C# Services for Product and SaaS Teams

Outsource C# and .NET for enterprise SaaS teams. ASP.NET Core APIs, Azure integrations, Framework migration, and dedicated nearshore squads.

We use the Framework Bridge Test in discovery to decide whether your next increment needs a fixed-scope project, a dedicated squad, or embedded specialists inside your rituals. Typical stacks include ASP.NET Core 8, .NET Framework 4.8, EF Core, SQL Server, Azure Service Bus, xUnit.

Reviewed by Javier Uanini, Founder and CEO, Siblings Software. Last reviewed 2026-06-16.

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What this service covers

We ship C# work where Framework debt, Azure identity, and audit trails cannot wait for a big-bang rewrite.

ASP.NET Core APIs and services

REST and gRPC endpoints with OpenAPI contracts, idempotency keys, and structured logging aligned to your observability stack.

Legacy Framework modernization

Strangler-fig extractions, multitargeted libraries, and IIS-to-Kestrel migration paths with parity tests.

Azure and enterprise identity

Azure AD, MSAL, Key Vault, Service Bus, and Functions wired with least-privilege IAM.

Data and performance tuning

EF Core query plans, SQL Server indexing, and batch jobs with measurable p95 targets before sign-off.

Who this is for

Enterprise SaaS on dual .NET stacks

Framework services still pay the bills while Core microservices must ship this year.

ISVs selling to regulated buyers

SOC 2, HIPAA, or carrier audits need code owners who document change control.

CTOs consolidating Microsoft stacks

Mobile, API, and admin portal should share contracts, identity, and release cadence.

Teams blocked on performance

p95 drifted on hot endpoints and internal hires have not cleared the backlog.

How delivery works

  1. Discovery (3 to 5 days). Scope, risks, access, and the Framework Bridge Test verdict on engagement shape.
  2. Team assembly (5 to 10 days). You interview engineers before sprint one. Replacements handled if fit is wrong.
  3. Sprint zero. CI, environments, observability, and definition of done aligned with your team.
  4. Two-week sprints. Demos, retros with named action owners, and shippable increments.
  5. Handoff. Runbooks, ADRs, and paired sessions. Optional retainer for audits or seasonal scale.

Team composition

Service pod (4 seats)

C# tech lead, two senior backend engineers, QA on API contracts.

Modernization squad (6 seats)

Adds data engineer for SQL tuning and part-time DevOps on Azure Pipelines.

Program engagement (8 to 10 seats)

Multiple extraction streams, shared platform bench, and release manager for carrier cutovers.

Pricing and engagement models

Fixed-scope C# modernization programs typically land USD 15K to 120K for ten to twenty week extractions. Dedicated .NET squads run USD 12K to 60K per month. Staff augmentation for senior C# engineers runs USD 4K to 9K per month per person.

Compare C# staff augmentation, dedicated C# team, C# sibling services, API development outsourcing.

Comparison with freelancers, in-house hiring, and staff augmentation

Offshore body shops quote low rates but miss Framework edge cases. In-house hiring for dual-stack .NET skills takes quarters. Nearshore squads with migration experience are usually the fastest path to carrier deadlines.

Example project: Veridian Claims Hub

Composite illustrative scenario based on common C# outsourcing patterns.

Veridian Claims Hub multitargeted validation libraries shared between Framework and .NET 8 services, cleared recurring SQL deadlocks on batch ingestion, and shipped carrier webhooks without IIS downtime.

  • Batch job p95: 9.4s to 1.2s
  • Recurring SQL deadlocks: 3 per month to zero
  • Carrier webhook success rate: 94.1% to 99.6%
  • Framework-to-Core shared library coverage: 0% to 78% of hot paths in eleven sprints

Explore published work in our case studies. Authoritative reference: C# documentation.

Risks and how we reduce them

Big-bang rewrite pressure

We extract by service with parity tests unless audit proves rewrite is cheaper.

EF Core N plus one surprises

Query plans are reviewed in sprint zero on every hot endpoint.

Azure cost drift

Functions and Service Bus tiers are sized against measured traffic, not defaults.

Signing and secret sprawl

Key Vault references and rotation policies documented before production cutover.

Frequently Asked Questions

When hot paths need independent scale, audit boundaries, or team ownership and parity tests can run in shadow first.

Yes, with documented IAM, break-glass, and no long-lived secrets outside Key Vault.

That is the default pattern. Parallel releases with shared contract tests beat freeze-the-world migrations.

Service-slice pricing after a one-week dependency and query-plan audit.

Fixed-scope milestones with rollback flags or a dedicated squad if carrier specs change weekly.

Staff augmentation in five to ten business days. Squads in one to two weeks after access.

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