As our Lead Backend & Integration Engineer, you will be the hands-on engineering anchor for our NestJS core monorepo (yapay-backend-core). You will lead the design and implementation of our provider-neutral Anti-Corruption Layer (ACL), build high-throughput transactional outbox pipelines, and maintain strict domain boundaries across our payment orchestration services.

You will work closely with our Solutions Architect and Product Lead, writing production code from Day 1, conducting peer code reviews, and setting the standard for automated testing, security, and type safety across our services.

What Youll Do

- Build the BaaS Anti-Corruption Layer (ACL): Design and maintain provider-neutral interfaces (IBankingProvider) in NestJS, ensuring domain logic remains strictly decoupled from external partner SDKs, schemas, or raw wire protocols.
- Architect Distributed Workflows: Build resilient, decoupled outbox publishing engines using TypeORM pessimistic row locking (SKIP LOCKED) and AWS SQS message pipelines to execute idempotent state machine transitions.
- Enforce Clean Monorepo Architecture: Structure and maintain NestJS monorepo boundaries (apps/ for deployable services like APIs, webhook ingress, and async workers; libs/ for pure domain models, ports, and infrastructure adapters).
- Manage Transactional & Data Integrity: Implement TypeORM domain entities, manage optimistic concurrency controls (version), build non-negative monetary value objects (BigInt / ISO 4217), and execute non-blocking schema evolution patterns.
- Lead Security & Quality Gates:



Enforce RFC 9457 error response standards (application/problem+json), implement field-level KMS envelope encryption for sensitive payload data, ensure zero Class 4 PII leaks into application logs, and maintain strict automated test coverage thresholds ($ge 85%$ global, $100%$ on core state transition branches).Role & responsibilities

Preferred candidate profile

- 7+ years of senior or lead software engineering experience building high-throughput, low-latency distributed systems or payment platforms.
- Expert TypeScript & NestJS Mastery: Deep experience with TypeScript strict: true, Node16 module resolution, NestJS monorepo architecture, custom modules, agile providers, interceptors, and custom pipes.
- PostgreSQL & TypeORM Proficiency: Hands-on experience with explicit database transactions, optimistic locking (version), pessimistic row locking (FOR UPDATE SKIP LOCKED), partial unique indexing, and migration pipelines.
- Asynchronous Messaging & Outbox Patterns: Proven track record building transactional outbox workers, dead-letter queue (DLQ) retry strategies, and idempotent consumers using AWS SQS and EventBridge.
- Security & Cryptographic Foundations: Practical understanding of OAuth 2.0 credential management with Redis distributed locks, AES-256-GCM envelope encryption, HMAC blind indexing, and cryptographic signature verification.

Test Rigor & Engineering Discipline: Experience with Jest, Testcontainers, Supertest, LocalStack, and OpenAPI / Pact contract testing.

📌 Lead Backend & Integration Engineer (NestJS / FinTech ACL Lead) (Hyderabad)
🏢 Yapay Payments
📍 Hyderabad