{"id":4010544,"url":"https://alion.io/job/tech-stack-senior-full-stack-engineer-react-java","title":"Senior Full-Stack Engineer (React + Java)","company":{"id":454527,"name":"Tech Stack","domain":"tech-stack.com","url":"https://alion.io/company/tech-stack-2","size_band":"11-50","is_staffing_agency":true,"employer_type":"agency","is_intermediary":false,"listed_via":null,"ats_vendor":null,"truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"posting_text","remote_working_hours":{"label":"CET","utc_offset_min":1,"utc_offset_max":1},"hiring_geo_confidence":"inferred","locations":["Ukraine"],"countries":["UA"],"hiring_countries":["PL"],"hiring_countries_total":1,"salary":null,"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"CI/CD","optional":false},{"name":"Flyway","optional":false},{"name":"Hibernate","optional":false},{"name":"JavaScript","optional":false},{"name":"MariaDB","optional":false},{"name":"React.js","optional":false},{"name":"TypeScript","optional":false},{"name":"Amazon S3","optional":true},{"name":"AWS","optional":true},{"name":"Confluence","optional":true},{"name":"Cucumber","optional":true},{"name":"Docker","optional":true},{"name":"Figma","optional":true},{"name":"Java","optional":true},{"name":"Jira","optional":true},{"name":"JUnit","optional":true},{"name":"Linux","optional":true},{"name":"Miro","optional":true},{"name":"PostgreSQL","optional":true},{"name":"Redis","optional":true},{"name":"Slack","optional":true}],"status":"live","first_seen_at":"2026-11-10T09:41:30Z","employer_posted_date":null,"last_verified_at":"2026-11-10T09:41:30Z","board_verified":false,"closed_at":null,"days_open":0,"trust":{"level":"not_scored","repost_count":null,"flags":[],"days_open":0},"description":"About the project:\n\nWe’re looking for a Senior Full-Stack Developer (frontend focus) to join a project for a Dutch bookkeeping platform that is modernizing its accounting core: moving from legacy single-entry logic to a database-backed double-entry model, with better ledger-code management and reconciliation. The live platform stays fully operational, so all changes are delivered safely within the existing architecture, together with the client’s engineering team.\n\nThis is a frontend-focused role: React and production MobX experience are the core, while Java/Spring knowledge helps you deliver features end to end. Full-time, approximately 6 months.\n\nStart & timeline:\n\nWe’re hiring in advance. The project is currently in Phase 2, and the role starts with Phase 3, expected in early January 2027 (exact date TBC). We’ll keep you updated throughout the hiring process.\n\nYour team:\n\nYou’ll join an established Techstack team and work closely with the client’s internal engineers. The team includes a Project Manager, Lead Software Engineer, QA Engineer, Senior Full-Stack Developer (this position), 2 Back-End Developers, plus the client’s Solution Architect and CTO. We work through daily stand-ups, sprint reports, regular code reviews, and close communication with the client’s developers.\n\nCulture:\n\nWe uphold high standards in the tech industry and continuously evolve to meet them. Every team member can influence the product, the company, internal processes, and their own professional growth. We also regularly organize team-building activities to keep a friendly atmosphere and simply enjoy time together.\n\nTechnical stack:\n\nFrontend: React, MobX, TypeScript, JavaScript\n\nBackend: Java, Spring, Hibernate, JPA, Redis\n\nDatabase: MariaDB, PostgreSQL, Flyway\n\nTesting: API/Cucumber, JUnit 5, WireMock, frontend/browser testing\n\nCI/CD & hosting: SonarCloud, CI pipelines, Docker, Linux, WAR deployment, AWS S3\n\nTools: Jira, Confluence, Miro, Slack, Figma\n\nPractices: feature flags, code reviews, small PRs, regular releases\n\nYour responsibilities:\n\nDevelop and maintain features in existing React/MobX applications used by clients and bookkeepers\n\nBuild administrative and configuration interfaces for ledger management and accounting workflows\n\nImplement searchable lists, forms with validation, role-based permissions, and reconciliation views\n\nIntegrate frontend functionality with existing Java/Spring back-end APIs\n\nSupport back-end development when needed for end-to-end delivery\n\nMake sure changes do not disrupt existing functionality in the live production platform\n\nWrite and maintain frontend and browser-level automated tests\n\nDeliver changes through focused pull requests, feature flags, and regular releases\n\nCollaborate with the Tech Lead, back-end developers, QA, PM, and the client’s engineering team\n\nParticipate in code reviews, daily stand-ups, demos, and acceptance testing\n\nIt’s about you:\n\nStrong commercial experience with React, TypeScript, and JavaScript\n\nHands-on production experience with MobX\n\nWorking knowledge of Java and Spring for end-to-end feature development\n\nExperience building admin/configuration interfaces, searchable lists, forms with validation, and role-based access\n\nExperience working with large existing codebases and maintaining backward compatibility\n\nExperience with feature flags, CI/CD, and small, focused pull requests\n\nExperience writing frontend and browser-level tests\n\nAbility to follow established architecture guidelines and collaborate through the client’s code reviews\n\nGood spoken and written English for daily communication with the client; Dutch is not required\n\nTime zone: Europe/Kyiv or compatible with CET/CEST working hours\n\nWould be a plus:\n\nExperience in accounting, bookkeeping, or FinTech\n\nExperience with MariaDB, Hibernate, and Flyway\n\nExperience working with European clients\n\nWhat we can offer you:\n\nFull-time engagement (40h/week) on a product with a complex, high-integrity domain\n\nDirect communication with all stakeholders, including the client’s engineering team\n\nBroad opportunities for professional and career growth: challenges, meetups, hackathons, professional communities, and more\n\nHorizontal connections and no micromanagement: all team members are accessible to each other for any questions\n\nHubs in Kharkiv, Kyiv, Lviv, and Wrocław (Poland), or everything necessary for remote work\n\nUp to 50% compensation for educational courses and conferences\n\nFree English and business English courses\n\n20 days off and 7 sick days\n\nLegal and accounting support\n\nAppreciation gifts for significant events and occasions\n\nHow to join Techstack:\n\nPre-screening with a Talent Acquisition Specialist\n\nEnglish check\n\nTechnical interview and evaluation with Techstack engineers\n\nCandidate profile submission to the client\n\nTechnical interview with the client’s engineering representatives (if requested)","description_format":"text","description_chars":4884,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[{"name":"Poland","iso":"PL","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":[],"lifecycle":[{"event":"open","at":"2026-11-10T09:41:30Z"}],"visa":[],"liveness":{"score":52,"band":"ok","label":"Likely open","p_open":1,"p_active":0.516,"p_room":1,"age_days":0,"expected_fill_days":7,"reasons":["seen:0","agency","win:early"],"computed_at":"2026-11-10T11:22:30Z"},"pay":null,"html_url":"https://alion.io/job/tech-stack-senior-full-stack-engineer-react-java","json_url":"https://alion.io/job/tech-stack-senior-full-stack-engineer-react-java.json","meta":{"generated_at":"2026-11-10T11:22:30Z","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":26392,"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":454527},"rest":"https://alion.io/mcp/rest/get_company?id=454527"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Ftech-stack-senior-full-stack-engineer-react-java"},{"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%2Ftech-stack-senior-full-stack-engineer-react-java"},{"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%2Ftech-stack-senior-full-stack-engineer-react-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/tech-stack-senior-full-stack-engineer-react-java\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Ftech-stack-senior-full-stack-engineer-react-java"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":4010544}},{"tool":"search_jobs","arguments":{"company":"tech-stack.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":4010544},"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. Docs: https://alion.io/developers"}}