1,813,263open jobs
104,194companies
275,393added this week
Browse all
Salary
≈ $45k – $80k per year (Estimated)
Location
Hybrid (Warsaw, Poland)
Seniority
Middle · 4+ years exp
Employment
Full-Time

Confirmed on the employer's own hiring board on Oct 17, 2026. First seen by Alion on Oct 12, 2026.

Overview
Company
Impact
Profile match
Viber is a messaging and voice-over-IP application owned by Japan's Rakuten that offers free encrypted chats, voice and video calls, group communities, channels and paid Viber Out calls to regular phone numbers. Founded in 2010, the app has hundreds of millions of users, especially in Eastern Europe, the Middle East and Southeast Asia, and runs development centres in Minsk and other cities. The company is headquartered in Luxembourg City, Luxembourg.

Description

Rakuten Viber is one of the most popular and downloaded apps in the world. Working with us provides a unique opportunity to influence hundreds of millions of our users and to be part of the journey that makes us a super-app. Our mission is to make people’s lives easier by enabling meaningful connections, from precious moments with family and friends, through managing business relationships to pursuing their passions.

We are a global team of engineers dedicated to creating the best tools to ensure safe, convenient, and fun communication for millions of users worldwide. Our culture is built on innovation, teamwork, and a commitment to excellence. We offer a unique opportunity to work with cutting-edge technologies, including microservices architecture, and influence the lives of millions of people.

As a Backend Developer at Viber, you will be involved in developing and maintaining high-traffic with over 1 billion messages a day and dozens of scalable services, ensuring the fast and reliable operation of our platform. Your tasks will include developing new features, optimizing performance, ensuring data security, and solving complex technical challenges within our microservices architecture, using a combination of Java, along with non-blocking and reactive approaches, Cloud services, and NoSQL databases.

Responsibilities

  • Planning, designing, developing and maintaining Java high-availability applications that can be high-volume and low-latency.
  • Define application objectives and functionality.
  • Ensure application designs conform with business goals.
  • Support continuous improvement, investigating alternatives and technologies, and presenting for architectural review.
  • Work in a highly motivated team, closely with Product and Architects teams on large mission-critical systems.

Requirements

  • At least 4 years of experience as a Backend Developer, with at least 2 years in Java.
  • Advanced knowledge of Java, from frameworks to libraries. Experience in Async and/or reactive Java frameworks (such as Vertx, Rxjava, Akka).
  • Advanced knowledge of unit testing frameworks and mocking.
  • Knowledge of cloud technologies.
  • Experience with using AI tools to increase productivity and quality.
  • Experience with large scale NoSQL database (such as Couchbase, MongoDB).
  • Experience with microservices development based on Docker and Kubernetes.
  • Experience with Agile methodology.
  • Striving for new knowledge and skill improvement.
  • Fluent in written and spoken English (interviews are in English).
  • Excellent oral and written communication skills.
  • Higher technical education.
  • Availability to work in a hybrid model - at least 3 days a week from the office.

Advantages

  • Knowledge of Javascript and web ui technologies.
  • Experience with other server-side languages such as Python.
  • Experience working with remote teams.
Free account
Stop reading job ads. Get the ones that fit.
One free account turns this page into a shortlist built around your stack, your level and your pay.
Match on every job. Stack, seniority, pay and location, scored against your profile.
1,813,263 open roles. Read straight off company career pages, refreshed every day.
Unlimited applications. Every one you send is tracked in one place, on-site or on a company board.
3 tailored CVs a month. Rewritten for the exact job you are applying to. Included free.
Create a free account Continue with Google
Free forever. No card. Under a minute.

Your match

How well do you fit this role?
Two answers are enough for a real match. No account needed.
Check my fit
Answers stay in this browser until you create an account.

Recommended for you based on this role

Backend
Similar stack
Same company
Warsaw
$38k – $77k per year • In office • Full-Time • Tokyo
JavaScript
TypeScript
Ruby
Node JS
Ruby
Ruby on Rails
Databases
MySQL
PostgreSQL
DynamoDB
Google BigQuery
Amazon Aurora
BigQuery
AI/ML
Copilot
Claude Code
Frontend
Vue.js
Nuxt.js
Next.js
React.js
DevOps
GCP
GitHub Actions
CI/CD
AWS
Apply
≈ $85k – $215k per year (Estimated) • Remote (likely Europe, UTC-6 – UTC+2 hours) • Full-Time • 7+ years exp
JavaScript
Ruby
C#
Scala
Databases
PostgreSQL
Redis
AI/ML
Cursor
Claude Code
AI Agents
OpenAI Codex
Agentic Workflows
Frontend
Redux
React.js
React Query
Storybook
XState
DevOps
CircleCI
AWS
Docker
Management
Slack
Apply
≈ $99k – $186k per year (Estimated) • Remote (United Kingdom) • Confidential • Full-Time • Bachelor's Degree • London
AI/ML
AI Agents
Apply
$156k – $253k per year • Equity • In office • Confidential • Full-Time • 12+ years exp • Bachelor's Degree • United States
C#
C#
.NET
Databases
PostgreSQL
Redis
AI/ML
Copilot
Cursor
Claude Code
AI Agents
DevOps
Rest API
GCP
Azure
CI/CD
AWS
Docker
Kubernetes
Amazon EKS
Google GKE
Azure AKS
SOAP
Cybersecurity
Threat Modeling
Active Directory
Management
Agile
Apply
≈ $139k – $296k per year (Estimated) • In office • Confidential • Full-Time • 6+ years exp • Bachelor's Degree • Petah Tikva
Go
Java
C#
C++
DevOps
Jenkins
AWS
Apply
≈ $36k – $63k per year (Estimated) • In office • Full-Time • 3+ years exp • Warsaw
DevOps
AWS
Linux
Management
Agile
Apply
≈ $25k – $62k per year (Estimated) • In office • 2+ years exp • Bachelor's Degree • Warsaw
SQL
Databases
MS SQL
Apache Kafka
Azure SQL Database
DevOps
Rest API
Azure
CI/CD
AWS
Docker
Kubernetes
Apply
≈ $47k – $91k per year (Estimated) • Hybrid • Warsaw
JavaScript
Java
Kotlin
TypeScript
SQL
Java
Spring Boot
Kotlin
Mockito
Databases
MySQL
PostgreSQL
Frontend
RxJS
Angular
NgRx
Mobile
JUnit
DevOps
Rest API
OpenShift
Azure DevOps
GitHub Actions
Azure
CI/CD
Jenkins
Git
Docker
Kubernetes
Cybersecurity
SonarQube
OWASP
Management
Agile
Apply
$59k – $109k per year (gross) • In office • Full-Time • 8+ years exp • Bachelor's Degree • Warsaw
Python
AI/ML
vLLM
Fine-tuning
Embeddings
Multimodal AI
Knowledge Distillation
Function Calling
AI Agents
LLM
RAG
Human-in-the-Loop
Context Engineering
Knowledge Graph
Agentic Workflows
Tool Use
Model Distillation
DevOps
GCP
CI/CD
Git
AWS
Kubernetes
Platform Engineering
FinOps
Apply
≈ $25k – $74k per year (Estimated) • Remote (Poland) • Full-Time • 2+ years exp • Warsaw
Python
JavaScript
TypeScript
SQL
Databases
PostgreSQL
AI/ML
Model Context Protocol
Frontend
Next.js
React.js
DevOps
Rest API
GitLab CI
Azure
CI/CD
Kubernetes
Azure AKS
Management
Agile
Apply
See all jobs
This is one of many
1,813,263 more open roles from verified company boards, updated every day.