We are looking for Senior AWS Engineer for our client in Malvern, PA
Job Title: Senior AWS Engineer
Job Location: Malvern, PA
Job Type: Contract
Pay Range: $53.00hr - $58.00hr
Job Overview:
The organization is looking for 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, EventBridge, 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, 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 ID checked 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/CloudFormation), including build, test, lint and packaging of Node.js services.
- Build and maintain observability: structured CloudWatch 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, changelogs).
Required Skills & Experience:
- Python (3.12+) strong proficiency, including testable, well-structured ETL code.
- Node.js (current LTS) strong proficiency, including ES6+, async/await, and JavaScript or TypeScript 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, DynamicFrames) and AWS Lambda (Python and Node.js runtimes).
- AWS Step Functions (Amazon States Language) for workflow orchestration.
- AWS SAM / CloudFormation 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 (EventBridge 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 CloudWatch metrics/logs, Grafana, and building operational dashboards.
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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 (where required by applicable state or local law)
- Supplemental Insurance Plans
- Identity Theft Protection
- Pet Insurance
- Employee Wellness Programs
- Employee Assistance Program (EAP)
- Career Growth and Professional Development Opportunities
Disclaimer: Benefits eligibility, accrual rates, and usage limits may vary based on employment status, length of service, and work location. Paid Sick Leave is provided in strict accordance with applicable state and municipal mandates. Cynet Systems Inc. reserves the right to modify, amend, or terminate any benefit plans at any time in accordance with applicable laws.
About Cynet Systems
Founded in 2010 and headquartered in the Washington, DC metro area, Cynet Systems Inc. is a leading technology staffing and workforce solutions company serving Fortune 500 companies, government agencies, and enterprise organizations across the United States and Canada. We deliver agile, scalable talent solutions across IT, engineering, life sciences, clinical, and professional staffing, powered by a high-performing recruitment engine operating across North America and Asia.
As a nationally and locally certified Minority Business Enterprise (MBE), Cynet Systems is committed to helping organizations build high-performing teams while empowering professionals to grow rewarding careers. Our organization is certified to ISO 9001, ISO 14001, ISO 27001, and SOC 2 Type II standards, reflecting our commitment to quality, security, operational excellence, and customer success.
