
Bill Martschenko
Verified Expert in Engineering
CTO and Developer
Morrisville, NC, United States
Toptal member since February 26, 2020
Bill is a veteran, hands-on CTO who presents quickly as a thought leader with executive presence. He can speak plain English to all sides of an organization, including investors and a BoD. His work includes seven startups. Add his fractional CTO and consulting roles, and his portfolio sits at 11 large enterprises and nine SMBs under $100M/year, covering digital transformation, disruptive innovation, rescuing technical debt, and explosive growth in both regulated and non-regulated industries.
Portfolio
Experience
- Thought Leadership - 20 years
- Cross-functional Collaboration - 20 years
- Leadership - 20 years
- Architecture - 20 years
- Startups - 20 years
- CTO - 18 years
- Digital Transformation - 9 years
- Objectives & Key Results (OKRs) - 3 years
Preferred Environment
Amazon Web Services (AWS), Pivotal Tracker, Slack, Visual Studio Code (VS Code), Linux, Google Cloud Platform (GCP), OS X, Agile Product Management, Objectives & Key Results (OKRs)
The most amazing...
...project I've led as a CTO is a data science startup to acquisition. We rebuilt the product line and I coded the ML from prototypes built by researchers.
Work Experience
Director of Product Engineering
Service Point Pro, LLC
- Stabilized a seed-stage field service management platform unable to release due to systemic quality failures and compounding production defects.
- Established a dedicated hardening program, increasing module test coverage across all 25 core modules to medium/large coverage and elevating 8 critical user journeys to large coverage.
- Accelerated bug resolution velocity by 2x and QA automation throughput by 3x through AI-assisted test generation, structured specifications, and refactoring workflows.
- Introduced AI-first (AI1) engineering doctrine; achieved 2–5x developer acceleration via Claude Code, multi-agent orchestration, and structured spec-to-test pipelines.
- Directed AI-enabled engineering tooling stack (.NET 8 APIs, Python/Django AI services, React/React Native, PostgreSQL, Pinecone, ClickHouse) to support RAG pipelines, NL-to-SQL, vectorized search, and forecasting workflows.
- Implemented PERT-based estimation and dev-day capacity modeling to replace unrealistic waterfall timelines; delivered a 12-week hardening roadmap in 11 weeks under incremental delivery.
- Reduced release instability by introducing unit testing discipline, automated regression coverage, and structured weekly executive roadmaps generated via AI.
- Trained engineering staff in AI-assisted development (Claude Code, Cursor, and wshobson/agents framework), enabling non-SMEs to generate structured specs, tests, and bug triage workflows.
- Introduced and reinforced foundational engineering leadership practices: weekly 1:1s, QA standards, coverage tracking, roadmap transparency, and investor-facing delivery reporting.
CTO Executive Coach
Pediatric Emergency Standards, Inc.
- Engaged in a 2-month executive rescue to elevate a founder-backed CTO who had reached a leadership and delegation ceiling.
- Diagnosed breakdown across the delegation channel: micromanagement, unclear enduring responsibilities, and inability to translate technical execution into executive results.
- Introduced AI1 doctrine (AI-first if >15 minutes of thought) and embedded Claude Code into leadership and sprint workflows.
- Built a custom AI product owner agent used live by the CTO, CEO, and chief medical officer to analyze Jira sprint history and benchmark against industry best practices.
- Demonstrated how role-specific AI agents provide expert-level analysis and bridge cross-functional understanding gaps.
- Advised rebuild of sprint structure (hundreds of points across a small team) into simplified, autonomy-driven commitments.
- Implemented structured delegation syntax, converting CTO intent into machine-parseable weekly deliverables.
- Instituted weekly executive cadence tied to enduring CTO responsibilities and time-boxed strategic initiatives.
- Applied the pyramid principle training to shift the CTO toward result-first executive communication.
- Contributed to the outcome: restored executive confidence in CTO, materially improved CEO–CTO alignment, and embedded AI into leadership decision-making.
Fractional CTO | Executive Coach
BlackWave LLC.
- Restructured a product relaunch that was 6 months behind schedule, delivering the launch within 3 months of engagement.
- Reduced delivery lag by around 50% through AI-enabled planning workflows and vendor decoupling.
