{"id":2657140,"url":"https://alion.io/job/plain-senior-product-engineer-ai","title":"Senior Product Engineer (AI)","company":{"id":1789275,"name":"Plain","domain":"plain.com","url":"https://alion.io/company/plain-com","size_band":"1-10","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"B","score":75,"open_postings":3,"ghost_share":0,"stale_share":1,"repost_share":0,"time_to_fill_p50_days":null,"computed_at":"2026-10-17T05:46:00Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"hybrid","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":{"min":90000,"max":140000,"currency":"GBP","period":"year","gross":null,"usd_annual":185591},"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Anthropic","optional":false},{"name":"Cursor","optional":false},{"name":"Discord","optional":false},{"name":"LLM","optional":false},{"name":"OpenAI","optional":false},{"name":"PostgreSQL","optional":false},{"name":"RAG","optional":false},{"name":"Slack","optional":false}],"status":"live","first_seen_at":"2025-11-10T10:16:44Z","employer_posted_date":"2025-11-10","last_verified_at":"2026-10-18T12:38:20Z","board_verified":true,"closed_at":null,"days_open":342,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":341},"description":"Plain is redefining customer support for the next generation of B2B companies. We’re building the fastest, most powerful platform to help companies move beyond reactive support and build true customer relationships.\nSome of the world’s most forward-thinking companies - like Cursor, Raycast, and Granola - trust Plain to unify all customer interactions, enable faster team collaboration, and supercharge their workflows with AI.\nB2B customer support is undergoing a seismic shift. AI is transforming the way companies engage with customers, shifting support from a siloed function to a company-wide effort across Slack, Discord, and any other channel you talk to customers in. The old way - slow, manual, and disconnected - no longer works.\nThis role is hybrid with 3 days a week in our London office.\nWhat you’ll do\nWe’re in a rare spot. Plain is already powering support for high-growth companies with a lightning-fast, deeply scalable platform. AI has been part of our DNA from the start. Now we’re doubling down to define how it shapes every layer of modern customer support.\nThis is where you come in.\nWe're looking for a customer obsessed Senior Product Engineer to help take our AI ambitions to the next level. You’ll build the Infrastructure that helps us build AI features quickly, safely and with confidence. You’ll own problems end to end, and play a key role in building a category-defining product.\nIn this role, you will:\nOwn and ship AI features such as our agents, assistants, insights and more - from concept to production.\n\nDesign and implement backend services for AI integrations and data pipeline.\n\nBuild robust APIs and abstractions for internal AI usage\n\nDrive system scalability: caching, optimization, processing patterns, etc\n\nContribute and drive the evolution of the infrastructure for AI including architecture, evaluation and iteration pipelines.\n\nSolve complex AI challenges around AI accuracy, reliability, and quality - using rigorous quantitive approaches.\n\nAdvocate for our work externally - writing, speaking, and engaging with the broader AI community.\n\nThis is a great fit if you…\nAre an experienced backend engineer who’s shipped AI products in the OpenAI & Anthropic era - especially text and data-heavy AI applications.\n\nHave hands-on experience with LLM orchestration and LLM API optimization (costs, latency, etc)\n\nAre familiar with RAG architectures and technologies\n\nHave AI observability experience. AI isn’t just about shipping features that sound great - it’s about knowing, conclusively, if they’re making things better.\n\nHave a clear perspective on what makes a great AI product. We want to apply AI with precision, nuance, and real impact - not as a gimmick.\n\nAre product minded and customer focused in how you build software.\n\nMeasure your success by user impact, not just technical elegance.\n\nAre self-driven, impact-focused, and thrive in a fast-moving, high-ownership environment.\n\nBonus: you have experience with agent frameworks and design.\n\nThis won’t be the right role if you…\nHave primarily academic or research ML/AI experience. This role’s looking for someone with Applied AI experience.\n\nThink AI for support is just chatbots and deflection. B2B support is complex - we want AI through the platform, not just automating conversations.\n\nStruggle with ambiguity. We’re an early-stage startup. Things change quickly, and often, knowing what to work on is as important as the work itself.\n\nPrioritize working with the latest tech for its own sake. We choose tools that make us productive - not what’s trendy. (Postgres is great.)\n\nAre looking for a management role. This is a hands-on individual contributor position.\n\nWant the perks of a big company. We offer competitive compensation for our stage, but we’re a startup - this is a different kind of opportunity.","description_format":"text","description_chars":3822,"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":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Artificial Intelligence","AI Agents"],"lifecycle":[{"event":"open","at":"2026-10-15T23:19:02Z"}],"visa":[{"country":"GB","licensed_sponsor":true,"evidence":"Licensed UK visa sponsor (Skilled Worker)","filings_12m":null,"filings_prev_12m":null,"green_card_filings_12m":null,"median_offered_wage_usd":null,"route":"Skilled Worker","cap_exempt":false,"checked_at":"2026-10-17T06:21:15+00:00","sources":["UK Home Office: register of licensed sponsors (workers)"],"filings_for_role_12m":0}],"liveness":{"score":6,"band":"cold","label":"Long shot","p_open":1,"p_active":0.209,"p_room":0.28,"age_days":340,"expected_fill_days":24,"reasons":["conf:1","urgency","win:tail","crowd:"],"computed_at":"2026-10-17T05:46:00Z"},"pay":{"stated_usd_annual":185591,"is_top_pay":true},"html_url":"https://alion.io/job/plain-senior-product-engineer-ai","json_url":"https://alion.io/job/plain-senior-product-engineer-ai.json","meta":{"generated_at":"2026-10-18T15:51:26Z","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":21810,"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":1789275},"rest":"https://alion.io/mcp/rest/get_company?id=1789275"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fplain-senior-product-engineer-ai"},{"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%2Fplain-senior-product-engineer-ai"},{"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%2Fplain-senior-product-engineer-ai"},{"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/plain-senior-product-engineer-ai\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fplain-senior-product-engineer-ai"}]}