Enterprise Integration Interview Prep for Senior .NET Developers
Got a job description mentioning SAP, Salesforce, commercetools, ERP, CRM or event-driven integration — but you've spent your career building .NET services?
Learn enough enterprise integration architecture to survive the interview without pretending you've been an SAP consultant for 10 years.
6 lessons · 230 interview questions · one offline HTML study app
One-time purchase · One HTML file · No install, no account
You Will Know How to Answer
Who owns customer, order and product data?
Why shouldn't checkout wait for SAP?
What if SAP creates the order and then times out?
How do retries avoid duplicate orders?
Sync or async — and how do you defend the choice?
Outbox and inbox, idempotency, DLQ, reconciliation?
Where do Salesforce, commercetools and SAP each belong in the architecture?
What's Inside
6
Lessons
+ bonus appendix
230
Drill questions
across 28 sections
104
Flashcards
terms & definitions
152
Diagrams
flows & sequences
41
Code samples
C#, SQL, JSON, HTTP
45
Quiz questions
each with reasoning
76
Modules
mark as you read
3h45
Reading time
at your own pace
Who This Is For
This is for you if
- You're a backend engineer interviewing for enterprise integration roles — you know distributed systems, but not SAP.
- You're a .NET developer joining a team that already runs commerce, ERP and CRM side by side.
- You have to say something credible about idempotency, ownership and reconciliation next week.
Not for you if
- You want SAP implementation training, ABAP, or certification prep.
- You need hands-on access to a real S/4HANA system.
This teaches the integration architecture and the vocabulary around it — not how to configure the ERP.
The Six Lessons
1
ERP, CRM, commerce and the full order lifecycle
25 min
One company buys 20 monitors. Follow that purchase until it becomes an invoice, a payment and an accounting entry — and watch how many separate business objects it creates along the way.
2
commercetools from a developer's perspective
30 min
Product types, variants, prices, carts, update actions, optimistic concurrency, messages and subscriptions — and what the .NET side actually looks like.
3
Salesforce from a developer's perspective
30 min
Account, Contact, Lead, Opportunity, SOQL, external IDs and upserts, CDC versus platform events — and why a PATCH is not a database write.
4
SAP S/4HANA from a developer's perspective
35 min
Business partner, material, plant, sales area, sales order, delivery, goods issue, billing. OData, released APIs, communication arrangements and business events.
Appendix: the robust consumer Bonus
20 min
Inbox, sequence checkpoints, gap detection and reconcile-from-source — worked through one .NET consumer that keeps SAP order status in step with commercetools.
5
Dapr and event-driven integration
40 min
At-least-once delivery, the inbox that does not save you, the dual write, the transactional outbox, dead letters with an owner — and what Dapr does not do for you.
6
Design the complete system in an interview
45 min
The vague brief, answered in the order that scores: ownership, flows, contracts, failure, operations. Ends with the two-minute answer.
Five Ways to Study
Lessons
Read with a document-flow rail across the top that lights up to show which stage of the order lifecycle you're in. Mark modules as read; each lesson gets stamped when you finish it.
Flashcards
104 terms, filterable per lesson, shuffle, keyboard-driven.
Quiz
45 questions, one attempt each — then the reasoning appears.
Interview drill
230 questions, from "what is an SKU" to "prevent duplicate SAP orders". Answer out loud, grade yourself, then filter to Weak only and repeat until it's empty.
Who owns it?
Ten rounds of source-of-truth calls — the question this stack gets asked about most.
Plus a one-page cheat sheet to read on the way to the interview.
FAQ
What does an enterprise integration interview actually ask?
Not how to call a sales order API. Who owns the customer record, what happens when SAP times out after creating the order, why checkout doesn't wait for the ERP, and how you stop duplicate orders when a message arrives twice.
Do I need SAP experience?
No — it's written for engineers who know distributed systems but have never touched an ERP. It won't make you an SAP consultant. It will let you hold an architecture conversation with one.
Is this a course platform or a subscription?
Neither. It's a file. There is nothing to log into and nothing to cancel.
Can I put it on my phone?
Yes — it's responsive down to phone width. Progress is per-browser, and Export moves it between devices.
Will I get updates?
I used it to prepare for these interviews myself, so occasional updates may follow from that experience — but treat it as a snapshot, not a maintained subscription.
Does it cover the interview I have on Friday?
If that interview involves commerce, an ERP and a CRM talking to each other over messaging, the answers are in here. If it's an SAP configuration role, it isn't.
Requirements & Honest Limits
- Any current browser. Chrome, Edge and Firefox keep your progress between sessions when you open the file directly. Safari refuses storage to local files, so there's an Export button that saves progress as a JSON file you can import back.
- Progress and self-grading are stored in your browser, not on a server. Nobody sees your scores.
- The platform details reflect published vendor documentation at the time of writing. APIs move — verify anything version-specific against the current docs before you quote it in an interview.
- English only. No video, no audio — it's a reading and drilling course.
- It will not make you an SAP consultant. It will let you hold an architecture conversation with one.
Who Wrote This
Pavel Osadchuk
Principal .NET / C# Engineer · Software Architect
14+ years building .NET services and distributed systems. I wrote this course to prepare for exactly these interviews myself — the gap between "I can build any of this" and "I've never touched an ERP" is the one it closes.
More about my backgroundWalk into that interview with the answers
Six lessons, 230 drill questions, one HTML file. One-time $79.99 — no account, no subscription.
Get the course on Gumroad$79.99 once, weighed against the salary of the role you're interviewing for. The file is yours — no account, no subscription, nothing to renew.
I post what I'm building — new widgets, Windows dev notes, and the occasional thing that didn't work.
Follow on X