{"id":2501598,"url":"https://alion.io/job/viber-backend-developer-java","title":"Backend Developer (Java)","company":{"id":2594,"name":"Viber","domain":"viber.com","url":"https://alion.io/company/rakuten-viber","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Comeet","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"middle","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Warsaw, Poland"],"countries":["PL"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":45000,"max_usd":80000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":91},"experience_years_min":4,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agile","optional":false},{"name":"Couchbase","optional":false},{"name":"Docker","optional":false},{"name":"JavaScript","optional":false},{"name":"Kubernetes","optional":false},{"name":"Python","optional":false},{"name":"RxJava","optional":false},{"name":"Vert.x","optional":false},{"name":"Java","optional":true}],"status":"live","first_seen_at":"2026-10-12T13:37:50Z","employer_posted_date":"2026-10-12","last_verified_at":"2026-10-17T22:04:08Z","board_verified":true,"closed_at":null,"days_open":5,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":5},"description":"Description\nRakuten 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.\nWe 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.\nAs 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.\nResponsibilities\nPlanning, designing, developing and maintaining Java high-availability applications that can be high-volume and low-latency.\nDefine application objectives and functionality.\nEnsure application designs conform with business goals.\nSupport continuous improvement, investigating alternatives and technologies, and presenting for architectural review.\nWork in a highly motivated team, closely with Product and Architects teams on large mission-critical systems.\nRequirements\nAt least 4 years of experience as a Backend Developer, with at least 2 years in Java.\nAdvanced knowledge of Java, from frameworks to libraries. Experience in Async and/or reactive Java frameworks (such as Vertx, Rxjava, Akka).\nAdvanced knowledge of unit testing frameworks and mocking.\nKnowledge of cloud technologies.\nExperience with using AI tools to increase productivity and quality.\nExperience with large scale NoSQL database (such as Couchbase, MongoDB).\nExperience with microservices development based on Docker and Kubernetes.\nExperience with Agile methodology.\nStriving for new knowledge and skill improvement.\nFluent in written and spoken English (interviews are in English).\nExcellent oral and written communication skills.\nHigher technical education.\nAvailability to work in a hybrid model - at least 3 days a week from the office. \nAdvantages\nKnowledge of Javascript and web ui technologies.\nExperience with other server-side languages such as Python.\nExperience working with remote teams.","description_format":"text","description_chars":2825,"description_truncated":false,"requirements":{"experience_years_min":4,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[{"language":"English","level":"All levels","optional":false}]},"benefits":[],"hiring_locations":[{"name":"Poland","iso":"PL","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Messaging Apps"],"lifecycle":[{"event":"open","at":"2026-10-14T06:10:50Z"}],"visa":[],"liveness":{"score":89,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.887,"p_room":1,"age_days":4,"expected_fill_days":30,"reasons":["seen:4","velocity","win:early"],"computed_at":"2026-10-17T05:46:00Z"},"pay":null,"html_url":"https://alion.io/job/viber-backend-developer-java","json_url":"https://alion.io/job/viber-backend-developer-java.json","meta":{"generated_at":"2026-10-18T00:04:23Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":126,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-19T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":2594},"rest":"https://alion.io/mcp/rest/get_company?id=2594"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fviber-backend-developer-java"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fviber-backend-developer-java"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fviber-backend-developer-java"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/viber-backend-developer-java\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fviber-backend-developer-java"}]}