Right tool for the job
Pragmatic, never dogmatic.
We choose technology to fit the problem — .NET, Go, or whatever the job calls for — not the other way round. No rewrites for fashion, no resume-driven architecture.
Nullsoft ehf. Software Consulting & Architecture
Reykjavík · 64°08′ N Reliable software systems, engineered to endure.
Senior software architecture and engineering for teams building payments, fintech and other systems where reliability is not optional. We work hands-on — from architecture to production — in .NET, Go, and the right tool for the job.
01/ 06
Services
Senior help on the parts that are hard to get right.
Five ways to work together — from a sharp architecture review to embedding for a full build. Senior from the first conversation to production.
Software Consulting
Pragmatic senior guidance on hard problems — architecture reviews, technical due diligence, and getting stuck systems moving again.
Software Architecture
Domain-driven design, clear boundaries, and pragmatic patterns — including event sourcing where it genuinely fits. Systems that stay maintainable as they grow.
Cloud & Infrastructure
Pragmatic cloud, zero-downtime deploys, observability you can operate on, disaster recovery, and real operability.
Team Augmentation
Embedding with an existing engineering team as a senior contributor — raising the bar, not just adding hands.
Reliable Systems
Production engineering: defense-in-depth validation, fail-closed defaults, audit trails, and health-gated releases.
02/ 06
Approach
A method, not a toolkit.
Four principles behind everything we ship — the things that make software survive contact with production, whatever it is built in.
Reliability first
Built to endure.
Defense-in-depth validation, fail-closed defaults, zero-downtime releases, and observability you can actually operate on. Systems that hold up when it counts.
Model the domain
Understand it before you build it.
We design around the real shape of the business — clear boundaries, honest names, the right invariants — so the system stays maintainable as it grows.
Senior, end to end
No drift from intent to production.
The people who advise are the people who build and operate. No hand-off layer, no telephone game between the design and the system that ships.
03/ 06
Selected Work
Three products, built and operated end to end.
Not client logos — our own systems. Designed, built and run by us, in production today, with the real scope and the real trade-offs.
CASE 03·A — PASSES & TICKETING
Visit yoyopass.com yoyopass.com
A digital pass, ticketing and wallet platform — issue, distribute, and validate passes at scale.
Highlights
- Full pass lifecycle, audited. Issue, activate, use, void, extend, suspend — every state change kept as an immutable record, for a complete, compliance-ready audit trail.
- Sub-100ms QR validation. The real-time scanner checks six conditions per scan, with anomaly detection and fraud-correction by entry retraction.
- Apple & Google Wallet. Pass generation with device registration and push updates across both wallets.
- Hardened REST API. HMAC-signed, with idempotency keys and an 82-test security suite covering replay, XSS, and rate-limiting.
- Zero-downtime releases. Blue-green deploys that hold traffic until the new version is fully ready — no downtime, no half-migrated state.
CASE 03·B — MULTI-TENANT COMMERCE
Visit kauply.is kauply.is
A multi-tenant SaaS e-commerce platform — independent online stores, each fully isolated.
Highlights
- Full tenant isolation. Every store runs on its own database — no shared-database bottleneck — with continuous streaming backups and tested disaster recovery.
- 15+ composable modules. Catalog, checkout, payments, inventory, shipping, subscriptions, loyalty, reviews, gift cards — loaded per store.
- Multi-provider payments. Six payment providers — Stripe, Rapyd and more — behind a single abstraction.
- Operable by design. Invite-based onboarding; one-command blue-green deploys with health checks and disaster-recovery-tested tenant migrations.
CASE 03·C — TIME TRACKING & BILLING
Visit timabok.is timabok.is
Tímabók — time tracking and billing for teams that bill by the hour, from clock-in to the approved report delivered to accounting.
Highlights
- Every hour, an immutable record. Clock-ins, corrections and rate changes are events, never overwrites — the full history stays queryable, and approved billing periods reject edits.
- A tenant is a vault. Every company gets its own event store and its own encryption key — isolation by construction, not by convention.
- GDPR erasure by crypto-shredding. Personal data is sealed per identity; erasure destroys the key. Nothing to scrub, nothing to miss.
- From rates to a delivered report. Layered, effective-dated hourly rates resolve as of the day the work was done; billing runs lock the period, collect approval, and deliver straight to accounting.
- Automation-ready. REST API, CLI and an MCP server — scripts and AI agents are first-class users, under the same auth and audit trail as the UI.
04/ 06
Experience
Senior engineering, where reliability is not optional.
Engagements across fintech, banking and aviation — honestly scoped, mostly in .NET. A deep, multi-year engagement at Rapyd, with selected work across banking and aviation over the years.
Rapyd
Global fintech & payments A multi-year engagement — senior software engineering and architecture on payments systems at global scale, primarily in .NET.
Íslandsbanki
Banking A contract engagement at one of Iceland's largest banks — engineering on systems where correctness and auditability come first.
Icelandair
Aviation · flag carrier Selected engagements with Iceland's flag-carrier airline.
Air Atlanta Icelandic
Aviation · ACMI, cargo & charter Selected engagements with a global ACMI, cargo and charter airline.
05/ 06
About
Senior, independent, hands-on.
Nullsoft is a senior, independent software practice — we design, build, ship and operate the systems our clients depend on.
Plenty of consultancies put a senior name on the proposal and juniors on the keyboard. We work the other way around: senior, hands-on architecture and engineering, from the first whiteboard to production.
That senior focus is the point. No hand-off layer between strategy and implementation, no telephone game, no drift between the design that was sold and the system that ships.
Based in Iceland, working remotely with international clients — fintech, banking, airlines and product companies that need senior architecture, a reliability reset, or an extra senior pair of hands. Mostly .NET and Go, and the right tool for the job.
- Practice
- Independent, senior
- Based
- Iceland
- Works
- Remote, international
- Entity
- Nullsoft ehf.
06/ 06
Contact
Start a conversation.
FIG. 06 — AVAILABILITY
Have a hard systems problem? Let's talk.