Software Engineer Senior

Steven Heller

SAN FRANCISCO,CA 510-***-**** ********@*****.*** linkedin.com/in/steven-heller-31300b1/

Senior Software Engineer

Solution Architect / Senior Integration Specialist / API Design, Integration & Development

Experienced Senior Software Engineer and Solution Architect with a track record of leveraging extensive technical proficiency, process expertise, and leadership insight to conceptualize, execute, integrate, and maintain software solutions. Proficient in guiding internal, customer, and partner engineering teams, fostering a unified vision across diverse functions, prioritizing customer-centric objectives, and ensuring transparent communication of project status and updates. Known for pragmatic problem-solving, collaborating within high-performing teams, and delivering tangible results through streamlined processes and innovative software solutions. Adept at driving efficiencies, accelerating delivery timelines, and executing value-driven strategies to achieve overarching goals. Recognized as an empowering leader capable of orchestrating all project phases and optimizing performance to align with broader business objectives.

Core Competencies

Protocols: CGI, HTTP, TCP/IP, Ethernet, Networking, XML, WS-Security, PAM, LDAP, SQL, Perl XSubs, Pandas/ML

Languages: C#, Java, C++, HTML,VB6, Bourne/C Shell, Perl, PHP, Pascal, Forth/Fortran/Basic/Assembly, Ruby, Python

Platforms: Windows, UNIX/Linux, Embedded Systems, MFC/Win32/COM/.NET, Oracle/Postgres/DB2/SQL Server

Skills: Object Oriented Design/Architecture, Multi-Threading, PKI, Strong Auth, Database, J2EE, JUnit, AWS,

Credit Card Payment Processing, Backend Server side & Database, API & SDK Development, Machine Learning

Other: French, Spanish, German. Familiar with Japanese, Mandarin, Cantonese. LLM/AI familiarity.

Accomplishments

Constructed full deployment process and supporting guidance, samples and documentation for Select, a new product which recovers lost revenue for merchants, collaborated with merchant customers to pioneer the Select launch with several large customers and within 8 months revenues were restored and new clients were acquired regularly.

Pioneered complete deployment process at Vindicia and collaborated with merchants on the initial rollout of a new product select, Retain, to recover up to 20% of failed transactions previously written off and saved the subscription from default cancellation to preserve the average customer lifetime value of ~18 months and the product became the central revenue generator and achieved 60% of the company revenue compared to the original billing system.

Led a PPI team through the transition from the original Dialect gateway to the new V2 payment gateway with the acquisition of Paradata and provided technical expertise to advise on the new gateway and needed features, which led to the acquisition and the ability to deploy new merchants on the V2 gateway without the extra costs and delays.

Constructed libraries at PPI for Pin Pads (Verifone 1000SE, Ingenico i3070/i6550) for U.S. & Canadian pin debit integrations to PayMover, in COM/VB6 & .NET, using direct Serial interface protocol and OPOS ActiveX controls.

Developed Payflow Pro SDK clients in C, Java, Perl (Xsubs), and PHP on Windows and Unix platforms (Linux, FreeBSD, AIX, etc.) for e-commerce payment clients accessing payment server, installed base of 150,000+ merchants.

Merged all code bases to one for each language and platform and ensured a single build of one code base and build system runs on each platform to build all Libraries at one time and deliver to Q.A. from the same source, allowing the ability to handle escalations quickly, and reduced the need to many escalations as the Support Team was able to resolve directly with meaningful error messages at the same time.

Experience

The Build Fellowship by Open Avenues 2024 Oct - Dec

Machine Learning Pipeline Build Student Consultant

Working with sports video, input frames where the ball is in play, used it to train various model classifiers, and used it to predict ball active status using multiple features, such as sudden change in direction. Finally write out only those frames active to shorten the viewing time.

Used scikit-learn with RandomForestClassifier and others to determine best success rates. https://github.com/szheller/ML-Pipeline-Video

Ongoing Training 2024 - Present

Continuing Education / Machine Learning (ML)

Advancing my skills with Machine Learning (ML), and Large Language Models (LLM) for the

current Artificial Intelligence (AI) demand.

Steven Heller Page 2

Experience Cont.

Vindicia, Inc. San Mateo/San Francisco, CA 2010 - 2023

Deployment Consultant, Solution Architect

Guided merchants to assist in the integrations to the subscription billing system, advised on the design and implementation of use cases to meet launch and revenue targets and wrote many use cases for API implementations.

Collaborated with payment processors and advised merchants on setting up Paymentech, Litle/Vantiv/WorldPay, CyberSource, First Data, Authorize.net, PayPal, Braintree, Payway, Stripe, and others.

Conducted presentations for launch kickoffs, to executive, project management, operations, & finance audiences.

Supported other teams and operations and maintained repeatable processesand template tickets with complete steps to make the processes repeatable and trackable across many merchants.

Engaged partners in developing integrations to be re-used and onboard their complete portfolio of merchants to the Retain product while maintaining their existing billing system.

Generated and implemented repeatable processes for deployments with partners, including CDS Global, Naviga, Omeda, Newzware, and Recurly, to be manageable for ongoing support.

Onboarded at Vindicia, a startup, and remained with the company through an initial downturn and subsequent recovery coinciding with the rollout of the product Select, and the company thrived upon Amdocs 2016 acquisition.

Committed to staying with the newly formed Vindicia, a subsidiary of Amdocs, and provided Select's primary source of product knowledge and value to different key stakeholders as larger enterprise merchants were deployed.

