Egill Erlendsson

• Designed, maintained and evolved backend systems supporting live auctions, financial workflows, invoicing, settlements, reporting and operational administration.
• Led major modernization work across the platform, including migration from Rails 4 / MS SQL Server to Rails 7 / PostgreSQL on AWS.
• Designed and built production APIs consumed by customers, government institutions/agencies, mobile applications and internal operational tools.
• Worked across Rails, Python/FastAPI, Elixir/Phoenix, .NET Core, Redis, PostgreSQL, MS SQL Server, AWS, Linux, Docker, Terraform and CI/CD.
• Built and maintained Python/FastAPI services for API gateway and backend integration workloads.
• Used Python, Polars, Pandas, PostgreSQL and MS SQL Server to process, reconcile and validate operational and financial datasets.
• Diagnosed and resolved data correctness, rounding, performance, reliability and integration issues across production workflows.
• Used AI/LLM tooling for codebase analysis, implementation planning, refactoring support, test generation, debugging and structured development workflows.

Relevant technologies Ruby on Rails, Python, FastAPI, Elixir/Phoenix, C#/.NET Core, PostgreSQL, MS SQL Server, Redis, AWS, EC2, RDS, Docker, Linux, Terraform, CI/CD, Polars, Pandas, OpenAPI

• Avero — silent retail loss prevention. Solo-built a sensor-to-gate retail loss-prevention system across 40+ stores, tracking 1M+ customer movements per month — full pipeline from 3D ceiling sensors through edge processing (~100 events/sec) to silent gate decisions, signal-to-decision in milliseconds.
• Migrated edge software from Go to Rust after AI-assisted analysis surfaced lock contention and runtime delays; identified and patched a memory leak in the production MQTT library along the way.
• Built signal-recording and replay harnesses so AI-driven refactors and algorithm changes are validated against captured real-world traffic, with daily AI QA passes that score live behaviour (track stitching, group handling, tailgating detection) against expectation each release.
• Built AI-managed release flow and incident triage — humans only get paged when AI judges a real call is needed, keeping the system silent until it actually shouldn't be.
• Skvass — remote gym access automation. Solo-built a Raspberry Pi access bridge for a squash gym connecting a third-party booking platform with biometric scanners and physical gate hardware — designed, built and operated remotely from another country, never on-site.
• Owned the architecture: canonical mapping between booking-platform identifiers and biometric enrolment IDs, changed-only sync to preserve device biometric state, force-all recovery, and QR / NFC / digital-wallet credential paths.
• Used AI to read the booking-platform API and the scanner WebSocket protocol from sparse documentation and observed device messages, and as a remote hardware-debugging partner — a "scanner not opening the gate" investigation was traced through logs and command traces to a wiring issue diagnosed from a country away.
• ComeUnity — Danish university community platform. Built and evolved a Laravel 12 / Statamic 6 backend / CMS powering a Danish university community mobile app and company portal.
• Built substantial parts of an Expo / React Native mobile app, including API integration, authentication / profile flows, messaging / social features, content delivery and deep linking.
• Designed and built a semi-automated AI-assisted OpenAPI client workflow that keeps the mobile app's API layer aligned with the published contract — generated client, hand-written wrappers, TypeScript types, mocks and tests all move together each time the backend changes, with AI inspecting each contract diff for anomalies and Figma context linked through Claude Code so design-driven backend changes land with their UI implications already visible.
• Quake Monitor — earthquake exhibition at Harpa Concert Hall. Built the live earthquake visualisation now running on an 85-inch 4K screen inside the volcano exhibition at Harpa — custom Iceland map, real-time projection, exhibition admin and AI-built calibration tooling. Shipped end-to-end without ever visiting the venue, with installer photos and AI-assisted QA standing in for site visits.
• Built AI-assisted tools and custom-code workflows for sigrun.com — plugin / custom-code support and website maintenance / debugging automation.
• Worked on a Swiss public transportation platform integrating backend software with real-time passenger information systems, signs / screens, routes, delays, alerts and operational messaging.
• Acted as CTO / senior contractor for GetLocal, leading development of a SaaS e-commerce and site builder platform.
• Worked as Tech Lead / consultant for the City of Reykjavík, helping shape in-house software development and delivery of municipal digital services, including a citywide one-click school enrollment solution.

Relevant technologies Python, FastAPI, Rust, Go, Ruby on Rails, Laravel, Statamic, React Native, Expo, TypeScript, OpenAPI, PostgreSQL, TimescaleDB, SQLite, Redis, Prometheus, Grafana, MQTT, WebSockets, Docker, Linux, nginx, AWS, Azure, CI/CD, Raspberry Pi, TCP/IP, RS485, Wiegand

• Wrote and maintained code serving ads across a very large production network.
• Worked on vendor integrations, analytics/reporting tooling, backend systems and operationally significant production workflows.
• Contributed to systems where performance, reliability and scale were central concerns.
• Worked in a distributed, asynchronous, remote-first engineering environment.

Relevant technologies PHP, JavaScript, backend systems, analytics/reporting, vendor integrations, high-scale production systems, remote/asynchronous collaboration

• Built media streaming and digital delivery platforms.
• Designed backend systems for catalog management, purchases, streaming and telecom integration.
• Worked with major music labels, artists and commercial partners.
• Built infrastructure-heavy systems involving encoding, media delivery, ticketing and digital commerce.