For US software consultancies
Senior .NET capacity, company-to-company.
I'm Stipe Bošnjak. I run Devbox Limited, an Irish software company. I subcontract to US consultancies that have won regulated or data-heavy work and need a senior .NET engineer who can run with it. Twelve years of commercial C# and .NET, currently working in .NET 10.
What I get brought in for
Three kinds of engagement.
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Legacy .NET modernisation
.NET Framework to .NET 8 or 10, and the surrounding modernisation. Done at bank scale and at national-government scale, on systems that could not go down.
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Regulated backend work
Regulatory reporting, reconciliation, compliance integrations, mTLS and secure delivery, vulnerability remediation. The work where being wrong is expensive.
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A senior in front of the client
Someone who can sit with your client's compliance or risk people and defend the design, without you in the room to translate.
Proof
Two engagements. Both regulated, both at scale.
Clients are not named on a public page. Named on request, under NDA.
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Tier-1 investment bank · Global markets middle office
.NET Framework 4.6 to .NET 10, on a compliance path, without losing a record
A console application delivered audit records of significant user actions to a regulatory compliance API. An internal logging library pinned it to .NET Framework 4.6 and ran on a background thread the application could not control, so the code slept at intervals to stop logs being dropped.
I replaced it with direct delivery to the compliance API over mutual TLS, in small reversible steps. Deterministic event IDs let the API discard duplicates from a re-sent batch; records are marked processed only after a 200, so a failed batch retries on the next run. Current work on the same platform is remediating critical vulnerability findings and migrating libraries.
- 4.6 → .NET 10runtime migration
- Zeroaudit records lost
- mTLScompliance delivery
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National government department · Records processing
Six and a half years migrating a national records system in service
I led the legacy migration and modernisation of a records processing system used nationally: moving work off the legacy platform, reconciling data across government agencies, and building greenfield microservices for new capability alongside the system still running.
Continuous rather than big-bang. This is the experience behind every migration estimate I give you — including the ones where I say the safe answer is to leave something alone.
- 6.5 yearson the programme
- Cross-agencydata reconciliation
- Greenfieldservices beside legacy
How it works
The answers your ops person will ask for.
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Overlap
9am–1pm US Eastern, daily. Extendable to 4pm ET when a project needs it. That is the commitment, and it is the one I keep. I won't promise full US hours.
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Availability
Immediately after November 2026. Part-time overlap is possible sooner if you need to start before then.
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Contract
Company to company. Devbox Limited invoices your firm. No employment relationship, no payroll, no misclassification exposure, under the Ireland–US treaty.
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Paperwork
You collect a Form W-8BEN-E. Services are performed outside the US, so they are generally foreign-source: typically no US withholding and no 1099. Worth a two-minute check with your own accountant — this is not tax advice.
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Cover and terms
Professional indemnity cover at €1m. I'll sign your MSA and your NDA.
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What I'm not
One senior engineer, not a bench. You know exactly who shows up. No deep Docker or Kubernetes, no Python, no line management — if that's the centre of the engagement, I'm not your fit and I'll say so on the call.
Stack
- C# / .NET 10
- ASP.NET Core
- Azure
- SQL Server
- Entity Framework
- NHibernate
- WCF
- WPF
- MQ
- Elasticsearch
- Power BI
Next step
Tell me what you've won.
The domain, the stack, and roughly when you need someone. I'll come back within one business day with whether I'm the right fit — and say so plainly if I'm not.
Or email info@devbox.ie directly — ask for the CV and rate card.