- Identified root causes of technical debt driven by ineffective outsourcing; transitioned third-party engineering to legacy-only support.
- Introduced Claude Code as an executive tool, enabling a non-technical CEO to rebuild UX direction independently and eliminate vendor dependency.
- Shifted product strategy from feature-driven debate to revenue-anchored customer acquisition targets; aligned all development priorities to measurable ROI milestones.
- Implemented the RACI framework to clarify accountability across leadership and engineering.
- Replaced recurring 2-hour unfocused all-hands meetings with short, time-boxed executive cadence meetings tied to weekly deliverables.
- Coached the first-time CEO on directive leadership, stakeholder management, and managing dominant personalities impacting execution velocity.
Fractional CTO
Sema Technologies, Inc
- Completed SOC 2 Type II certification with a third-party auditor, providing evidence of authorized production releases and disaster recovery procedures.
- Trained a Claude-based AI agent as a SOC 2 Type II SME to answer security due diligence questionnaires using internal SOC 2 policies.
- Designed 60% AWS cost reduction in 2 phases (40% immediate and 20% long-term) on a 10,000+ line item bill, with total costs growing 30-50% monthly.
- Trained 3 AI staff for communication tasks: summarizing transcripts, coaching CEO communication, and generating weekly executive team summaries.
- Trained 2 AI staff as engineering management SMEs for 2 teams by ingesting Slack logs, Jira roadmaps, sprint plans, docs, and backlogs.
- Trained AI staff to generate after-action reports from Slack logs, extracting staff involved, customer impact, resolution time, and effects on upcoming software releases.
- Managed 3 teams: core product for source code analysis, new AI integration team, and LLMOps research team focused on pipelines and prompt engineering.
Products and Technology Architecture Strategist
Hearst - Technology
- Designed a repeatable evaluation process for the CTO to assess subsidiary profitability and technical relevance via online collaboration, questionnaires, and interviews.
- Trained an AI to help author technical questionnaires on architecture, generative AI, telemetry, data, security, compliance, business continuity, deployment, monitoring, and onboarding.
- Devised a Microsoft Teams hub to orchestrate collaboration and host data rooms for hundreds of subsidiaries.
Architect | Tech Lead
Neutron Engineering LLC
- Led R&D and prototyping of a mobile web dashboard deployed in mobile hardware (Pelican case) housing sensors and TBs of storage using Docker Compose, SolidJS, TimescaleDB (PostgreSQL), GraphQL, and REST APIs over Hasura, Telegraf, and MQTT.
- Designed large-scale architecture for a 100% peer-to-peer network of thousands of Pelican cases worldwide, sharing data from its sensors with the rest of the network and receiving data from the rest of the peers.
- Applied human-guided GenAI to accelerate scaffolding of GraphQL schema design, containerized services, D3.js visualizations, and web3 p2p networking.
- Leveraged the libp2p library from the Web3 initiatives for large-scale peer-to-peer discovery, publish/subscribe over gossip protocol, and a distributed hash table.
- Created two successful showcases for the client's client. The 1st delivered functional components instead of just a PowerPoint, while the 2nd, completed in two weeks, impressed them with progress that felt like months of effort.
- Used Amazon WorkSpaces to build a secure, reproducible lab environment with multiple machines. Docker Compose encapsulated front-end and back-end services, ETL pipelines, and applications, all thoroughly documented for easy replication.
- Managed technology stack and implementation spanning the front and back end.
Fractional CTO
Beca - Main
- Worked with a client, and after eight months, they expressed satisfaction by buying the rights from Toptal to engage me directly outside the Toptal platform.
- Helped attract ongoing funding from the parent company by co-authoring an evolving value proposition as the product emerged from the prototype.
- Built, using Python and Volttron, the architecture, prototype, and 1st implementation, serving as the product owner and software CTO who paired with the building engineering side CTO.
- Embedded on a Raspberry Pi Edge Box at each client site and scaled software using green threading and distributed computing principles to allow 100s of 1000s of separate computational automata to manage the building sensors such as HVAC equipment.
- Designed a data lake schema to the scale of TBs/PBs per year per customer for operational and computational transcripts at each Edge Box. Implemented the data stream per this schema to enable operations and data science teams.
