Senior Python Developer and Test Automation Engineer

Mizuho•New York, NY

1d•Hybrid

About The Position

Join Mizuho as a Senior Python Developer and Test Automation Engineer! In this role you will be responsible for the design, development, automation, and support of applications and system components using Python, including but not limited to automation scripts, batch jobs, test automation frameworks, and backend processing components. The role requires full ownership of assigned applications and automation tasks across the SDLC, including development, unit testing, system testing, change management, production releases, and production support. A key expectation is a strong focus on automated testing (BDD), application performance, and system stability to ensure reliable and resilient operations.

Requirements

At least 8–10 years of professional development experience.
Expert-level experience with Python development.
Strong hands-on experience with automation using Python scripts for jobs, workflows, and system processes.
Proven experience with test automation using BDD frameworks (e.g., Behave, pytest-bdd).
Strong focus on unit testing using Python testing frameworks (pytest, unittest, mocking libraries).
Demonstrated ability to build reliable, high-performance, and stable Python applications and batch jobs.
Experience with job scheduling, batch processing, and file/data processing.
Experience integrating automation and tests into CI/CD pipelines.
Solid understanding of object-oriented programming, modular design, and clean code practices.
Experience working with relational databases and SQL.
Strong troubleshooting skills and ability to resolve production issues under pressure.
Ability to analyze and document business processes, automation flows, and system behavior.
Bachelor’s degree or equivalent in Computer Science or related field.
Strong verbal and written communication skills.
Strong analytical, problem-solving, and multi-tasking abilities.
Ability to work effectively with end users, technical teams, and management as needed.

Nice To Haves

Experience in banking, financial services, or other regulated environments preferred.
Experience with REST APIs and integration automation.
Experience with messaging or event-driven processing.
Exposure to container platforms (Docker, Kubernetes/OpenShift).
Familiarity with Linux/Unix environments.
Experience with performance profiling, logging frameworks, and observability tools.
Experience with cloud platforms (Mainly Azure).

Responsibilities

Perform system and requirements analysis and translate business and operational requirements into automated Python solutions.
Design and develop Python-based automation scripts to automate jobs, workflows, data processing, and operational tasks.
Build and maintain backend Python applications and scheduled/batch processes with clear restart, recovery, and error-handling mechanisms.
Develop reusable libraries, utilities, and frameworks to standardize automation and testing patterns.
Apply well-accepted design patterns and best practices to ensure maintainable, scalable, and secure Python code.
Document technical designs, automation flows, and operational procedures.
Design and implement test automation frameworks using BDD tools (e.g., Behave, pytest-bdd, Cucumber-style frameworks).
Develop automated test suites covering functional, regression, and integration scenarios.
Enforce strong unit testing practices using Python testing frameworks; define coverage and quality expectations.
Integrate automated tests into CI/CD pipelines to ensure early defect detection and regression prevention.
Participate in planning and execution of DUT, SIT, and UAT, coordinating closely with QA and business teams.
Support defect analysis, remediation, and re-testing activities.
Ensure test evidence and documentation are produced to meet audit and compliance requirements where applicable.
Proactively identify and resolve performance bottlenecks in Python scripts and applications.
Improve system stability through robust exception handling, retries, idempotency, and resource management.
Tune batch jobs and automated processes for efficiency, scalability, and predictable execution.
Establish logging, monitoring, and alerting standards for automated jobs and backend processes.
Manage issues and enhancements using tools such as JIRA or equivalent issue tracking systems.
Provide production support, including incident triage, root-cause analysis, and timely resolution of issues.
Support operational controls such as certifications, password rotations, vulnerability remediation, and audit activities.
No direct reports; however, this person should be able to run small to medium initiatives, support other developers, and provide technical guidance.
Coordinate with infrastructure, DevOps, and other technology teams to deploy and operate automation solutions.
Take complete ownership of assigned tasks and manage priorities with minimal daily supervision.