English lessons, sports activities;
• Corporate parties and fun team-buildings;
• Anniversary presents;
• Accounting and juridical services.
   

Professional growth:

• Onboarding and mentorship program;
• Internal career path program from Developer to Architect that consists of knowledge areas for IT specialists, books, training sessions, and work activities;
• Corporate library with the best programming books (+ an ability to order a particular book if we don’t have it);
• Professional and constant feedback.
   

We truly value the unique talents and skills that each individual brings to our company. As we continue on our journey of growth, we eagerly anticipate the opportunity to welcome you into our team.
 

Talk to you soon!

Approximate start: 23.02.2026

Candidate profile: Senior Kotlin developer, 
5+ years of commercial experience; 
background in fintech/payment/banking; 
English B1+; 
EU-based.

Core skills: Kotlin, Spring Boot, REST, JSON, HTTP, microservices, Apache Camel/Kafka, SQL & NoSQL (PostgreSQL, MongoDB), Elasticsearch, Redis, Temporal, CI/CD (GitHub Actions/Jenkins/GitLab CI), AWS/GCP, Docker, Kubernetes, security (OAuth2/JWT/HTTPS), testing (JUnit, Mockito, Testcontainers), event‑driven architecture.

Location: EU

Approximate start: 23.02.2026

Candidate profile: Senior Kotlin developer, 
5+ years of commercial experience; 
background in fintech/payment/banking; 
English B1+; 
EU-based.

Core skills: Kotlin, Spring Boot, REST, JSON, HTTP, microservices, Apache Camel/Kafka, SQL & NoSQL (PostgreSQL, MongoDB), Elasticsearch, Redis, Temporal, CI/CD (GitHub Actions/Jenkins/GitLab CI), AWS/GCP, Docker, Kubernetes, security (OAuth2/JWT/HTTPS), testing (JUnit, Mockito, Testcontainers), event‑driven architecture.

Location: EU
Duration: 3 months

N.B.! Location: remote from Latvia/Lithuania; possible relocation (the company provides support).

JD:
In a partnership with a global consulting partner, we are looking for an experienced Kotlin Developer. The client is a Belgian telecommunication company.

What will you be doing?

You will play a key role in evolving our backend platform as we expand support beyond the Dutch market into Belgium, each with its own functional and regulatory needs.

In this role you will:

Design, build, and optimise backend systems primarily using Kotlin (≈50%) and Spring Boot.

Work extensively in our AWS environment (≈25%), leveraging services such as ECS, ECR, S3, SQS, SNS, AppSync, DocumentDB, DynamoDB, Lambda, API Gateway, Transfer Family, VPC, CloudWatch, CodePipeline, and Terraform.

Develop and maintain GraphQL APIs (≈15%), ensuring efficient and reliable data exchange between our services and clients.

Occasionally contribute to our TypeScript (≈10%) codebases, collaborating with frontend and platform teams when needed.

Continuously develop, test, and release new features in an Agile environment.

Embrace a "you build it, you run it" culture—taking full ownership of the software you deliver, including reliability, performance, and maintenance.

Help shape the architecture of our services and influence engineering standards within the team.

Contribute to a culture of continuous improvement—making systems more robust, scalable, secure, and observable.

Share knowledge, provide technical guidance, and help ensure the platform evolves in a future-proof way.

Must-haves:

Strong experience with Kotlin and Spring Boot.

Solid hands-on experience with AWS, ideally with several of the following:

ECS, ECR, Lambda, S3, DynamoDB, DocumentDB, SQS, SNS, AppSync, API Gateway, VPC, CloudWatch, CodePipeline, and Terraform.

Experience designing and developing RESTful and/or GraphQL APIs.

Familiarity with service-oriented or microservice architectures.

Comfort working in modern, automated CI/CD environments.

Strong focus on security, scalability, and operational excellence.

A proactive, self-driven mindset and the ability to work effectively in complex environments.

Nice to haves:

Experience building highly secure or high-availability systems.

Experience with Akamai or other edge / CDN technologies.

AWS certifications.

Experience with TypeScript in production systems.