- Built, using Jupyter Notebooks, an analytical bridge to the product and its data lake of operational transcripts to calculate cost and energy savings. A day of data could be emulated in seconds to explore new controller logic.
- Saved project staffing resources by building a DSL that enabled less costly SMEs, such as building engineers and mechanical engineers, to author building-specific controllers rather than growing an expensive team of software engineers to hand code.
Fractional CTO
Perpetuating
- Advised on technology readiness, leadership, product, and architecture for a candidate tech company seeking growth funding for an investor (Perpetuating's CEO).
- Interviewed principals in the candidate tech company and reviewed technology documentation and plans.
- Built a detailed report card with recommendations, including where the real work is getting done and who the actual thought leaders and implementation leaders were.
CTO
AddShoppers
- Served as their CTO, and at seven months, the client expressed satisfaction by buying rights from Toptal to engage me directly outside the Toptal platform.
- Grew the engineering team five-fold, from 4 to 20, in ten months, including two acquisitions that resulted in staff spanning time zones from West to East: Hawaii, mainland US, Poland, Bosnia, UAE, Pakistan, and India.
- Led the rebranding and relaunch of an acquired consumer-facing product, a Chrome extension, in 1.5 months from the acquisition point.
- Built, using Python and BigQuery, a continuous pump of data to a data lake in GCP for in-house reporting that combined data from MongoDB and 3rd-party vendors such as SparkPost.
- Led and co-wrote a data lake-based infrastructure to increase capacity from 0.1 PB per month to 10 PB per month using an approach that would scale to PBs per day and millions of events per hour.
- Transitioned from partial Kanban to a Scrum practice, hiring both a product owner and scrum master as the company grew four times, from nine to 40, in ten months.
- Led a Go POC using different graph databases (RedisGraph, Neo4j, dgraph.io) to implement an identity graph to process millions of events per hour and house 500 million nodes and 100+ million edges.
- Led and coded a Go project to build a gaming abstraction called SpyNet to represent the in-house systems' basic architecture to educate staff better and facilitate interviews.
- Coded a Go POC for improving 30x a customer ingestion pipeline that reduced 150 minutes per customer to at most five minutes per customer.
CTO
InHerSight
- Led the architecture and build of data pipelines on AWS/Heroku infrastructure (S3, EC2, Lambda, Gateway, CloudWatch, EC2, Python scripting) for processing user activity analytics and user engagement via email.
- Oversaw the architecture and product implementation for web, mobile, and large-scale outbound email campaigns using Django, React Native, and SendGrid.
- Built, in Python, a continuous pump of data to a warehouse for in-house reporting, combining data sources from SendGrid and an application database.
- Spearheaded the transition from partial Kanban to a Scrum process to drive an expectation-of-excellence culture, including innovation from anyone and weekly accountability to the CEO in business terms.
- Refactored, for performance and scale, an MVP website that was more than 30 seconds per page, and sometimes timing out to sub-second.
- Built detailed monitoring of all website activity into a data stream fed into a warehouse for analyzing the success of user campaigns.
- Optimized data ingest by configuring PostgreSQL on AWS to receive append-only, bulk data writes from 3rd-party APIs and provided background Python batch scripting to clean and aggregate into a data warehouse.
- Evolved a company vocabulary for analytics based on incremental needs for analytics from the business analysts and wrote data pipelines in Python and SQL.
CTO
Bivarus
- Spearheaded the buildout of a data-centric platform scalable to millions of monthly inbound customer transactions.
- Built a team across two US offices and with some staff in Ukraine.
- Refactored a low-throughput MVP via a decentralized service bus using RabbitMQ.
- Led the architecture and build of data pipelines on AWS infrastructure (S3, EC2, Lambda, Gateway, CloudWatch, EC2) for continuous data feeds used per client custom transforms.
- Led the complete rebuild of the UX following a customer-driven story approach.
- Hand-coded the machine learning algorithms in Python for at-scale performance based on MATLAB prototypes built by university data science researchers.
- Organized companywide effort to define the business vocabulary and models for dashboarding and then built a warehouse (Sisense) using data pipelines.
- Innovated a self-correcting data pipeline using Spotify's Luigi open-source platform to auto-fix downstream calculations and dashboards when clients issued corrections to their historical data.
