{"id":28722,"url":"https://alion.io/job/welltech-senior-fullstack-engineer-cross-platform","title":"Senior Fullstack Engineer, Cross-platform","company":{"id":7758,"name":"Welltech","domain":"welltech.com","url":"https://alion.io/company/welltech","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":null},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"board_field","remote_working_hours":null,"hiring_geo_confidence":"inferred","locations":[],"countries":[],"hiring_countries":["BG","HU","RO","AM","EE","LV","LT"],"hiring_countries_total":7,"salary":null,"salary_estimate":{"min_usd":47000,"max_usd":88000,"period":"year","method":"role_seniority_country_cell","sample_n":8},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"A/B Testing","optional":false},{"name":"Agentic Workflows","optional":false},{"name":"AI Agents","optional":false},{"name":"CI/CD","optional":false},{"name":"React Native","optional":false},{"name":"Trunk-Based Development","optional":false},{"name":"TypeScript","optional":false},{"name":"Exoplayer","optional":true},{"name":"JavaScript","optional":true},{"name":"Node JS","optional":true},{"name":"OWASP","optional":true},{"name":"React.js","optional":true}],"status":"live","first_seen_at":"2026-06-15T15:20:23Z","employer_posted_date":"2026-06-15","last_verified_at":"2026-10-16T11:55:21Z","board_verified":true,"closed_at":null,"days_open":123,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":122},"description":"Who Are We?\nWelltech is a global wellness technology company with Ukrainian roots. Our mission is to build and scale wellness apps globally through state-of-the-art, tech-driven performance marketing.\nWe are one of the most established players in the wellness app space, and we are accelerating. Over 25.5 million people across the world use our apps - Muscle Booster, Yoga-Go, and WalkFit - to build healthier habits, move more, and feel better every day. Every subscription represents a real person making a real change in their life, and we take that seriously.\nWith 500+ people across hubs in Cyprus, Ukraine, Poland, Spain, and the UK, we combine the scale of a market leader and the drive of a team that's just getting started.\nThe Product Engineer Mindset\nWe don’t hire people to implement specs. We hire people who can spot the right problem to solve, talk directly to product, design, data, and users to sharpen it, and ship the thinnest version that proves the bet, then iterate. If this is you, you probably:\nMeasure your work in outcomes, not output. A feature isn’t done when it merges; it’s done when the metric moves, or you’ve learned it won’t, and killed it.\n\nGo to the source. You don’t wait for a perfect PRD. You sit with PMs, designers, marketers, and data, and sometimes users directly, to understand what’s actually being asked.\n\nOwn things end-to-end. From the first conversation about a problem through architecture, code, rollout, monitoring, and the follow-up experiment. You don’t hand work off at a boundary.\n\nHave a strong bias to ship. Prototypes, A/B tests, feature flags, kill switches. You’d rather get something in front of users this week than a perfect plan in two months.\n\nTreat AI as leverage, not a novelty. You use agentic workflows to compress the loop between idea and learning, for yourself and the team.\n\nWhat You’ll Own\nThis is an ownership role, not a feature factory seat. You’ll be on the hook for outcomes across the stack, not just the code in your area:\nA cross-platform foundation, end to end. Mobile, web, BFF, and infrastructure layers, built and evolved with an AI-first, agentic development approach, and held to outcomes you helped define.\n\nScalable foundations for health & fitness apps. React Native and modern web technologies, designed so product teams can ship and experiment faster without rederiving the basics each time.\n\nThe discovery loop with stakeholders. Working directly with product, design, marketing, and data to translate business bets into running experiments, not just tickets in a backlog.\n\nAI-agentic workflows across the SDLC. You’ll continuously improve how the team uses AI to raise productivity, code quality, and delivery speed, and prove the impact.\n\nShared platform capabilities. Internal tooling, CI/CD pipelines, and AI-assisted workflows that make every engineer at Welltech faster and the product better.\n\nNative mobile and media experiences. Video playback, streaming, and HLS, owned from native integration through user-perceived quality.\n\nModular, reusable systems. Backend-driven UI, white-label capabilities, and the architectural choices that let one team’s work compound for the next.\n\nReliable integrations. Between frontend clients, BFF services, and platform infrastructure, with you on the hook for the health of the seams.\n\nThe engineering culture. Architecture discussions, code reviews or pairing when working on trunk based development workflows, documentation, and continuous improvement, leading by what you ship and how you ship it.