cumulocity-iot/c8y-architect-microservice-chassis-advisor

Cumulocity Microservice Chassis Advisor

When to Use

Invoke this skill whenever someone asks:

• "Which chassis / framework should I use for my Cumulocity microservice?"
• "Should I use NestJS, Spring Boot, .NET, or Python for my microservice?"
• "What is the best stack for a Cumulocity microservice?"
• "Help me choose between the available Cumulocity SDKs."
• Questions about trade-offs between NestJS, Nitro, Spring Boot, .NET Generic Host, or Python + FastAPI in the Cumulocity context.

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Procedure

Step 1 — Gather Requirements

Ask (or infer from context) the following. You do not need all answers; work with what is available.

| # | Question | Why it matters | |---|---|---| | 1 | What is the primary use case? (e.g. ERP bridge, SCADA agent, data pipeline, platform extension, analytics) | Narrows the shortlist immediately | | 2 | What is the team's primary tech stack? (TypeScript / Java / C# / Python / mixed) | Skill-fit is the strongest single factor | | 3 | Is official Cumulocity SDK support a hard requirement? | Only Spring Boot + Java SDK is officially supported | | 4 | What are the expected load characteristics? (low/bursty, medium/steady, high-throughput, mega-fleet) | Impacts runtime, footprint, and concurrency model | | 5 | Are there resource / cost constraints on the deployment? (e.g. tight memory limits, edge deployment) | Favours Nitro or .NET AOT | | 6 | Is AI / ML / data processing part of the microservice logic? | Strongly favours Python | | 7 | Is this a rapid PoC or a long-lived production service? | PoC → Nitro or Python; production → NestJS, Spring Boot, or .NET | | 8 | Are there enterprise governance requirements (e.g. auditability, support SLAs, supply-chain policies)? | Favours officially backed frameworks |

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Step 2 — Evaluate Against the Decision Matrix

Score the shortlisted options against the criteria below.

Rating: 🟢 High / Excellent   |   🟡 Medium / Good   |   🔴 Low / Limited

| Criterion | NestJS + @c8y/client | Nitro + c8y-nitro | Spring Boot + Java SDK | .NET Generic Host + C# SDK | Python + FastAPI | |---|:---:|:---:|:---:|:---:|:---:| | Team Skill Fit | 🟢 Web / TS teams | 🟢 Web / TS teams | 🟡 Java specialists needed | 🟡 .NET specialists needed | 🟢 Broad — data, DevOps, web | | Official Cumulocity Support | 🟡 Community | 🟡 Community | 🟢 Official & fully supported | 🟡 Community | 🟡 Community | | Cross-Cutting Features OOB | 🟢 Comprehensive | 🟢 Comprehensive | 🟢 Comprehensive | 🟢 Comprehensive | 🟡 Moderate | | Resilience Patterns OOB | 🟡 Via libraries | 🟡 Probes + libraries | 🟢 Resilience4j native | 🟢 Polly native | 🟡 Via tenacity | | Observability | 🟡 Via plugins | 🟢 Structured logging + OpenTelemetry | 🟢 Actuator + Micrometer | 🟢 OpenTelemetry native | 🟡 Via libraries | | Runtime Throughput & CPU Efficiency | 🟡 Medium | 🟢 High | 🟡 Medium | 🟢 High | 🟡 Medium | | Memory & Docker Image Footprint | 🟡 Medium | 🟢 Very Low | 🔴 High (🟢 Low with Spring Boot AOT) | 🟢 Low (🟢🟢 with AOT) | 🟡 Medium | | Cold Start / Startup Time | 🟡 Fast | 🟢 Very Fast | 🔴 Slow (🟢 Very Fast with GraalVM) | 🟡 Fast (🟢 Very Fast with AOT) | 🟢 Fast | | Scalability & Concurrency Model | 🟢 Async event-loop | 🟢 Async event-loop | 🟡 Thread-pool (reactive opt.) | 🟡 Thread-pool (async/await opt.) | 🟡 Async via asyncio | | Type Safety | 🟢 Strong (TypeScript) | 🟢 Strong (TypeScript) | 🟢 Strong (Java) | 🟢 Strong (C#) | 🟡 Partial (type hints, Pydantic) | | Boilerplate Required | 🔴 Heavy | 🟢🟢 None | 🔴 Very Heavy | 🔴 Heavy | 🟢 Minimal | | AI / ML & Data Integration | 🟡 Via npm libraries | 🟡 Via npm libraries | 🟡 Via libraries (DL4J, Spring AI) | 🟡 Via NuGet (ML.NET) | 🟢 Native — NumPy, Pandas, PyTorch | | Ecosystem Maturity & Community Size | 🟢 Large | 🟡 Nitro strong; c8y-nitro niche | 🟢 Very Large | 🟢 Large | 🟢 Very Large | | Long-term Commercial Backing | 🟢 NestJS Inc. | 🟢 Vercel-backed Nuxt/Nitro ecosystem | 🟢 Broadcom (Spring) | 🟢 Microsoft | 🟢 PSF + broad industry |

