Field CTO – Mainframe Modernization

Blitzy is a Cambridge, MA based AI software development platform on a mission to revolutionize the software development life cycle by autonomously building custom software to unlock the next industrial revolution. We're transforming how enterprises build software, turning enterprise requirements into enterprise grade code with an agentic software development platform that can autonomously execute 80% of the quantum of software development work. We're backed by multiple tier 1 investors, and have proven success as founders of previous start-ups.

Who we are

Led by two pioneering co-founders we are one of the fastest growing companies in the U.S., creating our own category of enterprise autonomous software development. We automate thousands of hours of software development for our customers, which includes strong representation within the Fortune 500.

How we work

- We move Blitzy Fast: Time is both our company’s and our clients’ most precious asset. We move quickly and decisively to innovate internally and deliver exceptional software externally.
- Championship Mindset: We operate like a professional sports team. We win as a team by holding ourselves and each other to high standards, collaborating in-person, and remaining focused on the mission.
- Passion for Invention: We’re pushing the frontier of what’s possible, requiring constant innovation and iteration.
- We Work for the Customer: We focus on delivering outsized value to the customers we work with and expanding those relationships into deep, meaningful partnerships.

About the Role

Blitzy is looking for an exceptional Field CTO with deep mainframe expertise to help solve one of enterprise technology’s hardest problems: making decades of mission-critical software understandable, transformable, and ultimately capable of continuous evolution.

Mainframes have earned their reputation for extraordinary reliability. Modernizing them responsibly requires much more than translating COBOL. It requires understanding and preserving the intricate relationships among business logic, data, transaction processing, concurrency, recovery, and operational behavior, while removing the architectural constraints that make change so difficult and expensive.

Blitzy already reverse-engineers and transforms complex enterprise software at extraordinary scale, including mainframe applications. Our platform has demonstrated the ability to understand codebases exceeding 30 million lines in days, and modernization programs are underway at Fortune 500 financial institutions.

Our ambition goes further. We want to progressively turn the hardest challenges of enterprise modernization into automated software capabilities, making each successive transformation faster, safer, and less dependent on scarce specialist expertise.

We are looking for someone who combines the depth of a world-class mainframe architect with the curiosity and imagination of a builder. Someone who respects why these systems work, understands where conventional modernization approaches fall short, and wants to help invent a fundamentally better way.

Compensation: $250,000-$350,000 + Bonus + Equity

Blitzy is an equal opportunity employer committed to building a diverse and inclusive team. We believe different perspectives make us stronger. Base salary ranges are determined by country, role, level, experience, and skills. The range displayed on each job posting reflects Blitzy’s good faith determination of the minimum and maximum targets for new hire salaries across all locations. Individual pay is determined by related factors, including job skills, experience, and relevant education or training, which may impact a final offer. Your Talent Partner can share more about the specific salary range during the hiring process

Responsibilities

Serve as a senior technical authority on mainframe systems, application and data architectures, transaction processing, and operational resilience.; Lead the architectural understanding of how application logic, data models, transaction boundaries, batch workloads, and runtime behavior interact across complex mainframe estates, ensuring modernization preserves system-level correctness rather than merely functional equivalence.; Work with customers’ most experienced architects to design target-state architectures that preserve business logic, concurrency, recovery, and operational guarantees.; Guide decisions about what to translate, rearchitect, or retain, minimizing migration risk and protecting operational continuity.; Partner with Blitzy’s engineering, product, partnerships, and sales teams to improve how the platform discovers, transforms, and validates complex applications.; Identify the most difficult and recurring challenges in mainframe modernization and work with engineering to turn their solutions into automated, reusable platform capabilities, progressively reducing the need for specialized human intervention.; Help extend Blitzy’s World Model to capture relationships among business logic, application behavior, data, and runtime dependencies, creating a richer foundation for automated transformation and validation.; Develop reusable validation approaches, reference architectures, and scalable service offerings, strengthen testing of functional equivalence, transactional integrity, and operational resilience.; Explore emerging AI and autonomous engineering approaches with curiosity and technical rigor, making each successive migration easier.; Build trusted relationships with CIOs, CTOs, engineering leaders, and senior mainframe specialists, communicating credibly at both architectural and executive levels.; Lead technical discovery, architecture reviews, workshops, proofs of concept, and technical validation for complex modernization opportunities.; Help customers articulate pragmatic long-term visions, connecting architecture choices to business outcomes, cost, risk, and strategic flexibility.; Work closely with Partnerships, Enterprise Sales, AI Solutions Consultants, and Customer Success to support customer decisions, adoption, and expansion.; Serve as a senior technical counterpart to cloud providers, global systems integrators, and specialist modernization partners.; Build relationships with partner CTOs, distinguished engineers, architects, and delivery leaders, establish confidence in Blitzy’s technical approach.; Co-design joint solutions, reference architectures, technical validation frameworks, and repeatable delivery methods partners can take to enterprise customers.; Support joint workshops and customer engagements, bringing implementation insights back into Blitzy’s product and service roadmap.; Help define Blitzy’s long-term technical vision for mainframe modernization, challenging conventional approaches and identifying opportunities to fundamentally change how complex enterprise systems are understood, transformed, and operated.; Contribute technical thought leadership through executive conversations, partner engagement, and selected industry forums.; Promote practical problem-solving, technical rigor, intellectual curiosity, and continuous learning.

Requirements

Deep, hands-on knowledge of IBM Z and z/OS, including technologies such as CICS, Db2, IMS, JCL, VSAM, Parallel Sysplex, RACF, MQ, and batch scheduling, with particular depth in several of these areas.; Demonstrated ability to reason about complex mainframe application behavior, data dependencies, transaction integrity, concurrency, recovery, and security—not simply COBOL syntax or hardware.; Strong understanding of modern distributed systems, cloud architectures, and enterprise modernization, including tradeoffs involved in translating mainframe behavior into modern environments.; Experience solving difficult technical problems in mission-critical enterprise systems and turning insights into practical modernization plans.; Ability to earn the confidence of experienced systems engineers and senior technology executives alike.; Passion for technology, customer outcomes, building better solutions, and learning about AI and autonomous software engineering.; Willingness to work hands-on with customer, partner, engineering, and product teams rather than acting solely as an external advisor.