{"id":3629528,"url":"https://alion.io/job/arena-back-end-engineer-brazil","title":"Back end Engineer [Brazil]","company":{"id":1768233,"name":"Arena","domain":"arena.im","url":"https://alion.io/company/arena-im","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"B","score":75,"open_postings":5,"ghost_share":0,"stale_share":1,"repost_share":0,"time_to_fill_p50_days":null,"computed_at":"2026-11-03T05:54:40Z"}},"role":"Backend","role_family":"Backend","seniority":"middle","employment_type":null,"work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"posting_text","remote_working_hours":null,"hiring_geo_confidence":"explicit","locations":["São Paulo, Brazil","Brazil"],"countries":["BR"],"hiring_countries":["BR"],"hiring_countries_total":1,"salary":null,"salary_estimate":null,"experience_years_min":3,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AI Agents","optional":false},{"name":"Amazon DocumentDB","optional":false},{"name":"AWS","optional":false},{"name":"Fine-tuning","optional":false},{"name":"Go","optional":false},{"name":"Multimodal AI","optional":false},{"name":"Node JS","optional":false},{"name":"RAG","optional":false},{"name":"Rest API","optional":false},{"name":"TypeScript","optional":false},{"name":"Amazon CloudWatch","optional":true},{"name":"Amazon EC2","optional":true},{"name":"Amazon Kinesis","optional":true},{"name":"Amazon S3","optional":true},{"name":"API Gateway","optional":true},{"name":"AWS Fargate","optional":true},{"name":"AWS Lambda","optional":true},{"name":"C#","optional":true},{"name":"Cloudflare","optional":true},{"name":"Discord","optional":true},{"name":"DynamoDB","optional":true},{"name":"Firebase","optional":true},{"name":"Firestore","optional":true},{"name":"GraphQL","optional":true},{"name":"IAM","optional":true},{"name":"Java","optional":true},{"name":"JavaScript","optional":true},{"name":"LLM","optional":true},{"name":"PostgreSQL","optional":true},{"name":"React.js","optional":true},{"name":"Redis","optional":true},{"name":"SQL","optional":true},{"name":"WebSockets","optional":true},{"name":"WhatsApp","optional":true}],"status":"live","first_seen_at":"2025-02-06T16:16:42Z","employer_posted_date":"2026-10-06","last_verified_at":"2026-11-04T00:54:34Z","board_verified":true,"closed_at":null,"days_open":635,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":634},"description":"About Arena:\nArena is a Series A company backed by top-tier investors such as CRV, Redpoint and Craft Ventures. Arena offers a unique work environment and the chance to collaborate with diverse teammates across multiple countries, with a culture of ownership (autonomy, growth, and responsibility). \nWe are a startup created in Silicon Valley with a mission to build communities for creators, publishers and brands with the power of AI. Companies using Arena include Disney, Reuters, Fox, Red Bull and NFL. We have +2,000 customers in 150 countries and with +50M users having conversations on Arena per month and engaging with our Agent AI.\nArena is also expanding its AI product portfolio with MyAvatar.AI, a multimodal platform that enables users to create intelligent, personalized AI avatars through voice, video, and conversational interfaces.\nSometimes you're stuck in a job that doesn't make sense. Refactoring code from ages ago, the stack is miles away from what it's supposed to be. If you love a good challenge, enjoy solving meaningful problems, and want to be a part of one of the fastest-growing AI startups in the Silicon Valley - then Arena is the company you're looking for.\nWhat you will be doing:\nOur team is made up of very experienced engineers, some with more than 10 years of experience. You will have an enormous impact on making our app and API service faster, more scalable and more flexible. You will collaborate with product and engineering teams to ship AI-powered features and make the existing ones perform orders of magnitude faster. \nThe challenges:\nReal-time messaging to support 500,000 concurrent users per customer application;\nHigh performance: our API responses are in the 10ms range;\nDesign and build AI Agents, RAG pipelines, model fine-tuning and crawling.\nHigh scalability: we use sharding, master-master, and master-slave to ensure scalability;\nHigh availability: our code is running on homepages of the most visited websites and apps on the internet;\nDistributed databases for our Data Platform storing every user engagement.\nOur Stack:\nNode.js, TypeScript;\nGolang;\nWebsocket;\nApollo GraphQL;\nAWS Lambda/Serverless framework;\nAWS (API Gateway, S3, VPC, IAM, Fargate, EC2, ALB, CloudFront, Kinesis, SQS, CloudWatch);\nGoogle Firestore/Firebase;\nMongoDB, PostgreSQL, DynamoDB;\nRedis;\nCloudflare;\nUnit test.\n Work Experience:\n3+ years as a backend developer\nExperience with high-traffic and high-performance applications\nCurious developer who experiments with AI and AI agents everyday.\nMust-Have Experience:\nTypeScript;\nNode.js;\nTDD, BDD, or ATDD;\nREST APIs;\nMongoDB, AWS DocumentDB, or other document database;\nNice-to-Have Experience:\nExperience with statically typed languages (e.g. Java, C#, Go);\nObject-oriented and functional programming;\nGolang;\nAWS;\nSQL;\nReact.\nExample Projects You’ll Be Working on:\nBuild a real-time chat that can scale to 1M simultaneous users;\nDesign, optimize and scale AI agent-based architectures, RAG pipelines, and other LLM-driven systems.\nIntegrate systems with data sources and handle millions of first-party data.\nBuild complex business rules orchestrations similar to Reddit, Discord, and Whatsapp. \nWe also have some sweet perks like:\nBe a part of the team in Silicon Valley and join a global team.\nA team of exceptional engineers leading the cutting-edge AI Agents.\nCompetitive salary package & benefits.\n4 weeks of paid time-off.\nLearning and Development budget.\nKey moment to join Arena in terms of growth and opportunities.\nAbility to put your stamp on real-world AI applications that serve millions of users.\nFast-learning environment, entrepreneurial and strong team spirit.\nMultiple nationalities: cosmopolite & multi-cultural mindset.\nOur people matter, work-life balance is important at Arena.","description_format":"text","description_chars":3784,"description_truncated":false,"requirements":{"experience_years_min":3,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[{"name":"Brazil","iso":"BR","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Commerce","Events & Ticketing","Venues"],"lifecycle":[{"event":"open","at":"2026-11-02T20:27:39Z"}],"visa":[],"liveness":{"score":5,"band":"cold","label":"Long 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