In recent years, Boeing has faced several setbacks with the program. Problems with thrust links required rework on all four previous test aircraft and contributed to further delays. The company has also experienced financial difficulties and increased scrutiny from regulators such as the Federal Aviation Administration (FAA).

Jon Ostrower at The Air Current reported that "the FAA has approved Boeingto progress to the fourth phase of certification with the 777X. This phase, Type Inspection Authorization (TIA), will focus on systems demonstration." He added that "Boeing first began certifying the 777X in July 2024, and TIA is stage 2C in the certification process."

There are five main stages in aircraft certification; stage two is divided into four sections. The remaining steps include additional testing and ETOPS (Extended-range Twin-engine Operational Performance Standards) approval. Certification is expected by late 2025 or early 2026, aligning with Boeing’s current target for entry into service.

The development timeline for the Boeing 777X makes it one of the longest for any airliner derivative program. While based on an existing design rather than being entirely new ("clean-sheet"), significant changes have been made—including new wings, a longer fuselage, updated cockpit features, and cabin improvements.

Passengers can expect larger windows with dimming capability similar to those found on the Boeing 787 Dreamliner. Overhead bins have been redesigned for more luggage space, and cabin pressure altitude will be reduced to improve comfort.

Despite concerns about market demand due to its size, most customers ordering the Boeing 777-9 also operate Airbus A350s and plan to use their new jets as flagship aircraft. Several airlines intend to introduce upgraded premium cabins aboard their future fleets.

Qatar Airways and Emirates have confirmed they will launch new business class seats on their upcoming Boeing 777-9s. Singapore Airlines has previewed both first class and business class products planned for these jets as well as its A350s. Lufthansa has already rolled out some cabin products originally intended for debut on its own delayed deliveries of this model.