Senior Back End Engineer

We're seeking an experienced Senior Back-end Engineer to join our core platform team. You'll work on building and scaling our microservices architecture, implementing financial workflows, and integrating AI capabilities into our lending platform. This is an opportunity to shape the technical foundation of a rapidly growing FinTech startup while working with modern cloud-native technologies. Key Responsibilities Design and develop scalable microservices using TypeScript with NestJSBuild and optimize data pipelines connecting BigQuery, MongoDBCode asynchronous communication patterns using Cloudflare Queues and WebSockets for real-time updatesLeverage edge Workers with R2, D1, Blob storeCollaborate with AI/ML team to integrate OpenAI, Claude, Llama, and custom Prophet forecasting modelsParticipate in system design decisions for multi-region deployment and disaster recovery strategiesMentor junior engineers and contribute to technical documentation Required Qualifications 5+ years of back-end development experience, with at least 2 years in senior/lead rolesExpert proficiency in TypeScript and Node.jsDeep understanding of microservices architecture, event-driven systemsHands-on experience with both SQL (BigQuery) and NoSQL (MongoDB) databases at scaleProven track record building financial or payment processing systemsExperience with message queuing systems and asynchronous processing patternsStrong knowledge of API design principles, RESTful services, and OpenAPI specificationsExpertise in cloud-native development, preferably with AWS, CloudflareSolid understanding of security best practices, authentication/authorization patterns Nice to Have Experience with AI/ML integrationBackground in FinTech, lending, or alternative financingPython knowledgeWorking with LLM APIs (OpenAI, Claude, etc.)Knowledge of financial compliance, KYC/AML processes, and regulatory requirementsFamiliarity with Cloudflare's ecosystem (Workers, R2, D1, Queues)Experience with event sourcing, CQRS patterns, and complex state managementProficiency with Infrastructure as Code tools like PulumiExperience with real-time data processing and WebSocket implementations Tech Stack Highlights Backend: TypeScript, NestJS, Node.jsDatabases: BigQuery, MongoDB, RedisCloud Infrastructure: Cloudflare (Workers, Pages, R2, Queues), Azure, KubernetesAI/ML: OpenAI, Claude, Llama, Grok, ProphetPayments & Banking: Stripe, GoCardlessMonitoring: New Relic, SentrySecurity: Auth0, JWT, OAuth 2.0 What We Offer A competitive and motivating income that recognizes and values your contributions.Opportunity to work on cutting-edge AI and FinTech challengesFlexible work schedule to promote work-life balance and accommodate your personal needs.Embrace a non-corporate and cozy work environment, where collaboration and creativity flourish.Modern tech stack with freedom to explore new technologiesDirect impact on product direction and technical architectureCollaborative environmentRegular team events and offsitesAmple opportunities for professional growth and development, empowering you to reach new heights in your career. Interview Process Initial screening (20 minutes)Technical test (90 minutes)Cultural fit interview with leadership (45 minutes)Reference checks and offer How to Apply Send your CV and a brief note about why you're excited to work in FinTech to careers@capital33.com Please include: Links to your GitHub/GitLab profileExamples of production systems you've builtYour experience with our tech stackWhat interests you most about FinTech and AI About Capital 33 Capital 33 is a next-generation merchant bank focused on two core services: capital raising and direct lending for mid-market and large enterprises. We support every stage of corporate growth—from day-to-day working-capital needs to multi-year investment programs—leveraging deep expertise in structured finance, syndicated loans, private debt, and project finance. We're building the future of FinTech by combining cutting-edge artificial intelligence with deep financial expertise to provide startups with the capital they need to grow. Capital 33 is an equal opportunity employer committed to building a diverse and inclusive team. We welcome applications from all qualified candidates regardless of race, gender, age, religion, identity, or experience.