No company is perfect. Every peak brings with it a valley. And Apple had plenty of both this year.

Apple shipped a stunning amount of products in 2015 and made an incredible amount of money doing it. Yet that kind of scale can create strain and that level of success can hide problems. Some will be aberrations that happen once and then seldom if ever again. Others, though, will hint at patterns, and at potentially larger issues both now and into the future. (And no, I'm not just talking about the appalling lack of hoodies at the redesigned Company Store...)

Part of iMore's mission over the last couple of years has been to explain, as best we can, why Apple does what it does. As we move into 2016, we'll be putting greater emphasis on critique, as well: Not just why Apple might do something, but how it could be improved. Not mindless internet rage hate, mind you—that's easy, and frankly, cheap. We'll be doing the hard work. It's something we've been doing in our in-depth reviews for a while, but we want to do a much better job separating and surfacing it for you in our editorials as well.

In that spirit, here are five areas in which I feel Apple struggled last year, and are symbolic of the larger struggles they'll face as a company going into 2016.

Apple Music not shipping as a beta

From the announcement at WWDC 2015, Apple Music was given an impossible job. It had to fit the needs of traditional customers with existing, potentially enormous local libraries. It had to provide streaming for a new generation of customers. It had to integrate new services like Beats 1 Radio and the Connect social network. And it had to do it all in one app.

The result was a dizzying, sometimes disjointed set of features and states, and the lack of anything approaching a clear and concise explanation on how it was all supposed to work or flow.

Taylor Swift had to "dear Apple" the company into paying artists during trial periods. Naked FUSE code strings were begging for localization at launch. Jim Dalrymple believed he'd lost almost his entire collection because the Settings screen didn't properly explain that switching off iCloud Music Library switched off both the new Apple Music and the old iTunes Match. Serenity Caldwell spent weeks helping people confused and concerned about everything from DRM to how to manage it all.

It was, to put it mildly, a mess.

Although it wouldn't have eliminated any of the technical issues, putting a beta label on Apple Music at launch would have better set customer expectations. Just like Siri did years ago. Just like iCloud Photo Library did earlier this year. Clearer explanations and better documentation at launch would have helped even more.

The Music app and Apple Music service themselves, divided against so many different and conflicting use cases, still require deep consideration, but the beta label would have given them some much-needed room to breathe. Instead of feeling frustrated today, customers could have felt like they were providing important feedback towards a better service tomorrow.

Supply constraints

The Apple Watch was announced in September of 2014 but only began to ship in April of 2015. Even then Apple ended up restricting orders to the online store and creating a try-on process for retail. And even then, trouble with a Taptic Engine supplier reportedly caused very low yields which, combined with production changes for some bands, resulted in some models not shipping until May or June.

Likewise, the iPad Pro was announced in September of 2015 but didn't ship until November and, even now, the Apple Pencil and Apple Smart Keyboard have been incredibly hard to find at retail and incredibly slow to ship online (At the time of this writing they're both still quoting 4+ weeks). Again, production changes and manufacturing yields are reportedly to blame.

Apple has experienced supply constraints with displays, sensors, and chipsets in the past but, with the notable exception of the white iPhone 4, they've been all but invisible to customers in the U.S. These weren't.

Holding the Apple Watch until summer of 2015 and the iPad Pro until spring of 2016 would have eliminated the constraints but at the expense of those who wanted one of the faster shipping Apple Watches or the iPad Pro without accessories. (And it likely would have hurt Apple with investors.)

By continually sprinting towards the shipping line, any significant problem can cause a miss. That everything comes together and Apple hits that finish line almost all the time is a testament to the company's operational skill. As Apple continue to scale, however, preventing or mitigating the misses will become increasingly difficult but also increasingly important.

Jeff Williams, Apple's long time senior vice president of operations, has just been officially promoted to chief operating officer. Hopefully that along with more communications and better setting of customer expectations will help.

Apple TV indecisiveness

Despite not having been refreshed since the spring of 2012, the new Apple TV launched in the fall of 2015 in a state that can only be called unfinished. What is there is really solid, so the designers and engineers obviously did their jobs and well, but just as obviously weren't given the focus and time needed to do it all.

