TDD

Upon joining, I came up to speed quickly on the stack of the early version of Pull Workbench, which was very buggy but demonstrated the initial ideas and had a solid set of the latest technologies and patterns established in the codebase, providing for a solid starting point.

I was entrusted to aid our CTO in hiring several additional employees, and so I joined and conducted interviews for the first several months while working with the existing team AI + Full Stack to deliver features and solidify the system, with the aim of keeping it fully working with each merge, after playing a little catch-up to fix the early bugs that worried our business partners, giving them confidence that our team could deliver.

From there, I developed full stack features solo or by pairing with team members, and ultimately led a squad of 5 team members alongside a second squad that together comprised our engineering team.

Much of my time went into authoring complex analytics sql queries using the impressive Kysely library, a fluent, typesafe query builder that we used for our postgres and redshift databases. Given the nature of the product, we needed to make decisions on which queries could be run in real time vs. which queries and subqueries would need to be computed offline as part of a network of airflow dags.

On the ML Ops side I advocated for traceability and reproducibility / determinism of all models and artifacts, and integrated with systems that implemented that, such as Airflow to coordinate DAGs of ML training jobs and Sagemaker's metadata API, which we controlled via model lifecycle automations that produced and stored models, artifacts and metadata that were in turn consumed at runtime or in batch by our analytics stack

On the frontend, I helped us deliver an initial version of the Pattern Editor, a UI and set of APIs that users could use to put together their own patterns of interest, such as looking for certain anomalous ranges of quantities that themselves may be derived from other user-defined patterns. This entailed not only a UI that was DAG-aware but also a layer that converted the json representation of these patterns from the frontend into typesafe kyesely queries to be executed against redshift.

The candidate summary page summarized a candidate's performance during multiple interview stages by presenting radar charts showing degree of fit against the values and attributes being evaluated for their position, as defined in the Interview Builder.

I built the frontend in React and Typescript, and integrated with the backend, which I partially built, which leveraged RAG and ran several Machine Learning models to produce scores and explainable AI. For example, models to break down interview transcripts into quotable fragments, evaluate relevance against configured company values, and call chatGPT APIs to obtain summaries and scores related to that content

Instead of splitting devops and infrastructure and tests completely separate from development teams, I moved the needle so that product development teams could own more of their own infrastructure and tests, creating less back-and-forth and empowering teams to deliver.

We used Devspace, which meant any dev or team could stand up a reproducible, isolated stack with multiple services and frontends running, in the cloud, as well as modify the definitions of the infrastructure and code themselves, directly, without permission or external team tickets.

This enabled product engineers to do more experimentation and testing thru declarative infrastructure and configuration management while still protecting our production environments, unlocking their shackles and potential as the experts in the software.

At the same time I worked to reduce the outsized role our amazing DevOps team was playing in the day to day management as well as enhancement of environments, which unfairly impeded expert developers by introducing red tape and inter-team processes that didn't add value.

I ran Appen's ML Platform, which was used by FAANG and many other startups and enterprises to automate and scale their ML practices, including running both supervised and unsupervised workloads, as well as their global annotation workforce which enabled customers to leverage our crowdsourced professionals to elastically obtain labelling and quality checking services for text, voice, image, video and LIDAR annotation, training and validation use cases.

I reported to the CTO and directed multiple full stack teams each with their own tech leads and range of engineering skills to do both regular maintenance and product enhancements using technologies like Sagemaker, React, K8s (Kubernetes), Spark, Kafka, Airflow, Spring(Boot), Ruby, Python, Java, Typescript and SQL.

Maintenance included regular updates to infrastructure, bug fixes, and performance optimizations across the platform. We migrated more and more services to K8s (Kubernetes) and Ambassador as our API gateway, where we could consolidate cross-cutting logic like auth and versioning.

Enhancements included changes to simplify the UX, kill redundant or unused features, add measurement to inform our choices, and larger efforts like Enterprise OAuth.

There were 4 different websites in different technologies, acquired from different companies, and some APIs, that all needed to be unified in terms of sign up, sign in, and sign out, given their existing state of each having separate user stores, including 3rd party vendor users who logged in with vendors and then authed to us with a hidden token.

