Ben Flannery

Lead Software Engineer

Lexington, KY · Remote

Summary

Lead software engineer who owns large-scale backend and data platforms end to end, from architecture through delivery. Most recently replatformed AppOmni's identity data onto event-driven Go and Spanner, taking large-customer updates from weekly to minutes. Earlier work spans bank-wide authentication, security telemetry at billions of events a day, and connected hardware.

Experience

AppOmni — Lead Software Engineer

Sep 2022 – Present · Remote

  • Led the 9-month replatform of the Identity pillar, which unifies each customer's user accounts across their SaaS apps. Since its July 2026 launch, large customers' identities update within minutes instead of weekly, at 40M+ records for a single customer and billions of events a day.
  • Drove the architecture: event-driven ingestion in Go in place of a pull-based Celery chain inside the Django monolith, with in-place delta updates, periodic reconciliation, and a re-work queue. It is the first feature to span both the legacy and new data platforms, behind one interface; wrote the legacy publisher. Stale data from partial updates is gone, and measured drift is minimal.
  • Cut ingestion compute by over 95%, from 60–100 Celery workers at 2 CPU each to 4–12 autoscaled Go workers at 0.5 CPU, on a Spanner instance now shared across several features.
  • Shipped AppOmni's first APIs outside the monolith, a pattern other teams have since followed. The identity lookup service handles billions of enrichment requests a day, and AI/Agent Inventory was built on the platform, which the team is now extending to non-human identities.
  • Took over dynamic service scoring from a team that had stalled on it, led the design, and delivered it in 4 months. It scores every integration instance for every customer, recalculating as new data arrives, with VictoriaMetrics time series behind the dashboard APIs.
  • Co-founded the Architecture Guild with two other leads to connect siloed teams; the company's data replatform was conceived at a Guild offsite. Reworked the team's interview process, since adopted by 3 of 6 teams, and mentored engineers through promotion.

Fifth Third Bank

Apr 2020 – Sep 2022 · Remote

Principal Software Engineer

Jan 2022 – Sep 2022

  • Primary engineer on the authentication team that owned every consumer and commercial login at the bank, through the launch of its new mobile app. Led one of the two auth teams and shaped design across both.
  • Designed the login flow and built custom PingFederate integrations in front of the legacy mainframe customer account system (Java, Spring Boot).
  • Designed biometric login as a standalone service on AWS with its own integration.

Staff Software Engineer

Apr 2020 – Jan 2022

  • Built ingestion of full CrowdStrike Falcon telemetry from all 50,000+ bank endpoints into Elastic, about 5B events a day, for SOC analysts to query.
  • Built a YARA rule engine that runs analyst-owned rules against the full log stream and raises events to work, adding OS-level visibility (such as USB devices) and malware detection.
  • Built domain-threat monitoring: scanning registrations for squats (including punycode), similarity-hash fingerprinting of their content, header matching against past attacks, and sandboxed headless rendering so analysts could view payloads safely.
  • Helped design the replatform of the SOC's SIEM, ACE2.0 (later open sourced), from Flask on datacenter hardware to FastAPI with cloud hosting. Senior engineer on a team of 5–6; Python throughout.

Big Ass Fans — Senior Software Engineer

Sep 2015 – Apr 2020 · Lexington, KY

  • Represented Big Ass Fans in the Thread Group: vice-chair of the Commercial Working Group, co-authoring the IP-based secure commissioning proposal in the Thread 1.2 Commercial Extensions, and later a seat on the Board of Directors.
  • One of the primary developers of BAFCon, a touchscreen controller for industrial fans, on a team of four: chose the UI framework, architected the device model, and defined the Bluetooth API for over-the-air firmware updates. Management fast-tracked it and attached it to every premium product sale.
  • Built BAFCon Updates, the iOS app that updates BAFCon firmware over Bluetooth, as sole developer in two months, with multiple concurrent device updates.
  • Rebuilt the residential app with one other developer as i6 by BAF, the platform for next-generation residential products: Core Data model, protobuf API, account login, and Bluetooth onboarding. Wrote C/C++ firmware running on tens of thousands of devices.
  • Built the first automated iOS CI/CD pipeline on Jenkins: every pull request built and tested, failures reported to Slack and GitHub, tagged builds released to TestFlight. Until then, iOS builds ran on developer machines.

Skills

  • Languages: Go, Python, Java, Swift, Objective-C, C/C++
  • Backend & data: GCP, Spanner, Postgres, Parquet, Elastic, VictoriaMetrics, AWS, Django, FastAPI, Spring Boot, Celery
  • Security & protocols: PingFederate, CrowdStrike Falcon, YARA; Bluetooth and Thread protocol and API design
  • AI-assisted development: Claude Code agentic workflows with self-built tooling, since 2025