{"id":3723670,"url":"https://alion.io/job/roblox-corporation-principal-machine-learning-engineer-matchmaking","title":"Principal Machine Learning Engineer - Matchmaking","company":{"id":246,"name":"Roblox Corporation","domain":"roblox.com","url":"https://alion.io/company/roblox","size_band":"5000+","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"B","score":75,"open_postings":45,"ghost_share":0,"stale_share":0.8,"repost_share":0.022,"time_to_fill_p50_days":66,"computed_at":"2026-11-09T06:03:00Z"}},"role":"AI/ML","role_family":"AI/ML","seniority":"lead","employment_type":null,"work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["San Mateo, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":295250,"max":345040,"currency":"USD","period":"year","gross":null,"usd_annual":345040},"salary_estimate":null,"experience_years_min":8,"visa_sponsorship":true,"relocation_package":false,"has_equity":true,"technologies":[{"name":"Machine Learning","optional":false}],"status":"live","first_seen_at":"2026-11-03T23:24:16Z","employer_posted_date":"2026-11-03","last_verified_at":"2026-11-10T04:31:35Z","board_verified":true,"closed_at":null,"days_open":6,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":6},"description":"Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences- all created by our global community of developers and creators. \nAt Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. \nA career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone.\nMatchmaking is a critical stage downstream of Discovery and Search. Once a player chooses a game to play, matchmaking assigns them to a server for that game. That decision shapes who they play with, the network latency they experience, and the quality of their session. By matching players to servers that fit their needs and each developer’s game, matchmaking helps turn discovery into satisfying play, repeat visits, and long-term engagement, making it a direct lever for Roblox’s growth.\nAs a Principal ML Engineer on Matchmaking, you’ll own the technical vision and execution for the models, objective functions, and algorithms that make those decisions. You’ll combine predictions of high-value player actions with optimization of player and developer utility and system efficiency, serving millions of players across hundreds of thousands of servers in global datacenters.\nYou Will:\nOwn the technical direction and ML strategy for matchmaking, connecting the Discovery and Search journey to server placements that improve player experience, developer success, and Roblox growth.\nDefine and evolve the matchmaking objective function to balance player and developer utility with system efficiency. Make tradeoffs among co-player compatibility, network and join latency, engagement, retention, server utilization, and compute cost explicit and measurable.\nBuild models that predict high-value actions and longer-term outcomes for each player-server match, including co-play, chat engagement, sustained play, and return visits, using player history, game characteristics, and live server state.\nDesign and productionize candidate-server retrieval, ranking, and assignment algorithms that optimize this objective under real-time latency, capacity, and reliability constraints, accounting for both the joining player and players already in the server.\nLead other engineers by example and through technical direction as an individual contributor, mentor engineers, and create an engineering culture of excellence.\nBuild and evolve the data, feature, training, serving, and evaluation systems that support matchmaking ML, ensuring fresh signals, reliable predictions, and consistency between training and serving.\nPartner with Discovery, Search, developer-facing product teams, modelers, and data and AI infrastructure engineers to co-design models and systems that adapt to each game’s needs and deliver value across the player journey.\nDefine offline evaluation and lead online experiments to measure the impact of matchmaking decisions on player engagement and retention, developer success, and system efficiency, using the results to improve models and objectives.\nTranslate research into iterative production improvements, collaborate with the wider ML community where applicable, and represent Roblox’s technical work.\nYou Have:\n8+ years of experience and a consistent record of delivering and improving large-scale ML systems for ranking, recommendation, personalization, or resource allocation.\nExperience defining objective functions, building predictive models, and deploying optimization algorithms that balance user and business outcomes with production latency, reliability, and resource constraints.\nThe capability of breaking down long-term product requirements into iterative deliverable stages.\nInitiated and facilitated challenging technical decisions across multiple teams and organizations. You are empathetic and find common understanding.\nDeep technical expertise, you always start with the needs of the user, whether they are Roblox users or internal engineers.\nA generalist approach and you have mastered several languages and technologies already; you can easily adapt to any situation.\nThe ability to roll up your sleeves to tackle data problems or machine learning problems when they come up.\nA creative and strategic approach to solving hard problems. You simplify the complex. You bring in fresh ideas from new places.\nBS in Computer Science or a related discipline, MS/PhD are a definite plus.\nFor roles that are based at our headquarters in San Mateo, CA: The starting base pay for this position is as shown below. The actual base pay is dependent upon a variety of job-related factors such as professional background, training, work experience, location, business needs and market demand. Therefore, in some circumstances, the actual salary could fall outside of this expected range. This pay range is subject to change and may be modified in the future. All full-time employees are also eligible for equity compensation and for benefits as described on this page.\nAnnual Salary Range\n$295,250—$345,040 USD\nRoles that are based in an office are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday (unless otherwise noted).\nRoblox provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws. Roblox also provides reasonable accommodations to candidates with qualifying disabilities or religious beliefs during the recruiting process.\nFor US based roles only, please note the Company may not be able to employ candidates for this role who have United States work authorization related to certain U.S. visa categories, or support future H-1B sponsorship at this time.","description_format":"text","description_chars":6335,"description_truncated":false,"requirements":{"experience_years_min":8,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"bachelor","optional":false},"security_clearance":false,"languages":[]},"benefits":["Equity"],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Dating & Relationships","Mobile Games","Game Development","Metaverse"],"lifecycle":[{"event":"open","at":"2026-11-04T04:07:24Z"}],"visa":[{"country":"US","licensed_sponsor":true,"adverts_offering_sponsorship_24m":239,"sanctioned_now":false,"evidence":"H-1B filings in 12 months: 247 · green card filings: 82","filings_12m":247,"filings_prev_12m":236,"green_card_filings_12m":82,"median_offered_wage_usd":245038,"route":null,"cap_exempt":false,"checked_at":"2026-11-09T07:32:21+00:00","sources":["US Department of Labor: LCA disclosure data (H-1B, H-1B1, E-3)","US Department of Labor: PERM disclosure data (green cards)","Alion: sponsorship offered in the employer's own job adverts (24 months)"],"filings_for_role_12m":189}],"liveness":{"score":63,"band":"ok","label":"Likely open","p_open":1,"p_active":0.632,"p_room":1,"age_days":5,"expected_fill_days":66,"reasons":["conf:2","stale_co","velocity","win:early","comp:brand"],"computed_at":"2026-11-09T06:03:00Z"},"pay":{"stated_usd_annual":345040,"is_top_pay":true},"html_url":"https://alion.io/job/roblox-corporation-principal-machine-learning-engineer-matchmaking","json_url":"https://alion.io/job/roblox-corporation-principal-machine-learning-engineer-matchmaking.json","meta":{"generated_at":"2026-11-10T06:12:14Z","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":14390,"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":246},"rest":"https://alion.io/mcp/rest/get_company?id=246"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Froblox-corporation-principal-machine-learning-engineer-matchmaking"},{"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%2Froblox-corporation-principal-machine-learning-engineer-matchmaking"},{"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%2Froblox-corporation-principal-machine-learning-engineer-matchmaking"},{"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/roblox-corporation-principal-machine-learning-engineer-matchmaking\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Froblox-corporation-principal-machine-learning-engineer-matchmaking"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":3723670}},{"tool":"search_jobs","arguments":{"company":"roblox.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":3723670},"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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