It was a stalled project, so I started with missing requirements, incomplete designs and misleading progress indicators and focused other leaders and teams on delivery thru tested working software, focusing on tested user stories and on-the-ground learnings as units of progress, instead of large, outdated PRDs waterfall style.

Contributed directly in React / Typescript, Nodejs / express, Ruby on Rails and custom gems, OAuth configuration, Java Spring with runtime loaded SPI implementations from across separate applications domains.

There was a complex architecture at play and teams that did not know each other and weren't working as a single unit, so the landscape was difficult and rife with demoralized team members.

Although my team was to play but one part in many on the project, I realized quickly that there was no single leader or coherent plan, and so there was lots of blame game and treading water.

With permission from our VP of Engineering, I took charge of the teams and worked with product to firm up requirements, and replace the initially conceived solution architecture, which would not have worked and was created in a bit of a vacuum, into one that would actually work, by digging in and running all the services and web apps myself and understanding the multiple data stores and existing auth mechanisms including auth via 3rd party vendors to some parts of the system.

I delivered the project within 5 months and for my efforts was rewarded not long after with a promotion.

A working prototype and specs for how heartpoints would be rewarded and exchanged and linked to "Proof of Good" that could be validated off-chain (since proof of good in this case may for example, be video evidence or other data that is too large to fit onto the chain), using a strategy of hashing the proof and storing the hash and URL of the proof's off-chain content.

Observability was introduced to MapR via the Spyglass Project, which sought to obtain metrics from workloads as well as application specific metrics across all the tools and infrastructure of the MapR Hadoop Stack.

My responsibilities included automating the build and deployment of the full hadoop stack under development, automated test authoring and execution, mentoringjunior teammates to do the same, collaborating with dev teams to ensure they plugged into our CI/CD and Test framework nicely, andtroubleshooting problems that arose.

• Introduced Scrum process and Jira to the team
• Acted as scrum master in early days of project
• Developed automation to manage ESXI environments for CI/CD, involving heterogeneous MapR cluster installation, configuration and testing

With my experience at Progressive Insurance where I had learned to build my own code instrumentor for dynamic analysis, which I used alongside existing static analysis tools to test and measure deployed systems, I had a rich understanding of how to analyze runtimes of mobile apps, which was part of Lookout's mobile security backend special sauce.

With this mutual interest in mind I joined and helped create and standardize automated test suites as an engineer, developing libraries, frameworks and declarative jobs that constituted the types of tests needed to assure correctness and security of our own software offerings.

New Admin Dashboard - Architected and implemented green field admin dashboard, worked with junior devs and leadership to bring about in the requested stack: Bootstrap / JQuery / Ruby / Java / MySQL / LDAP. Users used Admin Dashboard to administer Organization, Role, and other management aspects of the Explorys EPM Suite.

Dependency Injection Framework - To enable high testability, all components required dependencies to be passed in, and so eliminating factory boilerplate without adopting a complex DI system was desirable. Wrote and shared a simple runtime-reflection based DI framework with multiple projects / teams

Temporal Sequencing - Architected, implemented and tested an enhancement to our proprietary Explorys MDL (measure definition language), which gave authors who use that language the ability to express dynamic temporal conditions as part of the predicate calculus that constitutes the measure being defined in a given MDL instance.

The solution runs in Hadoop as a mapper, where the MDL is parsed and a corresponding object graph is constructed, and then control is passed to the encapsulating object of that graph, resulting in a determination about the level of adherence of the given patient to the measure defined by the MDL which is then emitted for further processing.

The challenge here was authoring the solution without knowing the history or complexity of the existing system. The challenge was overcome by applying SOLID principles and TDD principles to express assumptions about the existing external system as interfaces, getting the solution to work in a test sandbox as a standalone application, and then once that was done, writing adapters between the actual system and the interfaces that were formerly mocked out for testing. The team which owned the system seemed impressed by and curious about the solution and the new patterns / tests involved.

By taking what had been considered a relatively tough problem, and, as an engineer with no history in the measure engine, applying an approach that allowed a fully tested solution to ultimately be plugged into the larger system very cleanly, as an implementation of a clear set of interfaces along the border of that system, I exposed the team to new patterns and solution design approaches that I hoped the team might take forward and build on as the system continued to evolve.

