{"id":3750250,"url":"https://alion.io/job/holisticon-senior-backend-software-engineer-javakotlin","title":"Senior Backend Software Engineer (Java/Kotlin)","company":{"id":1566,"name":"Holisticon","domain":"holisticon.pl","url":"https://alion.io/company/holisticon-connect","size_band":"51-200","is_staffing_agency":false,"employer_type":"services","is_intermediary":false,"listed_via":null,"ats_vendor":"Traffit","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":null,"work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"posting_text","remote_working_hours":null,"hiring_geo_confidence":"explicit","locations":[],"countries":[],"hiring_countries":["PL"],"hiring_countries_total":1,"salary":{"min":23500,"max":25000,"currency":"PLN","period":"month","gross":true,"usd_annual":76164},"salary_estimate":null,"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AWS","optional":false},{"name":"CI/CD","optional":false},{"name":"Docker","optional":false},{"name":"Java","optional":false},{"name":"Kotlin","optional":false},{"name":"Kubernetes","optional":false},{"name":"Rest API","optional":false},{"name":"SQL","optional":false}],"status":"live","first_seen_at":"2026-11-04T13:49:18Z","employer_posted_date":"2026-11-04","last_verified_at":"2026-11-10T04:05:14Z","board_verified":true,"closed_at":null,"days_open":5,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":5},"description":"Holisticon Connect is a division within NEXER GROUP - a custom software development company. We started in Poland in 2017 and are now a team of over 140 people. We have the opportunity to work with world-renowned brands from Scandinavia, the UK, and Western Europe. Our goal is to grow stronger, in competence rather than in numbers. If you like what we do, check out our offer, maybe we will have the pleasure of meeting you!\nWe are looking for a Senior Backend Software Engineer (Java/Kotlin) to join an international product company building a modern, cloud-native enterprise SaaS platform operating at global scale.\n You will join a mature engineering environment where scalable, distributed backend architectures, software reliability, strong system ownership, and long-term maintainability take priority over quick hacks. This role is built for an engineer who thrives on tackling complex architectural trade-offs, driving technical standards, and owning services throughout their entire lifecycle - from initial RFC/design through production telemetry.\nWe offer a choice of employment form: Employment Contract or B2B\nUoP: 23 500 - 25 000 PLN gross/month\nB2B: 170 - 180 PLN net/hour + VAT\nResponsibilities:\nArchitect, build, and maintain high-throughput, resilient backend microservices in Java or Kotlin.\n\nDrive technical decisions and system design, authoring design docs (RFCs) and evaluating architectural trade-offs (scalability, latency, data consistency).\n\nDesign and evolve robust APIs (REST, event contracts) and external integration layers for enterprise clients.\n\nOwn the full service lifecycle: from technical conception, through CI/CD automation and automated testing, to production deployment and live monitoring.\n\nContinuously optimize performance, concurrency, fault tolerance, and resource utilization across distributed components.\n\nFoster engineering excellence through insightful code reviews, architectural pairing, and setting testing/clean code standards.\n\nCollaborate cross-functionally with Product Managers, Platform/DevOps, and QA engineers to translate complex business requirements into clean, decoupled domain models.\n\nIdentify technical debt proactively and drive modernization initiatives across platform tooling and pipelines.\n\nYou might be the perfect match if you are/have:\n5+ yearsof professionalexperiencein backendsoftware development;\n\nStrongcommercialexperiencewith Java and/orKotlin;\n\nVerygoodunderstandingof object-orientedprogramming, software design principlesand cleancodepractices;\n\nExperiencedesigningand developing REST APIsand backendintegrations;\n\nExperiencebuildingand maintainingproduction-gradebackendapplications;\n\nGood understandingof distributedsystemsand modern backendarchitecture;\n\nPracticalexperiencewith relationaldatabasesand SQL;\n\nStrongknowledgeof version control, especiallyGit;\n\nExperiencewith automatedtestingand modern software engineering practices;\n\nAbilityto analysetechnicalproblems, evaluatedifferentapproachesand explainarchitecturaltrade-offs;\n\nA strongownershipmindsetand the abilityto workindependently;\n\nFluent Englishand Polishfor smooth collaboration in an international environment;\n\nLocated in Poland for at least 5 years.