Senior AWS Engineer

Location: Malvern

Pay Range: $55.00hr - $60.00hr Job Overview:
Our client is seeking a Senior AWS Engineer to extend an event-driven, serverless financial platform. The platform combines Python-based AWS Glue ETL pipelines with Node.js Lambda microservices. Responsibilities:
Design, build, and maintain independently deployable microservices (single-purpose AWS Lambda functions) within an event-driven architecture. Develop and maintain Node.js (ES6+/async-await) Lambda microservices for file intake, validation, transformation, submission, and acknowledgement handling of transaction files (JSON, XLSX, CSV). Build event-driven Node.js services triggered by S3 event notifications, Event Bridge, SQS, and API Gateway, with clear contracts between services. Use the AWS SDK for Node.js

(v3 preferred) to integrate with core AWS services such as S3, DynamoDB, SNS/SES, Secrets Manager, and Step Functions. Manage dependencies, Lambda layers, bundling, and cold start/memory/timeout tuning for Node.js functions. Define clean service boundaries and contracts (event payloads, schemas, S3 formats) enabling independent development and deployment. Maintain and extend AWS Glue ETL jobs (PySpark + native Oracle JDBC) that ingest, transform, and reconcile daily transaction history and position snapshot files.

Build and troubleshoot Step Functions workflows (ASL state machines) orchestrating multi-stage pipelines: file validation, ingestion, reconciliation, and alerting. Design and maintain Lambda functions (Python and Node.js) for lightweight orchestration, file validation, DynamoDB writes, and SNS/SES alerting. Write and optimize Oracle SQL (native JDBC and Lambda-proxied) against a complex financial schema. Manage DynamoDB data models for transaction history, reconciliation status, and fund-level summaries, including GSIs and TTL-based retention.

Implement robust error handling and transactional integrity (per-record commit/rollback, idempotency, duplicate-detection) for financial data where silent failures are unacceptable. Apply retries, dead-letter queues, and idempotency keys (for example, a file  with DynamoDB conditional writes) so S3 events delivered more than once never cause duplicate processing. Own unit, integration, and smoke test suites (pytest/unittest, Jest/Mocha, moto, and aws-sdk-client-mock for AWS mocking) and maintain/improve code coverage.

Support CI/CD pipelines (Jenkins, AWS SAM/Cloud Formation), including build, test, lint, and packaging of Node.js services. Build and maintain observability: structured Cloud Watch logging/metrics, Grafana dashboards, and metric registries for pipeline health. Participate in security reviews (SOC2-aligned findings, SQL injection guards, least-privilege IAM, KMS encryption) and remediate findings, including Node.js dependency vulnerability management (npm audit). Produce and maintain technical documentation (architecture references, runbooks, deployment guides, change logs).

Required

Skills & Experience:

Strong proficiency in Python (3.12+), including testable, well-structured ETL code. Strong proficiency in Node.js (current LTS), including ES6+, async/await, and JavaScript or Type Script for AWS Lambda microservices. Experience designing and operating microservices architectures: single-purpose services, loose coupling, independent deployment, event contracts, and idempotency. AWS Glue (PySpark, Glue 4.0, Dynamic Frames) and AWS Lambda (Python and Node.js runtimes). AWS Step Functions (Amazon States Language) for workflow orchestration.

AWS SAM / Cloud Formation infrastructure as code, multi-environment deployment. Oracle SQL complex joins, DML across transactional schemas, stored procedure like code patterns. DynamoDB key design, GSIs, conditional writes, pagination. S3 - event-driven architectures (Event Bridge notifications), data lake patterns (Parquet). Strong testing discipline: pytest/unittest, Jest/Mocha, mocking AWS services (moto, aws-sdk-client-mock), stubbing Spark/Glue runtime dependencies for offline unit tests.

Experience with financial/transactional data where correctness, auditability, and idempotency are critical. CI/CD experience, ideally Jenkins, with multi-environment promotion gates. Familiarity with Cloud Watch metrics/logs, Grafana, and building operational dashboards. Benefits:
Our Benefits Include:
Medical, Dental, and Vision Insurance 401(k) Retirement Plan Health Savings Account (HSA) Disability Insurance (Short-Term and Long-Term) Life and AD&D Insurance Paid Sick Leave…