Software Development Engineer III

We're looking for a Software Development Engineer III (SDE III) with strong backend expertise and enough full-stack capability to own features end-to-end.

What the role is really about (backend-heavy):
You'll join our Wallet team that powers Wallet, Billing, Taxes, and related services. Your focus will be on foundational, platform-level work:
Ensuring rock-solid system stability and performance under growing load. Driving scalability, tech debt reduction, security hardening, and cost optimization Solving complex distributed systems challenges that keep the entire Wallet ecosystem reliable and efficient.

This is a backend-first, full-stack role; you'll spend most of your time on architecture, performance, and infrastructure while still being able to ship complete features when required. If you love deep backend problems and want to own the stability and scalability of a mission-critical product, this is for you.

• Own end-to-end feature delivery for the Wallet, Billing, and Taxes platform - from API design and backend implementation to necessary Vue.js frontend changes.
• Build and maintain highly stable, performant, and scalable backend services using Node.js, Mongo
  
  DB, and distributed systems patterns.
• Identify and fix systemic issues (crashes, time-outs, race conditions, memory leaks, etc. ) to improve overall platform reliability.
• Drive performance optimizations and cost-efficiency improvements (query tuning, caching strategies, indexing, reducing cloud spend).
• Actively reduce technical debt by refactoring critical parts of the codebase, improving test coverage, and eliminating anti-patterns.
• Implement and enforce security best practices (input validation, auth flows, secrets management, rate limiting, etc. ) in every change.
• Enhance observability - add meaningful logs, metrics, alerts, and tracing to make issues easier to debug in production.
• Collaborate closely with QA from day one: review test cases, perform live demos during QA handover, and quickly address feedback.
• Contribute to internal tooling and automation that speeds up development and deployment cycles.
• Pair with other engineers, share knowledge, and help unblock teammates when needed.
• Participate in on-call rotation and resolve production incidents for the services you own.
• This is a hands-on IC role where you'll write a lot of production code, ship frequently, and directly impact the stability and scalability of our Wallet platform.

• Deep expertise in Node.js, Mongo
  
  DB, Vue.js, and distributed systems.
• Proven track record in building highly stable, scalable backend platforms.
• Comfortable contributing to the frontend when needed (this is not a UI-heavy role).
• 4-7 years of backend engineering experience with proven exposure to scale (high TPS, large datasets, or multi-tenant environments).
• Expert-level Node.js and a strong track record of writing clean, modular, reusable code.
• Deep expertise with Mongo
  
  DB (complex schemas, aggregation pipelines, indexing, and sharding).
• Solid production experience with Redis (caching, rate-limiting, pub/sub, and distributed locks).
• Hands-on experience building and running microservices on Kubernetes (basic K8s knowledge is sufficient - deployments, services, configmaps, etc. ).
• Strong hands‑on experience with any major cloud provider (GCP, AWS, or Azure) you know how to use managed services for containers, queues, caches, serverless, and databases effectively.
• Comfortable contributing to the frontend using any modern UI framework (Vue.js, React, or Angular Vue.js experience is a plus but not mandatory).
• You've shipped and supported large-scale, mission-critical systems that stayed stable under heavy load. You love modular architecture, obsess over performance and cost on GCP, and can jump into the frontend when needed to ship complete features.

• Experience with AI tools and contributions to open-source tools, internal platforms, or engineering blogs.
• NestJS or Express.js experience.
• Elasticsearch for search/filtering use cases.
• Exposure to any OLAP system (Click House, Snowflake, Big Query, etc. ).