{"id":68421,"url":"https://alion.io/job/hash-frontend-engineer","title":"Frontend Engineer","company":{"id":26345,"name":"HASH","domain":"hash.ai","url":"https://alion.io/company/hash","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Gem","truth_index":{"grade":"A","score":95,"open_postings":14,"ghost_share":0,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":192,"computed_at":"2026-10-16T05:45:00Z"}},"role":"Frontend","role_family":"Frontend","seniority":null,"employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Knowledge Graph","optional":false},{"name":"Multimodal AI","optional":false},{"name":"React.js","optional":false},{"name":"TypeScript","optional":false},{"name":"BPMN","optional":true},{"name":"JavaScript","optional":true},{"name":"Trello","optional":true},{"name":"UML","optional":true},{"name":"WebAssembly","optional":true}],"status":"live","first_seen_at":"2026-01-28T20:17:32Z","employer_posted_date":"2026-05-01","last_verified_at":"2026-10-17T03:58:50Z","board_verified":true,"closed_at":null,"days_open":261,"trust":{"level":"ok","repost_count":0,"flags":[],"days_open":261},"description":"About HASH\nHASH's open-source platform helps firms integrate both structured and unstructured information into knowledge graphs that support simulating, optimizing and automating processes. Our mission is to solve information failure, and help everybody make the right decisions. To that end, we're unapologetically excited. Actions speak louder than words, and we measure performance by output. We prioritize speed, and measure product delivery timelines in hours and days, not months and years. We value high-energy, high-expectations people who do what they say and say what they mean. We're committed to building a high-commitment, high-trust environment, and believe that the best teams are most productive together, in-person. We're therefore currently hiring exclusively in both London (UK) and Berlin (Germany) to join the firm.\nAbout the role\nWe’re a fast-growing deep-tech company crafting web-based tools that help people model, understand, and optimize real-world systems and processes using AI. From interactive process-model editors to real-time simulations, we turn complex, non-textual data into intuitive, responsive, accessible web apps designed to be used by non-technical domain experts at research labs, startups and enterprises worldwide.\nAs a senior Frontend Engineer you’ll own end-to-end delivery of novel world modeling and AI native interface components, helping shape our frontend architecture, as part of an Advanced Research + Invention Agency funded project building systems for delivering “Safeguarded AI”. You’ll collaborate with technical product management, UX researchers and AI engineers from top labs, as well as our own developers and leadership, to push the boundaries of what a browser can do - whether that’s a drag-and-drop model builder, timeline-based simulator, or multimodal feedback interface.\nWhat you'll work on\nDay to day, you'll:\nDesign, build, and ship production-ready React/TypeScript components and app-wide features for complex data-driven UIs\nWork with mathematical experts to convert world-modeling theory formalizations into software requirements, and writing tests which ensure implementation correctness\nConvert novel UX/UI designs - for new world modeling and AI-interaction features - into performant, responsive and accessible experiences that work across devices\nEstablish project-wide standards for code quality (e.g. via linting), review and testing, and provide feedback on the work of other frontend engineers\nProfile and optimize rendering performance for complex interactions and visualisations\nTell the story of best practices and lessons learned in developing and testing novel, complex world-modeling interfaces, e.g. via blog posts and workshops\nPartner with backend/infra teams to identify and manage interdependencies, and to help define robust APIs that support excellent, feature-rich frontend performance\nStay on top of emerging browser capabilities and drive adoption of the ones that matter\nRequirements\nMust have\nExpertise with React, TypeScript, modern HTML & CSS\nProven track record architecting and delivering rich web apps that involve complex user interactions\nRigorous approach to documenting and versioning components for external audiences\nExperience profiling and debugging performance in devtools\nComfortable taking a visible technical leadership role, mediating discussions around standards and implementation approaches, and taking accountability for the delivery of features on time and to spec\nExcellent written & verbal communication in English and comfort working async\nNice to have\nFamiliarity with process/model-oriented UIs: BPMN, UML, systems-dynamics models, graphs, etc.\nUnderstanding of WCAG 2.2 and pragmatic accessibility techniques (ARIA, focus management, keyboard UX)\nPublic record of maintaining a well-documented, semantically versioned library (ideally in an open-source context)\nExperience with CRDTs or other real-time collaboration solutions\nHands-on experience with WebAssembly pipelines\nCanvas/WebGL experience for high-performance rendering\nBenefits\nWe offer leading equity-weighted total compensation, including competitive salaries and tax-advantaged options. We also offer:\nEmployer pension contributions\nAt least 30 days holiday annually\nQuarterly in-person team retreats around the world\nHASH's founders have previously founded and sold companies like Stack Overflow and Trello for hundreds of millions and billions of dollars.\nThis role pays £70,000-£120,000 base/bonus + meaningful equity.","description_format":"text","description_chars":4517,"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":[{"language":"English","level":"Upper-Intermediate (B2)","optional":false}]},"benefits":["Equity"],"hiring_locations":[{"name":"Germany","iso":"DE","kind":"country"},{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Data Integration & ETL Tools","Knowledge Graphs","Intranet & Knowledge Management"],"lifecycle":[{"event":"open","at":"2026-01-28T20:17:32Z"}],"visa":[],"liveness":{"score":23,"band":"cold","label":"Long shot","p_open":1,"p_active":0.514,"p_room":0.44,"age_days":260,"expected_fill_days":192,"reasons":["conf:3","win:tail","crowd:"],"computed_at":"2026-10-16T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/hash-frontend-engineer","json_url":"https://alion.io/job/hash-frontend-engineer.json","meta":{"generated_at":"2026-10-17T05:37:43Z","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":7580,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-18T00:00:00Z"}},"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":26345},"rest":"https://alion.io/mcp/rest/get_company?id=26345"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fhash-frontend-engineer"},{"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%2Fhash-frontend-engineer"},{"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%2Fhash-frontend-engineer"},{"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/hash-frontend-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fhash-frontend-engineer"}]}