[Andrei](https://github.com/sandreim) leads the parachain engineering team. His team works on all the small/big optimizations to make Polkadot scale and support more parachains. We as the fellows think that all the contributions he has done approve rank 2. We see him on a good path to get a fellow in the future as well :)

Here is a list of him on all the things he has done while working on Polkadot:

> My contributions focus mostly on the node side and I could split them into 4 categories:
>- Scalability/performance 
>- Observability, monitoring and debugability 
>- Zombienet and integration testing
>- Node resilience
>
>On Scalability/performance:
>- 2023 Q2 plan and implementation of tasks to enable scale up to 300 paravalidators and 70 parachains - https://github.com/paritytech/roadmap/issues/25 
>- 2023 Q3/Q4 plan and work items for 500 paravalidators and 100 parachains https://github.com/paritytech/roadmap/issues/26  
>- Monster PR - V2 assignments support, Versi tested, currently pending reviews   - https://github.com/paritytech/polkadot/pull/7038 
>- Fixes for gossip issues at scale - https://github.com/paritytech/polkadot/pull/6401 
>
>On observability, monitoring and debugability
>- https://github.com/paritytech/polkadot-introspector - Started this project with an empty repo and established a roadmap for the project. My main code contribution is the initial design and implementation:
>    - Initial design, architecture and partial implementation 
>    - Parachain Tracer Tool -  https://github.com/paritytech/polkadot-introspector/tree/master/parachain-tracer 
>    - Block time Monitor Tool - https://github.com/paritytech/polkadot-introspector/tree/master/block-time 
>    - Storage core components: https://github.com/paritytech/polkadot-introspector/pull/69 
>- Per subsystem CPU usage tracking: https://github.com/paritytech/substrate/pull/10196 + https://github.com/paritytech/substrate/pull/10196 
>- Runtime metrics https://github.com/paritytech/polkadot/pull/4483 (later used to debug inherent weight issues during the Polkadot dispute storm incident: https://forum.polkadot.network/t/polkadot-dispute-storm-the-postmortem/2550)
>- Authority status of nodes, currently used by community to figure out if their node is in the active set: https://github.com/paritytech/polkadot/pull/4699 
>- Fixing Multiple other PRs that add metrics, improve logs etc that I won’t mention here
>
>On integration testing:
>- Contributed to Zombienet design, features and roadmap with suggestions from the perspective of the Parachain Core Team
>- New test collator with configurable CPU and PoV size (predates the Glutton work) used in CI - https://github.com/paritytech/polkadot/pull/4797
>- Malus support for triggering disputes against valid and for invalid, this is the way the Parachain team  tests disputes on Versi and in CI  - https://github.com/paritytech/polkadot/pull/5011 
>- Created the initial suite of Zombienet integration CI tests for disputes:
    -  https://github.com/paritytech/polkadot/pull/5857 
    - https://github.com/paritytech/polkadot/pull/4859 
>
>Node side resilience 
>- Finality stalls become way more manageble: https://github.com/paritytech/polkadot/pull/6106 + https://github.com/paritytech/polkadot/pull/6054 
>- https://github.com/paritytech/polkadot/pull/4735
>
>Investigated, fixed and wrote a post about a Polkadot network issue that affected the ecosystem.
>- https://forum.polkadot.network/t/polkadot-dispute-storm-the-postmortem/2550
>- https://github.com/paritytech/polkadot/pull/6937 


- **Problem Statement:** Recognizing Andrei's significant contributions to Polkadot's scalability and performance optimizations, observability, monitoring, and debugability, integration testing, and node resilience.
- **Significance:** Acknowledging Andrei's pivotal role in enhancing Polkadot's functionality and performance through various technical contributions.
- **Proposed Solution:** Continuation of Andrei's impactful work in improving Polkadot's scalability, performance, observability, and resilience.
- **Expected Outcomes:** Continued advancements in Polkadot's technical capabilities and potential recognition for Andrei as a fellow in the future.

#9 [Fellows] Add & Promote Andrei Sandu to rank 2