Kamipay - Sr Backend Engineer (Python)

From Silver

We are looking for outstanding talent looking to make an impact and be a technical leader at a highly critical payment infrastructure engineering organization.

The compensation listed is estimated and heavily based on concrete experience in the industry and in systems that handle money critically.

About KamiPay

Mission:
Build and scale kamiPay core solution powering real-time cross-border payments via blockchain and RTP systems like Pix and Transferencias 3.0.

Key Focus:
We seek a proven Senior BackEnd Software Engineer who has architected, developed, deployed, and maintained mission-critical systems handling high transaction volumes (e.g., fintech, banking, or distributed platforms). You must demonstrate experience scaling systems from early-stage MVP to production-grade reliability and have a track record of solving scalability, latency, and resilience challenges.

Why Join kamiPay?

• Solve hard problems at the intersection of blockchain and real-time payments across multiple countries.

• Work with a team that’s shipped production-grade fintech systems (no “theoretical” engineering).

• We have Product Market Fit: If you heard the word Pix in Argentina, it's because kamiPay introduced it to the market.
  

Technical Skills:

• 7+ years of BackEnd development with Python (async frameworks like FastAPI, Django) and SQL.

• Strong expertise in designing RESTful APIs for high-traffic systems (1k+ TPS) with strict SLAs.

• Hands-on experience with cloud architectures (AWS preferred: ECS, Lambda, RDS, SQS/SNS).

• Proven ability to build async task processing (Celery, Redis) for real-time payment transactions, reconciliation, fraud checks, or batch processing.

• Good DevOps Practices: CI/CD (GitHub Actions), IaC (Terraform), and monitoring (Sentry, Cloudflare, Cloudwatch, Prometheus, Grafana, Datadog).

• Observability-Driven Development: Built systems with observability "baked in" (custom Sentry tags, structured logging, metrics for business-critical transactions).

• Hands-on experience with error-tracking tools like Sentry to debug, diagnose, triage, and resolve issues in real-time.

• Familiarity with performance profiling (e.g., identifying memory leaks, slow SQL queries) in high-throughput systems.

• Production Battle Scars:

  • Shipped systems that process 300K+ daily transactions or handle 5k+
    concurrent users.

  • Experience with financial-grade uptime (99.99%+) and disaster recovery (multi region/active-active setups).

  • Debugged and resolved production incidents (e.g., race conditions, deadlocks, API throttling).

• Scalability from Scratch:

  • Built systems from MVP to scale (e.g., re-architected monoliths to microservices,
    optimized databases for low-latency queries).

  • Implemented performance tuning (caching with Redis, query optimization, load
    and stress testing).

• Familiarity with payment rails (Pix, SEPA, SWIFT, Transferencia 3.0, etc) or blockchain (crypto wallets, send transactions). (Nice to have)

Responsibilities

• Design, build, and maintain APIs and services that integrate with banking partners, crypto wallets, and RTP systems.

• Ensure zero-downtime deployments and real-time monitoring/alerting for transaction failures.

• Lead scalability efforts (e.g., sharding databases, horizontal scaling of payment processing workers).

• Conduct rigorous load testing and chaos engineering (e.g., simulating payment failures, network partitions).

• Collaborate with security teams to enforce financial-grade auth (OAuth2, JWT, WebAuthn) and encryption.

• Architect and maintain Sentry configurations to track errors, exceptions, and performance bottlenecks across services (APIs, async workers, blockchain integrations).

• Lead post-mortems for production incidents, using Sentry data to identify root causes and implement preventive measures.

• Define and monitor key error budgets (e.g., <0.1% transaction failure rate) with actionable alerts for team response.

• Collaborate with DevOps to integrate Sentry with incident management tools (Opsgenie, PagerDuty) for real-time escalation.
  

What You’ll Bring:

• Proven Impact:

  • Portfolio of production systems you’ve scaled (share metrics: transactions/sec, error rates, p99 latency).

  • Examples of architectural decisions you drove.

• Ownership Mentality:

  • Experience being the “go-to” engineer during outages or critical launches.

  • Built systems where a 1-minute downtime = $10k+ losses.

• Fintech Pragmatism:

  • Ability to balance speed vs. robustness (e.g., shipping fast while maintaining audit trails for compliance).

  • Intuition for what matters in payments (idempotency).

• Communication:

  • Translate technical trade-offs into business terms (e.g., “Using Redis Cluster adds $5k/month but reduces latency by 300ms”).

• Battle-Tested Debugging:

  • Examples of resolving race conditions (e.g., duplicate payments due to concurrent API requests) using distributed locks or idempotency keys.

  • Experience tuning garbage collection in Python to prevent memory leaks under sustained load.

• Proactive Optimization:

  • Strategies to improve performance and avoid contention, such as: Sharding databases, Rate limiting, Batching operations