- Built a robust EHR integration pipeline of HL7 and non-HL7 data using iNTERFACEWARE Iguana, which offered field mapping and custom, per-client transformations using the Lua programming language.
- Integrated a chatbot (NarrativeDX, also acquired by Press Ganey) to provide human discussion and narration of data and data science projections.
CTO Advisor
Integrify
- Prototyped a major technology change to MongoDB from the SQL server for an existing web property that is available on-premise and in the cloud.
- Performed a substantial ETL analysis to quantify, transform, and clean both data and schema.
- Paired with the CTO to investigate the value of replacing licensed databases (SQL Server, Oracle) and a licensed operating system (Windows) with Linux and MongoDB.
Vice President of Engineering | Chief Architect
VIPER
- Transformed an early SaaS prototype into one serving 80 customers worldwide, scaling to tens to hundreds to thousands of seats each.
- Built a virtual team in the US, Brazil, and Russia and instilled Scrum practices.
- Instilled an expectation-of-excellence culture, including accountability to the CEO in business terms, quality control, DevOps, push-button deployments, and software that monitors its own health.
- Implemented compiler algorithms to code generate a high-performance, customer-specific financial solver.
- Built a near real-time dashboard with 100,000 numbers behind a single KPI.
- Automated data-rich activity transcripts per user to improve customer support, license tracking, and insights beyond Google Analytics.
Data Architect | National Standards Committee
AGC of America
- Worked directly with a board of industry executives and led online workgroups of their subject matter experts in the US and UK to model business processes and data.
- Wrote position papers and Excel dashboards to monitor a highly technical process.
- Authored all technical artifacts including modular workflow patterns in UML and BPM&N.
- Served as the scrum-of-scrum master for a multi-vendor integration and helped present it at a national convention in Las Vegas.
- Built a custom, continuous integration server to intercept network traffic, validate, correct, capture timings, and post scrum milestones online.
Experience
Data Architecture for a National Standards Committee
Role: Data Architect
Tasks Accomplished:
• Worked directly with a board of industry executives and led online workgroups of their subject matter experts in the US and UK to model business processes and data.
• Improved the schedule and credibility by researching and following an established methodology.
• Wrote position papers and Excel dashboards to monitor a highly technical process.
• Authored all technical artifacts, including modular workflow patterns in UML and BPM&N.
• Served as the Scrum-of-Scrum Master for a multi-vendor integration and helped present it at a national convention.
• Built a continuous integration server to intercept network traffic, validate, correct, capture timings, and post scrum milestones online.
Accelerating a Startup to the First Funding
I led the completion of an MVP to be used for the first round of funding using Python and FastAPI, PostgreSQL, ChatGPT-4, Google Cloud Platform (GCP), and potentially Bubble. I also provided advice on dealings with an underperforming third-party software vendor. We prototyped the use of the ChatGPT API via GCP so that travelers could engage with itinerary planning and general exploration of destinations.
