Demo

Python / PySpark (Mainframe Modernization)

Apex Systems
San Francisco, CA Contractor
POSTED ON 5/5/2026
AVAILABLE BEFORE 6/3/2026
Job#: 3033188

Job Description:

Python / PySpark (Mainframe Modernization)

Location: San Francisco, California (Onsite)

Employment Type: Contract

Duration: 12 months

Role Overview

We are seeking a Senior Software Engineer with backend expertise to join a Scrum-based delivery team modernizing a mission-critical financial system. This role is heavily backend-focused, with an emphasis on Python and PySpark, while also contributing to frontend development using React and Angular as needed. This individual will serve as a technical subject matter expert, guiding a team that is upskilling from mainframe technologies. The position requires mentorship, technical guidance, and communication skills to work with Product Owners, Lines of Business, and Operations teams.

Key Responsibilities

  • Design, develop, and modernize backend services to replace legacy mainframe functionality on a distributed platform.
  • Build and maintain data ingestion, validation, and transformation pipelines using Python and PySpark.
  • Develop and support APIs using FastAPI and/or Flask.
  • Collaborate within a Scrum team, partnering closely with Product Owners and stakeholders.
  • Act as a Python SME, mentoring engineers transitioning from mainframe technologies.
  • Contribute to frontend development using React and Angular when required.
  • Ensure data accuracy and integrity for financial feeds flowing into general ledger systems.
  • Participate in technical design discussions, code reviews, and architecture decisions.
  • Communicate effectively through documentation, presentations, and stakeholder discussions.
  • Support CI/CD pipelines and cloud-native deployments using containerized platforms.

Required Qualifications

  • 7 years of relevant professional software engineering experience.
  • Strong expertise in Python, with production experience using PySpark.
  • Backend experience with FastAPI and/or Flask.
  • Frontend experience with React and/or Angular.
  • Experience with SQL Server and/or Exadata.
  • Hands-on experience with Kafka or other streaming platforms.
  • Experience working in Agile / Scrum delivery models.
  • Strong communication, presentation, and stakeholder engagement skills.
  • Ability to guide and mentor other engineers as a senior technical contributor.

Preferred Qualifications

  • Agentic AI frameworks: LangGraph, LangChain, A2A.
  • Programming Languages: Java, Scala, SQL, HiveQL.
  • Big Data Technologies: Hadoop, Spark, HDFS, Hive, Cloudera, Hortonworks.
  • Cloud Platforms: AWS (Glue, Lambda, Redshift, S3, CloudWatch).
  • ETL / ELT Tools: AWS Glue, PySpark, Databricks.
  • Data Integration & Migration: Hadoop ecosystems, Kafka, real-time streaming, data lakes.
  • Data Modeling: dimensional models, structured and unstructured data processing.
  • CI/CD & Automation: GitHub Actions, Azure DevOps, Jenkins, Git, Autosys, Airflow.
  • Containerization & Orchestration: Kubernetes.
  • Experience in financial institutions or enterprise accounting environments.

EEO Employer. Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law.

Apex uses a virtual recruiter as part of the application process. Click here for more details.

If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Employee Services Department at [email protected] or 844-463-6178.

Everforth Apex is a world-class IT services company that serves thousands of clients across the globe. When you join Everforth Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing® in Talent Satisfaction in the United States and Great Place to Work® in the United Kingdom and Mexico. Everforth Apex uses a virtual recruiter as part of the application process. Click here for more details.

Everforth Apex Benefits Overview: Everforth Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Everforth Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Everforth Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6 months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Everforth Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Everforth Apex team member can provide.

Everforth Apex is a world-class IT services company that serves thousands of clients across the globe. When you join Everforth Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing® in Talent Satisfaction in the United States and Great Place to Work® in the United Kingdom and Mexico. Everforth Apex uses a virtual recruiter as part of the application process. Click here for more details.

Everforth Apex Benefits Overview: Everforth Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Everforth Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Everforth Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6 months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Everforth Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Everforth Apex team member can provide.

© 2026 Everforth, Inc. All rights reserved.

Everforth Apex Systems is part of the Commercial Segment of Everforth, Inc.

NYSE: EFOR

4400 Cox Road

Suite 200

Glen Allen, Virginia 23060

Everforth Apex is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Everforth Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law. If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Benefits Department at [email protected] or 804-523-8228. (Do not submit resumes or solicit consultants to this email address). UnitedHealthcare creates and publishes the Transparency in Coverage Machine-Readable Files on behalf of Everforth Apex.

Salary : $79 - $82

If your compensation planning software is too rigid to deploy winning incentive strategies, it’s time to find an adaptable solution. Compensation Planning
Enhance your organization's compensation strategy with salary data sets that HR and team managers can use to pay your staff right. Surveys & Data Sets

What is the career path for a Python / PySpark (Mainframe Modernization)?

Sign up to receive alerts about other jobs on the Python / PySpark (Mainframe Modernization) career path by checking the boxes next to the positions that interest you.
Income Estimation: 
$117,024 - $149,811
Income Estimation: 
$137,568 - $176,908
Income Estimation: 
$144,503 - $184,592
Income Estimation: 
$150,756 - $194,140
Income Estimation: 
$172,191 - $221,861
Income Estimation: 
$114,549 - $164,025
Income Estimation: 
$153,752 - $200,235
Employees: Get a Salary Increase
View Core, Job Family, and Industry Job Skills and Competency Data for more than 15,000 Job Titles Skills Library

Job openings at Apex Systems

  • Apex Systems Woonsocket, RI
  • Job#: 3033176 Job Description: Senior Product Manager, Pharma Analytics Contract to Hire Soho, NY (Hybrid 1-2 times a week) or Remote with travel to Soho S... more
  • 5 Days Ago

  • Apex Systems Providence, RI
  • Job#: 3033186 Job Description: Project Coordinator Location: REMOTE Employment Type: Contract Role Overview The Project Coordinator will support a large-sc... more
  • 5 Days Ago

  • Apex Systems Providence, RI
  • Job#: 3032764 Job Description: Senior Project Manager Location: REMOTE Employment Type: Contract Role Overview Our organization is undertaking a HIPAA reme... more
  • 5 Days Ago

  • Apex Systems Newark, DE
  • Job#: 3033331 Job Description: Application Architect III Location: Newark, Delaware (On-site) Employment Type: Contract Contract Duration: 12 Months Role O... more
  • 5 Days Ago


Not the job you're looking for? Here are some other Python / PySpark (Mainframe Modernization) jobs in the San Francisco, CA area that may be a better fit.

  • wellsfargo San Francisco, CA
  • Title: Senior Software Engineer - Python/PySpark Location : San Francisco, CA Duration: 24 months Work Engagement : W2 Work Schedule : 3 days in office/2 d... more
  • 12 Days Ago

  • Silicontek Inc South San Francisco, CA
  • Role – Senior AWS PySpark Developer Location – Hybrid – South San Francisco, CA We are seeking an experienced Sr. AWS PySpark Developer with 8 -10 years of... more
  • 15 Days Ago

AI Assistant is available now!

Feel free to start your new journey!