No Siri for Music at launch, no way to share or link to apps, no persistent transiting of passwords to iOS devices, no concurrent update for the Remote app, incomplete TV Show app, and the list goes on. Some of that has already been fixed, both through constant server-side improvements and through a software update, but much still remains.

The reasons for both the long delay and the hot launch are the stuff of rumors—indecision over what kind of set top box to make, the allure of an over-the-top streaming video service—but that's the kind of noise Apple is traditionally really good at cutting through.

The box that eventually shipped is great, realizing so late that this was always the box that should have shipped was not so great. It almost feels like the Apple TV was treated as an accessory and a service, something closer to a Magic Trackpad or iTunes Extras than a device like an iPhone or iPad. It's not uncommon for accessories and services to languish. But devices—they ship.

The Apple TV, especially now that it has a developer platform attached to it, has to be treated as an iPhone or iPad-class device. It has to ship.

App Store sustainability

Last year, despite Apple's internal metrics supposedly reporting fewer "crashers" than ever before, the rise in "frustrators" led to the perception that iOS and OS X had lost its polish. Apple has seemingly recognized the issue—the company even rolled back the problematic discoverd—and begun making changes to improve not just the stability but the polish of their platforms. For the last few years, though, despite internal metrics showing greater volumes and revenues for the App Store than ever before, the loss of sustainability for independent apps has gone unaddressed.

Unless developers have casino-style gamifaction, venture capital and an exit strategy, an established subscription service, and/or see an app as a loss-leader for a broader business, making a living by making apps is only getting harder.

There are other issues to be sure: the aging iTunes infrastructure, the inability to purchase apps cross-platform and through the web, the lack of feature parity in the Mac App Store, crushing delays and endemic capriciousness in reviews, and the list goes on and on.

Apple may not see any of this as a problem or at least as a priority. The Google Play Store, with all its relative openness and options, hasn't produced a single universe-denting app that'd be impossible under the App Store as it currently exists. If it had, you better believe there would be incredible pressure to change.

Phil Schiller's recent appointment as head of App Store across all of Apple's platforms—thank you!—could be a sign that things will change. So might the iPad Pro and its need for truly pro-level software. And so might simply supporting the kind of software that's so great it reduces the chance of customers wanting to even experiment with other platforms.

Last year it remained a problem. This year it's an opportunity.

Product messaging

The Smart Battery Case for iPhone 6s is an incredibly well-engineered product that suffered from bad reviews and bad press because a) it has a wicked-obvious hump on the back, b) Apple didn't publicly explain the benefits afforded by the hump, and c) absent public explanation, many people—including those of us in the media—simply can't or won't put in the work needed to figure it out. A well-crafted webpage or Apple-style product video, silly as that sounds for an accessory, could have avoided the ton of cheap shots that followed.

That's a small example. WWDC 2015 is a bigger one. While some may enjoy the jocularity of recent Apple keynotes—and others not so much—few enjoyed the Apple Music segment. Even fans of Cue, Iovine, and Dre would be hard pressed to deny the timing, pacing, and polish of the keynote hit a brick wall right as they went into the one more thing.

The September event was much better, but the iPad story is still struggling to recapture the power of 2011's "We Believe" and the Apple Watch still hasn't coalesced around convenience.

That Steve Jobs was so central to Apple product messaging, both in personally communicating it and at line-item vetoing everything else, is part of what makes it such a challenge for Apple going forward. Yet Apple now has the advantage of greater openness and willingness to engage. Instead of the best voice in the world, they now have several world-class voices. Look no further than the incredible series of interviews and profiles this year.

Tim Cook or Phil Schiller just need to ensure they all stay laser-focused, and that needs of the products and customers always come first.

Your biggest fumbles?

Those are the biggest challenges I think Apple faced this year and the biggest things I think the company has to watch out for in 2016. What are yours?

Note: I spoke about several of these things with John Gruber on the 2015 year in review episode of his podcast, The Talk Show. So, for an expanded discussion, and John's take, be sure to check that out.