Nicholas J. Arnold

Technical Leader | Distributed Systems Expert

About

Seasoned lead software engineer with nearly two decades of experience architecting and developing scalable, cloud-native distributed systems. Expertise in translating business requirements into robust technical solutions, leading engineering teams, and driving architectural excellence. Committed to building sustainable systems and fostering a culture of continuous improvement.

Relevant Experience
Principal Engineer & Owner — City Labs
Aug 2020  – Present
Denver, CO (remote)

City Labs is a contract software engineering and technical consulting firm that I own and operate.

Principle Software Engineer - APIs & Microservices (highlighted contract) — Arvest Bank
Sep 2021  – Mar 2024
Bentonville, AR (remote)

Contracted at the onset of an enterprise-wide multi-year digital transformation to lead the technical design and build-out of the foundation of Arvest Bank's new banking core services. Delivered the system that was chosen to serve the bank's commercial lending population. Advised and delivered across multiple teams.

Key Achievements:
  • Built an asynchronous central loan transaction processing system supporting multiple banking core systems enabling a gradual and seamless migration from legacy systems to Thought Machine's Vault core.
  • Designed and implemented a distributed tracing architecture with OpenTelemetry and Jaeger affording app and microservice teams a high degree of visibility into the flow of requests through APIs, Kafka topics and calls to persistent relational storage
  • Interviewed, onboarded, and provided technical oversight for multiple engineers across UI/UX and backend functions, growing the group from 2 engineers to 3 teams. Provided technical management of contract resources from three different contracting companies, coordinating their efforts, providing technical direction and reviewing deliverables.
Tech stack:
Java (17 -> 21), Spring Boot 3, Hibernate, Apache Kafka (later, Confluent Kafka), PostgreSQL (Cloud SQL), OpenTelemetry (tracing), Google Kubernetes Engine (GKE), Docker/Podman, OpenAPI, Terraform, Next.js, TypeScript
Technical Consultant (highlighted contract) — Good Move PT & Wellness
2024  – 2025
Denver, CO (remote)

Contracted to help a local physical therapy business with their website, digital marketing and backend process automation.

Key Achievements:
  • Automated superbill (PDF) creation for insurance reimbursement scenarios reducing weekly admin overhead time by 30%.
  • Created lightweight and secure documentation system integrated with medical coding standards (ICD-10-CM, CPT) saving the business from expensive commercially available solutions.
  • Developed an AI-assisted bizdev lead gen tool to scrape public information on business registrations related to health and wellness service providers resulting in a 150% time savings while greatly increasing referral source leads.
Tech stack:
Node.js, NocoDB (backed by PostgreSQL), Docker, nginx, Cloudflare, Counterscale (web analytics), Ollama (LLM-assisted text classification)
Principal Software Engineer — Pacific Premier Bank - Trust Division
Jun 2020  – Aug 2021
Denver, CO (hybrid)

Acquihired as part of Pacific Premier's acquisition of Opus Bank. Continued leading the technical development of both internal and public-facing services and integrations.

Key Achievements:
  • Lead a successful core platform migration from Innovest's InnoTrust to SEI's Digital Wealth Platform enabling the bank to realize a key strategic goal positioning themselves for future growth
  • Created comprehensive documentation of all microservices, events, and their interactions using Markdown and Mermaid.js leading to greatly improved system visibility, easier onboarding and more effective system extension
Tech stack:
JavaScript/TypeScript, Node.js, Angular, RabbitMQ, PostgreSQL, Docker, Kong (API Gateway), nginx, OpenAPI, Ansible
Principal Software Engineer — Opus Bank (acquired by Pacific Premier Bank)
Apr 2016  – Jun 2020
Denver, CO (hybrid)

Acquihired as part of Opus Bank's purchase of PENSCO Trust Company. Responsible for leading all technical development of the company's internal and public-facing APIs and microservices.

Key Achievements:
  • Designed, implemented and launched the Custodian Connect™ API allowing partner institutions to whitelabel our services providing the capability to open, fund and invest in alternative (non-publicly traded) assets
  • Simplified and secured the network architecture by introducing the Kong API Gateway to handle all incoming and outgoing traffic
  • Sole developer of a bulk account import capability used to onboard well in excess of $1 billion in assets and accounts from large new institutional partners
Tech stack:
JavaScript/TypeScript, Node.js, PostgreSQL, RabbitMQ, Docker, Kong (API Gateway), Ansible, Kubernetes, Helm
Senior Software Engineer — PENSCO Trust Company (acquired by Opus Bank)
Aug 2015  – Apr 2016
Denver, CO (hybrid)

Hired to help lead the greenfield development of a suite of cloud-native core services underpinning multiple newly-created internal and public-facing web apps.

Key Achievements:
  • Built a business-specific wrapper around the core trust accounting system greatly simplifying other internal and public facing service integrations. This service was also heavily leveraged by other future projects in the company.
  • Substantially increased developer efficiency by standardizing local development with Docker and Compose.
Tech stack:
JavaScript/TypeScript, Node.js, PostgreSQL, MongoDB, nginx, Docker
Software Engineer — Levels Beyond (acquired by Signiant)
Mar 2013  – Jul 2015
Denver, CO (onsite)

One of the first engineers hired after company received VC funding in late 2012. Initially was responsible for leading backend development of the bespoke codebase used by the UFC. Moved to the core engineering team as the company transitioned it's technology to a cloud-based service oriented architecture on AWS. Collaborated with exceptionally talented teams of engineers to build the technology that helped lead the company to a successful exit to Signiant.

Key Achievements:
  • Built the first version of the company's `Live Clipping` feature allowing a key early customer to monetize their content instantly versus waiting for up to 3 days for the digital masters to be shipped and imported
  • Increased new developer efficiency by ~25% via containerization and automation of our local development environments
Tech stack:
Java, Spring, ActiveMQ, Elasticsearch (now Elastic), Node.js, JavaScript, AWS (Cloudfront, EC2, Route53, S3), Github (git), Vagrant (containerization)
Assistant Research Engineer - Software Development — IIHR-Hydroscience & Engineering - The University of Iowa
Oct 2006  – Mar 2013
Iowa City, IA (hybrid)

Developed web-based tools, databases, and data models to process and visualize hydroscience data, supporting multiple NSF projects within a research team.

Key Achievements:
  • Directly supported the team’s acquisition of multiple NSF research grants.
  • Recognized for contributions to published research and presented team work at conferences.
  • Helped grow the software development arm of the team by interviewing and onboarding new members.
Tech stack:
Java, JavaScript, C# (.NET 3), PHP, SQL Server, MySQL, ArcGIS, Wordpress
Education