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 NestJS
• Build and optimize data pipelines connecting BigQuery, MongoDB
• Code asynchronous communication patterns using Cloudflare Queues and WebSockets for real-time updates
• Leverage edge Workers with R2, D1, Blob store
• Collaborate with AI/ML team to integrate OpenAI, Claude, Llama, and custom Prophet forecasting models
• Participate in system design decisions for multi-region deployment and disaster recovery strategies
• Mentor junior engineers and contribute to technical documentation

Required Qualifications

• 5+ years of back-end development experience, with at least 2 years in senior/lead roles
• Expert proficiency in TypeScript and Node.js
• Deep understanding of microservices architecture, event-driven systems
• Hands-on experience with both SQL (BigQuery) and NoSQL (MongoDB) databases at scale
• Proven track record building financial or payment processing systems
• Experience with message queuing systems and asynchronous processing patterns
• Strong knowledge of API design principles, RESTful services, and OpenAPI specifications
• Expertise in cloud-native development, preferably with AWS, Cloudflare
• Solid understanding of security best practices, authentication/authorization patterns

Nice to Have

• Experience with AI/ML integration
• Background in FinTech, lending, or alternative financing
• Python knowledge
• Working with LLM APIs (OpenAI, Claude, etc.)
• Knowledge of financial compliance, KYC/AML processes, and regulatory requirements
• Familiarity with Cloudflare's ecosystem (Workers, R2, D1, Queues)
• Experience with event sourcing, CQRS patterns, and complex state management
• Proficiency with Infrastructure as Code tools like Pulumi
• Experience with real-time data processing and WebSocket implementations

Tech Stack Highlights

• Backend: TypeScript, NestJS, Node.js
• Databases: BigQuery, MongoDB, Redis
• Cloud Infrastructure: Cloudflare (Workers, Pages, R2, Queues), Azure, Kubernetes
• AI/ML: OpenAI, Claude, Llama, Grok, Prophet
• Payments & Banking: Stripe, GoCardless
• Monitoring: New Relic, Sentry
• Security: 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 challenges
• Flexible 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 technologies
• Direct impact on product direction and technical architecture
• Collaborative environment
• Regular team events and offsites
• Ample opportunities for professional growth and development, empowering you to reach new heights in your career.

Interview Process

1. Initial screening (20 minutes)
2. Technical test (90 minutes)
3. Cultural fit interview with leadership (45 minutes)
4. Reference checks and offer

How to Apply

Send your CV and a brief note about why you're excited to work in FinTech to [email protected]

Please include:

• Links to your GitHub/GitLab profile
• Examples of production systems you've built
• Your experience with our tech stack
• What 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.