Sveinbjörn
Geirsson

Senior backend & platform engineer

TypeScript · PostgreSQL · Cloudflare Workers · Java / Scala · Rust

Reykjavík · on-site or remote

+354 849 2544

github.com/Raudbjornlinkedin.com/in/sveinbjornG
Download CV PDF · 2 pages sveinbjorn.dev · github.com/Raudbjorn · linkedin.com/in/sveinbjornG

Over a decade building financial systems (card settlement at Korta/Rapyd, pension-fund systems for 10 Icelandic funds, including Central Bank regulatory reporting) and now a SaaS platform on Cloudflare and PostgreSQL. I design for failures you can see and code the next engineer can change.

Experience

Aug 2025–present

Platform & search

Senior Developer · Massif Network

Location and media platform for film production. I co-own the platform with the CTO/founder as a two-person engineering team, across application, backend, and infrastructure.

  • Built durable processing from a PostgreSQL queue (PGMQ) through a broker Worker using Hyperdrive, service bindings, and Durable Object coordination. Bounded execution, retries, and dead-letter handling make failures visible.
  • Reworked test configuration and CI orchestration: a documented warm-cache comparison fell from 9m08s to 3m24s, with explicit test-environment separation.
  • Introduced Cloudflare Workers and R2 into the stack for media storage, authenticated image delivery, uploads, and embeddings.
  • Consolidated the separate web and admin applications into a pnpm/Turborepo monorepo that later absorbed the Workers services and their tooling.
  • Built organization-scoped hybrid and multimodal search with index repair. Ran a 670-case enrichment A/B that detected no relevance gain (p = 0.75) and dropped the feature rather than add pipeline complexity.
  • Built location similarity on Voyage AI embeddings: vector operations score how alike two film locations are, and drive search ranking.
Durable processing path A row created in PostgreSQL is dispatched through its work queue (PGMQ) to a broker Worker that leases and retries work with bounded reads, then calls domain Workers over service bindings for metadata, embeddings, search repair and geocoding. Work that exhausts its retries goes to a dead-letter queue. PostgreSQL row created PGMQ work queue broker Worker lease · retrybounded reads domain Workers metadata · embeddingssearch repair · geocoding service bindings retries exhausted dead letter
  1. PostgreSQLRow created
  2. PGMQWork queue
  3. Broker WorkerLease · retry · bounded reads

    Retries exhausted: work goes to the dead-letter queue.

  4. Domain WorkersVia service bindings for metadata, embeddings, search repair, and geocoding.
Durable processing path at Massif: work created in the database survives the trip to the edge, or lands somewhere visible when it doesn’t.

Stack: Cloudflare Workers / R2 / Wrangler · TypeScript · SvelteKit · PostgreSQL / Supabase · Meilisearch · Voyage AI

2022–2025

Pension systems

Software Engineer · Reiknistofa Lífeyrissjóða

Shared core systems for 10 Icelandic pension funds, roughly a third of the market.

  • Developed and maintained IBM Informix pension systems for payments, collections and contribution statements; mortgages, bonds and securities; and disability, retirement and child-pension applications and other accrued benefits.
  • Integrated RL’s core systems with the Central Bank of Iceland’s reporting system in 2023–2024, including the mortgage-obligation register reporting each fund’s loan balances and arrears.
  • Delivered the quarterly assets, liabilities, and market-exposure report to the Central Bank on time every quarter, running it manually when the regulator’s merger into the Central Bank retired the old domain and broke the XML schemas.
  • Set up and operated an X-Road security server answering pension-rights queries from Tryggingastofnun and Sjúkratryggingar Íslands.

Stack: IBM Informix · SQL · X-Road

2013–2022

Payments & settlement

Software Developer, later Senior Developer · Korta (acquired by Rapyd)

Joined Korta from university as one of its first developers; later helped newer developers navigate its payment systems. By 2022 Korta processed ~ISK 230bn (≈ $1.7bn) a year, settled in ISK, EUR, USD, and GBP.

  • Developed settlement and payment-distribution logic for fees, rolling reserves, refunds, payment splitting and withholding, and settlement-frequency rules across domestic interbank (Central Bank large-value) and SEPA/SWIFT transfers, with logging and traceability throughout.
  • Mapped Visa/Mastercard reconciliation, interchange, and chargeback data to accounting codes across multiple currencies and cost/value dates, classifying transactions by region (domestic/EEA/international) and card product, including when an accounting day could be closed.
  • Processed FX rates from Visa, Mastercard, and central banks for multi-currency settlement.
  • Built volume and balance reporting for payment facilitators, and reporting for fraud and chargeback resolution.
  • Made core financial data available to frontend teams through IBM DB2 data services, without requiring them to know the underlying systems.

Stack: Java · Scala · IBM DB2 · OAuth 2.0

Technical skills

Cloudflare
Workers, R2, Wrangler, Hyperdrive, Durable Objects, KV, and Secrets Store; service bindings, local development, staging/production configuration, and deployment workflows.
Backend & data
Multi-tenant SaaS, TypeScript, PostgreSQL, Supabase, SQL and row-level security (RLS), OAuth 2.0, authentication and authorization.
Search & delivery
Hybrid search and vector search (Meilisearch), embeddings, retrieval-augmented generation (RAG), retrieval evaluation, Vitest, Playwright, pgTAP, CI/CD.
Infrastructure
Docker / Podman, k3s, Terraform, Ansible, GCP and AWS; observability with Datadog, Prometheus, Sentry, and Grafana / Loki; OpenID Connect; WireGuard / Tailscale.
Broader experience
SvelteKit and Svelte; Java, Scala, and IBM databases in financial systems; Go and Rust developer tools; Python and MCP tooling; C++ / SYCL inference work.
Languages
Icelandic (native), English (fluent).

Selected projects

Independent work on developer tools, image processing, and local inference.

Developer tooling

spoon

A GitHub fork-network analysis tool, written in Go, that discovers forks and ranks them by novelty. Public, 356 commits.

github.com/Raudbjorn/spoon

Local inference

SYCL & Intel Arc inference work

A local inference runtime integration with supervised model serving, runtime identity checks, and cancellation. Maintained a downstream llama.cpp fork for Intel Arc: SYCL flash-attention and XMX kernel tuning, with reproducible correctness and benchmark checks.

github.com/Raudbjorn/ggml-llama.cpp

Education & recognition

2010–2013

University of Iceland

BSc, Computer Science. Teaching assistant during the final two years.

2014–2023

Courses

Cryptography, Software Security, and Usable Security (Coursera, 2014–15); Functional Programming in Scala (2016); Rust (2018); Ansible (2023).

2016

Voting-system security disclosure

Identified and reported a CSRF vulnerability in wasa2il, the Icelandic Pirate Party’s online voting system, that could change a logged-in member’s vote. The maintainers acknowledged the report and fixed the affected election methods.

github.com/piratar/wasa2il/issues/132

2021

Rapyd internal hackathon winner

Part of the winning team, among 200+ participants from 6 countries, building a working WhatsApp wallet proof of concept using the Rapyd Wallet and WhatsApp Business APIs.

github.com/Rapyd-Samples/whatsapp-checkout

References

Tómas Árni Jónsson

Software Specialist · Deloitte

Worked together on RL’s Central Bank reporting integration, 2023–2024.

Þráinn Guðbjörnsson

Chief Risk Officer · Festa Pension Fund

Worked together on Korta’s early systems as two of its first developers, 2013–2017.

Contact information available on request.