\n\nWhat We’re Looking For\nKey responsibilities:\nBuild and evolve a cross-platform ecosystem covering mobile, web, BFF, and infrastructure layers using an AI-first, agentic development approach\n\nDesign scalable foundations for health & fitness applications powered by React Native and modern web technologies\n\nWork directly with product, design, and marketing stakeholders to rapidly translate business needs into scalable technical solutions and experiments\n\nDevelop and continuously improve AI-agentic workflows across the full development lifecycle to increase team productivity, code quality, and delivery speed\n\nDevelop shared platform capabilities, internal tooling, CI/CD pipelines, and AI-assisted workflows that improve development speed and product quality\n\nWork on native mobile integrations and advanced media experiences, including video playback, streaming, and HLS-based solutions\n\nContribute to modular architectures, reusable systems, backend-driven UI solutions, and white-label application capabilities\n\nBuild reliable and scalable integrations between frontend clients, BFF services, and platform infrastructure\n\nParticipate in architecture discussions, code reviews, documentation, and continuous improvement of engineering workflows\n\nRequired skills:\nStrong commercial experience with React Native and modern TypeScript-based application development\n\nSolid understanding of full-stack architecture including mobile, web, BFF, and cloud/infrastructure layers\n\nExperience building scalable cross-platform systems and shared application foundations\n\nDeep understanding of software architecture, modular systems, scalability, and performance optimization\n\nExperience working with CI/CD pipelines, automation tooling, and modern developer workflows\n\nStrong engineering mindset focused on maintainability, reliability, testability, and fast iteration\n\nComfortable working in AI-assisted or agentic development environments and adopting new AI-driven workflows quickly\n\nExperience with backend-driven UI architectures\n\nNice to have:\nExperience building white-label mobile applications or multi-brand ecosystems\n\nExperience designing and implementing BFF (Backend for Frontend) services\n\nHands-on backend development experience with TypeScript (Node.js)\n\nExperience building internal developer platforms, shared tooling, or scalable platform capabilities\n\nFamiliarity with OWASP mobile security best practices\n\nExperience with engineering methodologies focused on rapid iteration and high developer productivity (Trunk Based Development, CI/CD mindset, TDD, BDD, XP, etc.)\n\nStrong experience with native mobile integrations and media/video playback technologies\n\nHands-on experience with HLS streaming and native video player integrations on iOS and Android (AVPlayer, ExoPlayer, Chromecast, AirPlay)\n\nCandidate journey: ⭕ Recruiter call --> ⭕ Meet a Hiring Manager--> ⭕ Skills assessment-->Live coding\nCheck out some of our products\nMuscle Booster - https://musclebooster.fitness/\nYoga-Go - https://yoga-go.io/\nWalkFit - http://walkfit.pro","description_format":"text","description_chars":6593,"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":"Bulgaria","iso":"BG","kind":"country"},{"name":"Hungary","iso":"HU","kind":"country"},{"name":"Romania","iso":"RO","kind":"country"},{"name":"Armenia","iso":"AM","kind":"country"},{"name":"Estonia","iso":"EE","kind":"country"},{"name":"Latvia","iso":"LV","kind":"country"},{"name":"Lithuania","iso":"LT","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Fitness","Consumer Health Apps"],"lifecycle":[{"event":"open","at":"2026-06-15T15:20:23Z"}],"visa":[],"liveness":{"score":13,"band":"cold","label":"Long shot","p_open":1,"p_active":0.482,"p_room":0.28,"age_days":122,"expected_fill_days":35,"reasons":["conf:2","win:tail","crowd:"],"computed_at":"2026-10-16T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/welltech-senior-fullstack-engineer-cross-platform","json_url":"https://alion.io/job/welltech-senior-fullstack-engineer-cross-platform.json","meta":{"generated_at":"2026-10-16T15:30:23Z","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":15304,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-17T00:00:00Z"}},"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":7758},"rest":"https://alion.io/mcp/rest/get_company?id=7758"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fwelltech-senior-fullstack-engineer-cross-platform"},{"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%2Fwelltech-senior-fullstack-engineer-cross-platform"},{"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%2Fwelltech-senior-fullstack-engineer-cross-platform"},{"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/welltech-senior-fullstack-engineer-cross-platform\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fwelltech-senior-fullstack-engineer-cross-platform"}]}