Education
Master's Degree in Computer Science
Georgia Institute of Technology - Atlanta, GA, USA
Bachelor's Degree in Mathematical Sciences
University of North Carolina at Chapel Hill - Chapel Hill, NC, USA
Skills
Libraries/APIs
React, Node.js, REST APIs, Python Asyncio, Asyncio, SQLAlchemy, SendGrid API, Vue, jQuery, D3.js, SolidJS, Libp2p
Tools
Slack, Pivotal Tracker, Jupyter, Docker Compose, Claude Code, Git, Celery, GitHub, IntelliJ IDEA, Postman, Aha!, BigQuery, GitLab, RabbitMQ, Grafana, Jira, Confluence, ChatGPT, Bubble, Amazon WorkSpaces, MQTT, Telegraf, Microsoft Teams, Microsoft Copilot, Amazon CloudWatch, Terraform, Claude, Retool, Cordova Plugins, Capacitor
Languages
XSD, Web Services Description Language (WSDL), XSLT, HTML, Python, C#, C++, C, JavaScript, SQL, CSS, Python 3, C#.NET, Ruby, GraphQL, TypeScript, PHP, XML, JADE, Go, R, Domain-specific Languages (DSLs), Cypher, Lua
Frameworks
.NET, Ruby on Rails (RoR), Flask, JSON Web Tokens (JWT), OAuth 2, Next.js, Bootstrap, Django, React Native, Angular, Laravel, Django REST Framework, NestJS, Ionic, LangGraph
Paradigms
Event-driven Programming, RESTful Development, Agile, Microservices, Scrum, Agile Product Management, Continuous Integration (CI), ETL, Objectives & Key Results (OKRs), Continuous Delivery (CD), Unit Testing, Microservices Architecture, Desktop App Development, HIPAA Compliance, DevOps, Business Process Modeling Notation (BPMN), B2B, B2C, Mobile Development, REST, E2E Testing
Platforms
Docker, OS X, Amazon Web Services (AWS), Visual Studio Code (VS Code), AWS Lambda, Google Cloud Platform (GCP), Linux, RStudio, Windows, Heroku, Azure, Mobile, Algolia, Kubernetes, Raspberry Pi, iOS, Firebase
Storage
JSON, Relational Databases, MySQL, PostgreSQL, SQL Performance, Databases, MongoDB, NoSQL, Redis, Data Pipelines, Microsoft SQL Server, Data Lakes, Elasticsearch, Google Cloud, Hasura, Amazon Aurora, ClickHouse
Industry Expertise
Healthcare, Project Management
Other
Architecture, RESTful Web Services, Code Architecture, Data, Data Engineering, APIs, CTO, Scrum Product Owner, Digital Transformation, Startups, Technical Project Management, Leadership, Technical Architecture, Full-stack, Software Architecture, Back-end, API Integration, Technical Leadership, Cloud, Data Modeling, Cross-functional Collaboration, Thought Leadership, Hands-on Implementation, Team Leadership, AWS DevOps, Multithreading, Code Review, Concurrency, Software as a Service (SaaS), Multiprocessing, Distributed Systems, Fractional CTO, Startup Funding, Technology, Anthropic, Queue Management, RESTFul APIs, Back-end Development, Software Development Lifecycle (SDLC), Full-stack Development, Healthcare Software, System Architecture Design, Web Development, Executive Leadership, Information Technology, Platform as a Service (PaaS), Software Design, Cloud Infrastructure, Integration, Communication, Solution Architecture, Automation, IT Strategy, Software Integration, Software Development Lifecycle (SDLC), Technical Project Management, Linux, Open Source, Scalable Platforms, CTO, Stakeholder Management, Project Planning, Generative Pre-trained Transformer 4 (GPT-4), Opus, Sonnet, Information Architecture (IA), Pub/Sub, SaaS, Time Series, Internet of Things (IoT), FastAPI, HVAC, Industrial Internet of Things (IIoT), TimescaleDB, Front-end, ChatGPT API, Artificial Intelligence (AI), Large Language Models (LLMs), Electronic Health Records (EHR), HL7, Mobile Apps, Compliance, AI Agents, HIPAA Electronic Data Interchange (EDI), Electronic Medical Records (EMR), ETL Pipelines, Sensor Data, AI Consulting, IT Infrastructure, Data Governance, Business Transformation, Artificial Intelligence (AI), AI Integration, Data Science, GraphDB, Chrome Extensions, eCommerce, Machine Learning, Serverless, Energy Monitoring, Energy Management, Scripting, Timescale, VOLTTRON, Enterprise SaaS, Software, Software Development, Venture Capital, Venture Funding, Fundraising, Chatbots, CI/CD Pipelines, Azure Event Grid, Redis Streams, Embedded Python, Low Code, R&D, Peer-to-peer Networking, Maps, Solid Start, Pelican Case, Web Dashboards, Strategy, New Products, Data Rooms, AWS Cost Optimization, SOC 2, Temporal, Generative Artificial Intelligence (GenAI), Executive Coaching, Technical Debt Remediation, Product Strategy, RACI, Vendor Management, UX Strategy, Revenue-Driven Product Planning, Delivery, Mobile App Development, Cordova, Google BigQuery, AI Enablement, Cross-functional Team Leadership, Product Management, OpenAI, Groq, RAG Architecture, Pinecone, User Journeys, PERT Estimation, Agile Transformation, Engineering Turnarounds, Cursor AI
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