Example Use Case: Doctor wants measure of % of his/her patients having Hospitalization with outcome class X, where either 1 week later, Rehospitalization occurs or within 2 weeks, unexpected Office Appointment occurs. Doctor expresses using natural language oriented temporal sequencing expressions within model definition language.

The Quoting (F3) was a success, but to roll out to all 50 states, we needed an engine that could handle the complexity of the system, render quickly, and that was easier for our engineers to build and test with.

I took the most complex page of the Direct Auto Quoting app - the "Buy Page" - and drastically improved performance, reducing render time from 28 seconds to 2, by isolating the page and building it with a prototype of what would become REF2.

Seeing such a drastic improvement in performance gave the business the confidence they needed to convert Quoting (F3) to REF2 and use it to roll out to the remaining states. (sidenote: a code-oriented framework, FlashQuoting, which did away with REF2's markup and code bindings, superceded REF2 before all 50 states were rolled out. The later popularity of and similarities with React confirmed REF2 was onto something.)

Technical Details REF2 targeted both Flash and HTML during the pre-webkit era. Created technology-independent language and APIs for describing UI hierarchies, cascading styles, business logic and arbitrary data structures in a way that abstracted the developer away from the details of the client/server event communications, marshalling between multiple client technologies, persistence of state concerns, or the details of rendering engines / APIs in the various supported environments. Aided in development of dev tools such as code hinting and code generation to facilitate quick onboarding, compile time checks, type safety and debugging.

Having shown in Quoting (F3) and REF 2.0 (UI Framework) that tests and low complexity policies led to fewer bugs and higher velocity by doing some a/b studies, the business invested in tooling to automatically measure and enforce policies across the Direct Quoting line of business software development teams.

These teams used a variety of software stacks and technologies, including proprietary build and release systems.

I consulted with the build and release team, at the time, a separate team, to understand their plugin architecture which already was in use for all said teams.

Next, I worked with each team to understand their level of code coverage across different types of tests (unit, integration, end to end), and agree with them what targets they wanted to meet, and at what point in time.

Some teams required me to implement coverage measurement tools. Keep in mind that we were not able to use open source tech, and actionscript had no unit testing or code coverage tools.

I worked with a mentor of mine to write a lexer-parser-generator, which took the grammar for the actionscript language and allowed us to instrument our codebase with a pre-build step that inserted beacon calls with metadata into the various methods of the application. The coverage monitor and unit test UI was written in C#.

I exposed the coverage reporting service using web services running on SOAP via MS ASP.net WCF communications stack. Initially an MS SQL database housed the data, but as it grew, we moved it to a data cube where various dimensional summary and BI queries could be more efficiently run without interfering with the transactional nature of concurrent builds reporting their metrics in across the business.

Built upon existing code analysis and instrumentation tools to create a cross-platform solution for the build-time analysis of unit and system test code coverage, cyclomatic complexity, code coupling, defect density, change volume, maintainability, and other quality metrics. Data from many different proprietary formats is transformed into a single canonical format, where it is in turn normalized into a relational structure to facilitate on demand querying for system-level quality benchmarking, real-time code quality reporting, providing objective insight into QA risk assessments / test strategies, and enforcement of architectural standards and constraints.

Progressive had two sites for Direct Auto Quoting - one used by customers at home and the other used by our call-center reps. Given the complex state-by-state variance in the insurance laws, this made for a huge maintenance cost, and doing it twice in two codebases didn't make sense.

The premise was that a single web 2.0 Direct Quoting Application could replace these while also yielding a much more modern and customer-delighting application.

As the team's Actionscript expert, I joined and quickly helped out delivering feature after feature, and I loved the XP discipline and grew to appreciate TDD especially after the site started hitting performance problems that warranted significant refactors, which would have been much riskier without test coverage!

Our pilot included 14 of the 50 states, and was a complete success. However, the amount of clientside rules and assets started slowing the app down, and this was when I was asked to replace the REF framework that preceded my joining, with something much faster and more developer friendly. This led to my promotion to lead engineer, where I begun work on REF 2.0 (UI Framework)