Senior Full-Stack Engineer

Scale Army

What You ll Do:

• Payments & Money Movement:

  • Design, implement, and harden payment flows (auth/capture, refunds, chargebacks, payouts) with Stripe/Stripe Connect or similar.

  • Build reliable webhooks with strict idempotency, retries/DLQs, and reconciliation jobs that keep internal ledgers in sync with processors.

• System Design & Delivery:

  • Implement complex features with flexibility, security, and extensibility in mind.

  • Ship features across back-end and light front-end (HTML/CSS/JS; React as needed) with incremental, zero-downtime releases.

• Reliability & Operations:

  • Profile and optimize hot paths to keep p95/p99 low during on-sale spikes.

  • Participate in an engineering on-call rotation for major launches; drive incident response and thorough post-mortems.

  • Build all features as if they are going to run at large scale.

• Security, Compliance & Enterprise Readiness:

  • Implement secure coding practices (OWASP/ASVS), secrets hygiene, least privilege (IAM), and encryption in transit/at rest.

  • Be aware of common exploit techniques.

  • Work to best practices with regards to access control, auditability, rate limiting, abuse prevention, and privacy-by-design patterns.

• Data & Reporting:

  • Write and tune complex MySQL queries and indexes; design safe migrations.

  • Turn ad-hoc analyses into durable reporting endpoints and dashboard views.

• Messaging & Integrations:

  • Build resilient RabbitMQ workers with backpressure, DLQs, idempotency, and observability.

  • Integrate external APIs (payments, messaging, identity) safely with circuit breakers and timeouts.

• Platform Health:

  • Raise test coverage (unit/functional), enforce static analysis, and pay down targeted technical debt.

  • Mentor peers via design reviews, pairing, and clear technical writing.

You Have (Required):

• 5+ years building and operating large-scale PHP systems (OO PHP, Composer, PHPUnit, modern language features).

• Payments expertise: production experience with Stripe/Stripe Connect; deep knowledge of refunds, disputes/chargebacks, payouts, reconciliation/ledgering, 3DS2/SCA, and robust webhook design.

• MySQL mastery: schema design, advanced joins, indexing, query plans, and zero-downtime migrations.

• Distributed systems fundamentals: queues, idempotency, retries, timeouts, rate limiting, caching.

• Proven ability to debug live issues and land safe fixes under pressure.

• Front-end fundamentals (JavaScript/HTML/CSS); React familiarity is a plus.

Nice to Have:

• Experience with international payment gateways where local e-wallets are more commonly used than credit and debit cards.

• Go/Rust for targeted high-throughput services; gRPC/OpenAPI; Protobuf/Avro and schema evolution.

• Observability: Sentry, structured logging, tracing.

• Containers & IaC: Docker, ECS/EKS, CloudFormation.

• Fraud/risk systems, rate-limiting and bot mitigation, or anti-scalping experience.