Let's deep dive into one of the first protocols we reviewed: 
@pooltogether currently one of only three protocols scoring a Stage 2 - the max grade!

No Loss Prize Savings Protocol.
Dive in: pooltogether.com/interfaces  🏆  /pool-together

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DeFiScan assesses and monitors the maturity and risks of DeFi protocols fostering Transparency and Security.
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UPGRADABILITY: can an update rekt me or significantly change the protocol?

Here again, @pooltogether scores a Low, considering the protocol is immutable with all permissions revoked.
Keep in mind however that PT harnesses other protocols, such as Aave, and inherits their risks

AUTONOMY: Could the protocol be impacted by the failure of tool or service it relies on?

@pooltogether uses Witnet Oracle for the randomness draw, and its failure would impact future draws (=rewards), but users can still withdraw their deposits and rewards accrued so far => Low

EXIT WINDOW: Can I get out of here before an update I disapprove of?

@pooltogether scores a Low risk score. Since the protocol is immutable, no change can be made; thus, no exit window is needed.

ACCESSIBILITY: Are there several ways to access the protocols, enabling users to keep interacting even if one fails?

@pooltogether gets a Low score, considering it has 2 UI independent from the team.

That's a wrap for @pooltogether, scoring an L on all five dimensions, leading to its classification as a Stage 2 DeFi protocol—the cream of the crop, one of the very few protocols that does not need training wheels to spin! 
Really cool and state of the art engineering of no-loss savings lotteries indeed @vitalik.eth

Full review can be consulted here: https://www.defiscan.info/protocols/pooltogether-v5

CHAIN: is the protocol built on solid grounds?

@pooltogether is deployed on mainnet, giving this instance a Low risk score. 
PT is also on Base, Arbitrum, and Optimism, which are @l2beat
stage 1 L2, and thus these instances would score a Medium risk score on that dimension