[Guide] Ethereum Node Types Explained (And Why They Can Make or Break Your Debugging)

Ever had an eth_call work perfectly one day… then fail the next?
Or a debug_traceCall that times out for no clear reason?
Chances are — it wasn’t your code. It was your node.

Over the last few months, I’ve been writing deep dives on Ethereum development. From decoding raw transactions and exploring EIP-1559 & EIP-4844 to working with EIP-7702 and building real transactions in Go.
This post is a natural next step: understanding the nodes that actually run and simulate those transactions.

In this guide, you’ll learn:

• Full, Archive, and Light nodes — what they store, what they don’t, and why it matters for your work
• Why eth_call might fail for historical blocks
• Why debug_traceCall works on one RPC but fails on another
• How execution clients handle calls differently
• When running your own node makes sense (and what it will cost you)

Key takeaway:
Your node type and client decide what data you actually get back and that can make or break your debugging, tracing, and historical lookups.

If you’ve ever hit:

• missing trie node errors
• Traces that mysteriously fail
• Calls that work locally but not in prod

this post explains exactly why.

Read this post: https://medium.com/@andrey_obruchkov/ethereum-node-types-explained-and-why-they-can-make-or-break-your-debugging-fc8d89b724cc
Catch up on the previous ones: https://medium.com/@andrey_obruchkov
Follow on SubStack: https://substack.com/@andreyobruchkov

Question for the devs here: Do you run your own full/archive node, or stick with hosted RPC providers? Why?