Payment Processing Incorporated Newark, CA 2005 - 2010

Director of Development, Senior Integration Specialist

Authored SQL queries for the MS SQL Server for gateway operations during the transition

Assisted client partners with the integration of their point of sale (POS) application to the PPI PayMover gateway, achieving integrated credit card processing in their POS.

Supported the development & test plans, resolved escalated development challenges, with the PayMover libraries in COM/VB6, .NET, Java, Perl, PHP, Cold Fusion and Direct HTTP Post, and completed the final certification of the integration with production interchange transactions.

Utilized POS to integrate the PPI payment gateway with partners referring merchant accounts for recurring revenue.

Updated the IBM WebSphere Payment Manager Cassette in Java to use the new encryption key required by the new version of WebSphere, which required reverse engineering of the WebSphere framework.

Developed libraries for Pin Pads (Verifone 1000SE, Ingenico i3070/i6550) for both U.S. & Canadian Pin Debit integrations to PayMover, in COM/VB6 & .NET, using both direct Serial interface protocol and OPOS ActiveX controls. Supported USB/Serial installations of the Pin Pad libraries in Remote Desktop / Thin Client environments on Windows Server 2003 / 2008. Ultimately wrote instructions w/complete steps & data cable termination as

required & all Wyse Thin Client serial configuration settings & used by Installation Team to systematically succeed.

Developed integration libraries that incorporated built-in timeout handling and error logging and automatically incorporated the correct interchange parameters. Used an object-oriented design that factored in common transaction handling and implemented a consistent interface and similar data type in .NET and COM/VB6.

Served in compliance services, assisted client partners in having their POS PA-DSS validated using a Qualified Security Assessor/QSA,& Level 1 PCI validations for service providers for the Visa mandate for PCI compliance.

Involved in reviewing SQL database schemas & cardholder dataflow diagrams; the process is required for merchants & service providers to process credit cards following the mandate and reduce liability in case of a card data breach.

Steven Heller Page 3

Experience Cont.

VeriSign, Inc. Mountain View, CA 1999 – 2005

Senior Software Engineer

Implemented the company's first all-Java PayflowPro Client and developed payment integrations (IBM WebSphere, ColdFusion MX, Microsoft Commerce Server, Oracle iPayment) with SQL to IBM DB2, Microsoft SQL Server, and Oracle databases.

Cultivated version tracking of payment clients and wrote, maintained, and ran SQL queries weekly to compile usage reports by SDK platform, client, or integration.

Developed XMLPay API in Java as part of the Trust Services Integration Toolkit, which used DOM parsers to generate and parse XML and issue payment transactions to the payment server.

Designed and wrote a Java library to perform certificate lifecycle operations by communicating with the VeriSign-hosted certificate backend engine and enterprise-hosted services to securely issue PKI certificates and maintain key material from a trusted source.

Fabricated the security server as part of a Jetty/J2EE platform team and implemented the service connector used to perform certificate enrollment at the customer site.

Devised the JMS service connector and developed support for hardware security module storage of private key material fora secure installation using a nCipher HSM.

Served as the technical lead for the transition of payment integration projects to the Offshore Development Center.

Contributed to the specification of the new standard HTTP protocol, which is now used by the Payment Server.

Implemented the V4 Payflow Pro SDK in Java, which uses the new protocol and a state-driven architecture.

Selected to the Unified Authentication Team, designed and developed authentication clients, which provided strong second-factor authentication using a one-time password algorithm and hardware tokens.

Launched the PAM (Pluggable Authentication Method) authentication module for OTP authentication support and integrated it with SSH servers (OpenSSH, F-Secure), Telnet and FTP,and LDAP authentication on Linux and Solaris.

Originated the IBM Tivoli AccessManager/WebSEAL plugin (CDAS) and the Oblix NetPoint Access Server plugin for OTP authentication.

Maintained token management utility in Java, which enrolled tokens in preparation for OTP authentication and added support for HSM's nCipher and Luna SA for authentication as the registration authority.

Developed a validation server test harness using Java and JUnit with Ant to drive automatic testing in Q.A., to access LDAP servers, or any database using JDBC/ODBC, and to issue OTP authentication requests using the correct next OTP value for the current OTP count from configured test script commands, using SQL statements.

Geoworks Corporation Alameda, CA 1998 - 1999

Server Design Engineer

Design of Wireless Internet Web Server providing multiple transport (HTTP, SMTP/POP3, SMS, WAP, etc.) and handphone/device access in C++ under Solaris, using Apache, Oracle Database and Rogue Wave DBTools.

Dionex, Corporation Sunnyvale, CA 1995 – 1998

Senior Software Engineer

Software dev in Visual C++/MFC under Windows95 of client/server app over LAN to proprietary modules.

Areas of development included Lan Driver and proprietary protocol under both Windows95 and Windows NT, and Win32 multi-threaded development for the application.

Supervised device driver development of NDIS protocol driver to for standard LAN cards under Windows95 & NT.

Octel Communications Corporation Milpitas, CA 1994 – 1996

Windows NT Software Engineer

Developed specification and implementation for API to access Voice Server under NT, using dll, thread allocation and synchronization under Win32. Worked under Microsoft Visual C++/MFC environment on client/server application. Provided design input and specification for the voice mail system interface.

Education & Training

B.S. Electrical Engineering and Computer Science University of California Berkeley, CA

Member, Eta Kappa Nu Electrical Engineering Honor Society

TCP/IP, UNIX Network Programming, NT/Win32, MFC/VC++ UC Extension Santa Clara, CA

Stanford University Palo Alto, CA

C++/Object-Oriented Design, Database System Principles, Distributed Databases, Transaction Processing

City College of San Francisco San Francisco, CA

Data Science using Python

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