Android Developer (Middle/Senior) — Next Era Solutions
Remote | Full-Time | Outstaff

About Next Era Solutions

Next Era Solutions is a mobile development team with 7+ years of experience delivering complex apps on time and within budget. We combine strong engineering practices, modern technology, and clear communication to help clients build reliable, user-friendly mobile products across different industries.

Engagement & Hiring Timeline

• Format: outstaff cooperation, full-time 40 hours/week, fully remote
• Fast 15-minute screening call (intro + expectations + quick fit check)
• Candidate confirmation typically takes about 2 weeks on average, but it can take up to 1 month depending on the client’s approval process

What you’ll do

• Build and maintain Android applications using Kotlin
• Deliver new features, refactor legacy code, and improve performance and stability
• Design and evolve architecture (MVVM/Clean Architecture; modularization when needed)
• Integrate with backend services via REST APIs and/or GraphQL
• Work with local storage, background tasks, and app lifecycle; ensure reliable releases
• Write tests (unit/UI), participate in code reviews, and improve team engineering practices
• Collaborate with product/design/backend; communicate with the client to clarify requirements and propose solutions
• For Senior level: take ownership of technical direction, mentor engineers, drive quality improvements

Typical stack (varies by project)

• Kotlin, Coroutines, Flow
• UI: Jetpack Compose and/or XML Views
• Architecture: MVVM, Clean Architecture, modularization
• Networking: Retrofit/OkHttp, REST, GraphQL
• Storage: Room, DataStore, SQLite
• Tools: Git, Android Studio, Gradle, CI/CD, Firebase, Figma

What we’re looking for

• 3+ years of commercial Android development experience (Middle/Senior level)
• Strong Kotlin skills; solid understanding of Android platform fundamentals
• Experience shipping and maintaining production apps on Google Play
• Good architecture knowledge, clean code mindset, and independence in delivery
• Hands-on experience with API integration (REST and/or GraphQL), async, error handling
• English level: B2 or higher for technical communication

Nice to have

• Jetpack Compose in production, performance optimization, profiling
• Push notifications, in-app purchases/subscriptions, deep links
• Experience with fintech/e-commerce or large-scale apps
• Client-facing experience and strong ownership

What we offer

• Full-time remote work 40 hours/week
• Long-term outstaff collaboration with stable workload
• Modern projects, clear processes, and a supportive engineering team
• Flexible location and schedule (results-focused)
• A major advantage: we support multiple payment options and can arrange the most convenient format for you (depending on your location and preferences)

How to apply

Apply and we’ll schedule a quick 15-minute screening call. If everything matches, we’ll guide you through the next steps and aim to confirm the candidate within about 2 weeks on average (up to 1 month depending on the client).

Radency у пошуках Senior Kotlin Engineer для роботи над платформою для менеджменту операційних процесів (Operations Management System) для виробництв.

Проєкт:

👉 OMS, яка дозволяє великим виробництвам досягати запланованих результатів, передбачати блокери та ризики і запобігати їх виникненню.

👉 Серед користувачів платформи масштабні аерокосмічні та оборонні підприємства.

👉 Техстек: Java, Kotlin, Websocket, Airflow, Azure VMs, Docker, GraphQL, PostgreSQL, Redis, RabbitMQ, ElasticSearch, InfluxDB, Gitlab.

Основні задачі позиції:

- Дизайн та побудова нових сервісів

- Розвиток поточної архітектури та вирішення питань, пов’язаних з навантаженням

- Моніторинг та покращення performance

- Написання unit та інтеграційних тестів

- Ухвалення складних технічних рішень разом з інженерною та продакт командою

Очікування від інженера:

- 6+ років досвіду розробки web додатків на Kotlin
- 7+ років досвіду роботи із SQL та даними

- Upper-Intermediate English

Що пропонує Radency:

✔️ Бюджети на навчання, здоровʼя та спорт - 750 $ на рік.

✔️ 20 днів тайм оффу, 10 державних вихідних та необмежені сік ліви.

✔️ Формат роботи remote-first.

🇺🇦 Активно підтримуємо ЗСУ - станом на лютий 2026 ми задонатили 24+ мільйонів гривень і не плануємо зупинятися.

🇺🇦 Не працюємо з російськими і білоруськими замовниками та інженерами.