Boeing has faced intense scrutiny and pressure since a panel blew off a 737 Max 9 shortly after the plane, an Alaska Airlines flight, took off on Jan. 5. The episode raised fresh questions about the quality of the planes the company produces several years after two Max 8 planes crashed, killing nearly 350 people.

Interviews with more than two dozen current and former employees reveal longstanding concerns about quality, particularly as pressure increased to keep production going in the company’s factories.

Now, Boeing faces an immense challenge as it seeks to make changes that improve the quality of its products and regain its credibility with lawmakers, regulators, airlines and the public.

Here are some takeaways.

Quality issues date back years.

Current and former Boeing employees said that for years it felt as if quality took a back seat to keeping planes moving through its factories.

In interviews, former and current Boeing employees described worrying practices, including attempts to circumvent quality procedures. One was “inspector shopping,” in which workers would seek out inspectors willing to sign off on work with little pushback.

Boeing said it did not allow inspector shopping and had increased the number of quality inspectors for commercial planes 20 percent since 2019. Inspections per plane also rose a similar amount over that period, the company said.