Stephen Geller

Stephen Geller

Full-Stack Software Engineer

Open to opportunities Part-time, contract, or 4-day week roles from early 2026. Based in Melbourne, open to remote/hybrid.

Key Achievements

Identity verification at scale Block
Developer tooling org-wide Guardian
E-commerce + content delivery Redbubble
Observability & SLO frameworks Multiple

From Psychology grad to scaling identity systems for millions at Block. 7+ years shipping products across backend, infrastructure, and frontend. Human-centered thinking meets technical depth.

Email me Download PDF LinkedIn GitHub

Experience

Software Engineer

Block (Cash App) May 2022 - November 2025

Led backend development for customer identity verification and support automation, serving millions of Cash App users globally.

KotlinMiskReactTypeScriptDynamoDBAWSDatadog
  • Verified millions of customer identities — Built Tap to Confirm system with in-app confirmation flows and multi-factor authentication
  • Drove org-wide SLO adoption — Created deployment drift monitors adopted across multiple teams, improving system reliability
  • Accelerated advocate workflows — Developed tools for PII verification, case management, and customer search
Show more details
  • Architected PIN-based verification, biometric authentication, and fallback mechanisms
  • Migrated customer data systems to CAPS, eliminating legacy dependencies
  • Mentored engineers through code reviews, pair programming, and technical guidance
  • Led incident response and post-mortem processes, improving system resilience

Software Engineer (Contract)

Cogent / Redbubble December 2021 - May 2022

Frontend engineer on Shop Experience team, delivering e-commerce features and content infrastructure improvements.

ReactTypeScriptNode.jsContentfulGraphQL
  • Enhanced e-commerce storefront — Built new landing page components driving improved user experience
  • Unified content delivery — Integrated frontend through BFF to Contentful CMS
  • Modernised tech stack — Upgraded Node versions and libraries across applications

Software Engineer

The Guardian August 2019 - August 2021

Focused on developer experience and observability improvements across the Guardian's digital department.

TypeScriptScalaAWS CDKGrafanaElasticsearchCypress
  • Centralised observability org-wide — Built metrics platform using Grafana, Elasticsearch and CloudWatch
  • Simplified AWS infrastructure — Created custom Guardian CDK library adopted across teams
  • Reduced production incidents — Built Cypress integration test service monitoring key user journeys
Show more details
  • Created chatbots integrating PagerDuty and GitHub events with Google Chat
  • Established mentorship program between the Guardian and Coding Black Females

DevOps Engineer

Lush Digital May 2019 - August 2019

Managed Kubernetes infrastructure and monitoring systems using Prometheus and Alertmanager.

KubernetesPrometheusAlertmanagerDocker

Software Developer

Unruly Media December 2017 - May 2019

Shared Infrastructure team member following XP and Agile practices for platform reliability.

JavaPythonAWSDockerJenkins
  • Maintained platform reliability — Managed shared infrastructure systems across the organisation
  • Reduced manual toil — Created tested, automated scripts for operations
Show more details
  • Led code dojos and workshops to upskill engineering teams

Skills & Technologies

Languages

TypeScript Kotlin JavaScript Ruby Python SQL

Frontend

React Next.js HTML/CSS Tailwind

Backend

Node.js Express Misk DynamoDB REST APIs GraphQL

Infrastructure & DevOps

AWS Kubernetes Docker Terraform CDK CI/CD

Observability

Datadog Grafana Prometheus Elasticsearch CloudWatch PagerDuty

Practices

TDD Pair Programming Agile XP

Education

Makers Academy

Software Development Bootcamp | 2017

Intensive 12-week bootcamp focused on TDD, pair programming, and Agile methodologies.

University of Sheffield

BSc Psychology (First Class Honours) | 2014 - 2017

Get in Touch

I'm always open to discussing new opportunities, interesting projects, or just having a chat about technology.

contact@geller.dev LinkedIn GitHub