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Step 3 — Apply the Quick-Pick Rules

Use these rules to short-circuit the matrix for common scenarios:

| If… | Recommend | |---|---| | Team is Java-based and official support is required | Spring Boot + Java SDK — only officially supported chassis | | Team is TypeScript/Node and service will be long-lived, structured, and multi-protocol | NestJS + @c8y/client — strongest TS framework conventions and broad ecosystem for larger services | | Service is resource-constrained, startup-sensitive, or needs fast iteration with strong C8Y batteries included | Nitro + c8y-nitro — very small footprint, very fast startup, and strong built-in Cumulocity ergonomics | | Team is .NET/C# and throughput / image size matters | .NET Generic Host + C# SDK — especially strong with AOT compilation | | Service involves AI/ML, data enrichment, or analytics | Python + FastAPI — unmatched data science ecosystem | | Mixed team with no dominant skill and time-to-market pressure | NestJS (broad TypeScript adoption) or Python + FastAPI (low ramp-up) | | Enterprise governance requires a supported SLA | Spring Boot + Java SDK — only option with official Cumulocity backing | | Service involves complex business logic and heavy compute power for data analytics, image processing etc. | Spring Boot + Java SDK or .NET Generic Host + C# SDK — better suited for CPU-intensive workloads with enterprise-grade multi-threading | | Service is I/O-heavy but not CPU-bound (e.g. API gateway, protocol translator) | Nitro + c8y-nitro — efficient async I/O with strong Cumulocity integration | | Service handles and processes JSON-heavy data transformations | Nitro + c8y-nitro — efficient async I/O with strong Cumulocity integration | | Service needs many enterprise integrations (databases, message queues, external APIs) | Spring Boot + Java SDK or .NET Generic Host + C# SDK — mature ecosystems with extensive integration libraries | | Service needs fast development and deployment for a PoC or MVP | Nitro + c8y-nitro or Python + FastAPI — minimal boilerplate and fast iteration cycles |

Step 4 — Formulate a Recommendation

Structure your response as follows:

1. Primary recommendation — state the chassis and the top 2–3 reasons it fits the stated requirements.
2. Runner-up (if close) — one sentence on when to reconsider.
3. Trade-offs to watch — flag any 🔴 ratings on criteria that are important for this project.
4. Next steps — link to the relevant starter or documentation.

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Bundled Assets

| Asset | When to load | |-------|-------------| | references/dx.md | Use this if you want a detailed comparison of developer experience across different ecosystems |

Resource Links

| Chassis | Starter / Docs | |---|---| | NestJS + @c8y/client | NestJS · @c8y/client (npm) · Cumulocity Web SDK Docs | | Nitro + c8y-nitro | Nitro · c8y-nitro (GitHub) · Starter Template | | Spring Boot + Java SDK | Spring Boot · Java Microservice SDK (Docs) · Java Clients project · Maven Archetype for Microservice · Examples & Templates | | .NET Generic Host + C# SDK | .NET · Cumulocity .NET SDK · Cumulocity .NET Client | | Python + FastAPI | FastAPI · Python API (GitHub) · Python MS SDK (GitHub) |