AWS Engineer

About The Company Cynet Systems, established in 2010 and headquartered in the Washington, D.C. metro area, is a premier technology staffing and workforce solutions provider. The company specializes in delivering agile, scalable talent solutions across a broad spectrum of industries, including IT, engineering, life sciences, clinical, and professional staffing. Serving Fortune 500 companies, government agencies, and enterprise organizations across the United States and Canada, Cynet Systems has built a reputation for excellence and reliability. As a certified Minority Business Enterprise (MBE), Cynet Systems is committed to fostering diversity and inclusion within the workforce. The organization maintains certifications such as ISO 9001, ISO 14001, ISO 27001, and SOC 2 Type II, underscoring its dedication to quality, security, operational excellence, and customer satisfaction. About The Role Cynet Systems is seeking a highly skilled Senior AWS Engineer to join our client's dynamic team. This role is pivotal in extending and enhancing an event-driven, serverless financial platform that leverages cutting-edge AWS services. The ideal candidate will possess extensive experience in designing, developing, and maintaining microservices architectures, with a focus on serverless solutions using AWS Lambda, AWS Glue, Step Functions, and related services. The Senior AWS Engineer will be responsible for building robust, scalable, and secure microservices in Node.js and Python, ensuring seamless integration with AWS infrastructure components such as S3, DynamoDB, SNS/SES, Secrets Manager, and API Gateway. The role requires a strong understanding of financial data processing, ensuring data integrity, auditability, and idempotency in a high-stakes environment. This position offers an excellent opportunity to work on complex, mission-critical systems, employing best practices in CI/CD, testing, security, and observability. Qualifications The ideal candidate will have a strong technical background with the following qualifications: Proficiency in Python (version 3.12+), with experience in developing well-structured ETL pipelines and data transformation processes.Expertise in Node.js (current LTS versions), including ES6+, async/await, and JavaScript or TypeScript for AWS Lambda microservices.Hands-on experience designing and operating microservices architectures that emphasize loose coupling, independent deployment, and clear event contracts.Deep knowledge of AWS Glue (PySpark, Glue 4.0, DynamicFrames) and AWS Lambda (Python and Node.js runtimes).Experience with AWS Step Functions (Amazon States Language) for orchestrating complex workflows.Proficiency in infrastructure as code using AWS SAM or CloudFormation for multi-environment deployment.Strong SQL skills, particularly with Oracle SQL, involving complex joins, DML operations, and stored procedures.Experience designing DynamoDB data models, including GSIs, conditional writes, and TTL-based data retention strategies.Knowledge of S3 event-driven architectures, data lake patterns, and data formats such as Parquet.Robust testing discipline with experience using pytest, unittest, Jest, Mocha, and AWS mocking tools like moto and aws-sdk-client-mock.Familiarity with CI/CD pipelines, preferably Jenkins, for multi-environment promotion and automation.Understanding of security best practices, including IAM, KMS encryption, vulnerability management, and SOC2 compliance.Excellent documentation skills for creating architecture diagrams, runbooks, deployment guides, and changelogs. Responsibilities Design, develop, and maintain independently deployable microservices (AWS Lambda functions) within an event-driven architecture, ensuring scalability and reliability.Create and sustain Node.js Lambda microservices responsible for file intake, validation, transformation, submission, and acknowledgment handling of various transaction file formats such as JSON, XLSX, and CSV.Implement event-driven services triggered by S3 notifications, EventBridge events, SQS queues, and API Gateway endpoints, establishing clear contracts and schemas between services.Leverage the AWS SDK for JavaScript (v3 preferred) to integrate Lambda functions with core AWS services like S3, DynamoDB, SNS/SES, Secrets Manager, and Step Functions.Manage dependencies, Lambda layers, bundling, and optimize functions for cold start times, memory, and timeout configurations.Define and enforce clean service boundaries, schemas, and event payload contracts to facilitate independent development and deployment cycles.Maintain and extend AWS Glue ETL jobs using PySpark and native Oracle JDBC, handling ingestion, transformation, and reconciliation of daily transaction data.Build and troubleshoot AWS Step Functions workflows that orchestrate multi-stage pipelines, including validation, ingestion, reconciliation, and alerting mechanisms.Develop lightweight orchestration Lambda functions in Python and Node.js for tasks like file validation, DynamoDB updates, and alert notifications via SNS/SES.Write complex SQL queries and stored procedures against transactional Oracle schemas to support data reconciliation and reporting needs.Design and optimize DynamoDB data models, including GSIs and TTL policies, for transaction history, reconciliation status, and fund summaries.Implement robust error handling, retries, dead-letter queues, and idempotency keys to ensure data integrity and prevent duplicate processing in a high-volume environment.Own and maintain comprehensive test suites, ensuring high code coverage and reliable functionality through unit, integration, and smoke testing.Support CI/CD workflows, including build, test, lint