\n\nMoreover, we appreciate skills in these areas:\nExperiencewith Spring BootorotherJVM frameworks;\nExperiencewith event-drivenordistributedarchitectures;\nExperiencewith messagingorstreaming platforms;\nFamiliaritywith Docker and Kubernetes;\nExperiencewith cloudenvironmentssuchas AWS, AzureorGCP;\nExperiencewith CI/CD pipelines;\nKnowledge of observability, monitoring and productiontroubleshooting;\nExperiencewith performance optimizationand high-throughputbackendsystems;\nFamiliaritywith NoSQL, searchenginesordistributeddata stores;\nExperienceworkingin a SaaS orproduct-orientedenvironment;\nExperiencecontributingto technicalarchitectureorleadinglargerengineering initiatives.\n\nBy joining us, you gain the following:\nOpportunity to work on exciting, international projects in cutting-edge industries like Automotive, Biotech, IoT; \nPossibility to develop in cloud technologies;\nBecoming part of a team that believes that the next step to a promising future is to put your heart into it and make it happen; \n Respect for your private life so you don't have to work overtime or on weekends; \nTeam Events budget to socialize outside of work; \nCompany Events to celebrate smaller and bigger successes (Summer Party, Programmer's Day, and trips abroad - so far we've been in South Africa, Are, and Barcelona). \n\nPerks and benefits:\nFully remote work or in our office in Wrocław; \nBenefits such as Luxmed, Multisport, and life insurance in Nationale Nederlanden; \nAttractive referral system (9,5k for senior, 6k for mid, 2,5k for junior); \nPersonal Training Budget with additional paid hours; \nPassion Day - an extra day off for your hobby to spend as you please; \nFlexible working hours with no micro-management approach. Our core hours are 9-15, the rest of the working time is up to you; \nWe provide high-quality work equipment + 2 additional monitors and accessories.\nIf you apply for this position and match our expectations, then:\n1) You will be invited to an HR Screening with our IT Recruiter.\n2) You will meet with a client.\n3) Final decision and job offer.\nSubmit your application online in one easy step! Apply now!","description_format":"text","description_chars":5331,"description_truncated":false,"requirements":{"experience_years_min":5,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Company events","Flexible schedule","Life insurance"],"hiring_locations":[{"name":"Poland","iso":"PL","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Embedded Software & RTOS","IT Consulting & Digital Transformation","Custom Software Development","AI Consulting & Integration"],"lifecycle":[{"event":"open","at":"2026-11-04T14:58:46Z"}],"visa":[],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":4,"expected_fill_days":31,"reasons":["conf:3","velocity","win:early"],"computed_at":"2026-11-09T06:03:00Z"},"pay":{"stated_usd_annual":76164,"is_top_pay":false},"html_url":"https://alion.io/job/holisticon-senior-backend-software-engineer-javakotlin","json_url":"https://alion.io/job/holisticon-senior-backend-software-engineer-javakotlin.json","meta":{"generated_at":"2026-11-10T05:01:03Z","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":11742,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-11T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.1,"usd":0.01,"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":1566},"rest":"https://alion.io/mcp/rest/get_company?id=1566"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fholisticon-senior-backend-software-engineer-javakotlin"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":2,"usd":0.2},"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%2Fholisticon-senior-backend-software-engineer-javakotlin"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.1,"usd":0.01},"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%2Fholisticon-senior-backend-software-engineer-javakotlin"},{"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/holisticon-senior-backend-software-engineer-javakotlin\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fholisticon-senior-backend-software-engineer-javakotlin"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3750250}},{"tool":"search_jobs","arguments":{"company":"holisticon.pl","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3750250},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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