Migrating to Unified Logging, Swift Edition

I have a new blog post up on our company blog. If you have a Swift project that is not yet using Unified Logging (os_log and friends), I think you’ll find this helpful. There are some surprising differences, for better and for worse, compared to NSLog and print statements.

If you’re brave, I also have an open-source Swift wrapper around the Unified Logging APIs which takes some of the edge off of the migration away from legacy logging techniques.

|  18 Sep 2018




Twitter Made Flesh

OH:

I unfollowed my wife. She came home one day, keys jangling against the dusk. Check this out, I said, making a witty joke about a reference, a joke I had made earlier that was laughed at by the right people. She dumped her bags on the chair by the door. I repeated the joke. She went on through the house, past me, past the joke she didn’t get, racing for her cozy clothes by the bed. It was a funny joke. It had a reference in it. She walked past the joke, past me. The right people had laughed at it. She put on her cozy clothes. I unfollowed her. She asked me later to explain the joke, but I had unfollowed her, so there was nothing else I could do.

I unfollowed my dad. He said something about “the Lord”. I don’t like what he believes. He doesn’t know about what I believe. It was family dinner out, at the restaurant where they had a shooting a week later when two men with guns shot and killed a third man who shot at the guests with a gun, and my Dad said something about “the Lord”, and that was one too many things about “the Lord” for me to hear that day. So I unfollowed my Dad. Now I don’t hear about “the Lord” anymore.

I unfollowed the other parents at my kid’s school. It didn’t take long.

I didn’t stop there.

I unfollowed the one who wears those Oakley sunglasses. I unfollowed the one with flaky ears. I unfollowed everyone with a Samsung phone. I unfollowed the one parked outside the Dave & Busters probably waiting to go inside. I was driving fast, I couldn’t be sure. Better to be cautious. I unfollowed the one who chose a heartbreaking brand of beer.

I unfollowed everyone who doesn’t appreciate how much effort I have put into my guilt.

|  10 Aug 2018




Bad Idea Rejection Tokens™

Something I really appreciate1 when I see it manifested in an engineering lead is the habit of letting subordinates’ arguments frequently win the day during run-of-the-mill code reviews, even when the lead remains skeptical or — especially — is in sharp disagreement with the proposed changes. Disagreeing but permitting isn’t a sign of weakness. In the context of a healthy team dynamic, it’s a sign of good leadership.

There are a finite number of Bad Idea Rejection Tokens™ that a lead can cash in before their teammates conclude that the team lead has a closed mind and a bad attitude. “I wouldn’t have done it that way” is not something an engineering lead should find themselves saying often during code review. Making a habit of rejecting your teammates’ work is toxic for morale and productivity. If instead the lead only occasionally exercises their veto powers, then the teammates can trust that when the lead rejects their work it isn’t motivated by stubbornness but by a good-faith effort to practice good judgment. Finding the right balance between permissiveness and restraint is key.


  1. Yep, it’s a good habit I’m seeing demonstrated at work these days, and I’m stoked about it. ↩︎

|  7 Aug 2018




Welcome Home (Pod), a Very Short Play About Apple’s Inexcusable Failure to Recognize Even Mildly Disfluent Speech

JARED
Hey Siri, play, uhh—

HOMEPOD
(Siri light turns on)

IPHONE, IPAD, APPLE WATCH
(Siri reacting on all of them)
Beep-beep!

JARED
(still thinking, all those devices reacting doesn’t help)
—umm…

HOMEPOD
(resumes playback of the previous song from an hour earlier)

IPHONE, IPAD, APPLE WATCH
(go dark again)

JARED
No! Stop!

HOMEPOD
(continues playing)

JARED
Stop playi—
(irritated, but finally remembering to use the key phrase)
Hey Siri—

IPHONE, IPAD, APPLE WATCH
Beep-beep!

JARED
—stop playing.

HOMEPOD
(stops)

The front door opens as HENRY, four-and-a-half years old, comes in the door after a weekend at his grandmother’s.

HENRY
Hi Daddy!
(notices the Home Pod)
What’s that?

JARED
It’s a Home Pod.

HENRY
Hōmpa?

JARED
(enunciating exaggeratedly)
Hō-muh Pô-duh.

HENRY
Home Pod? What’s it do?

JARED
It has Siri on it, it plays music.

Henry is excited. He’s thinking of a song in his dad’s “Henry” playlist called “Drift feat. RZA” that he’s been listening to at least twice a day for the past few weeks. He leans his face towards the top of the Home Pod.

HENRY
Play Drift!

The Home Pod does not respond.

JARED
No, you have to say “Hey Siri”

IPHONE, IPAD, APPLE WATCH
Beep-beep!

HOME POD
(lights up)

HENRY
Hey Siri! Play Drift!

HOME POD
Okay, playing Drift by Joshua Lee.
(wrong song starts playing)

HENRY
No! Siri, play Drift from Pacific Rim!

HOME POD
(unresponsive, continues playing wrong song)

JARED
No, you have to say
(quietly this time)
“Hey Siri”

HOME POD
(lights up, ducking the audio)

HENRY
Siri!
(with some disfluency typical of his age)
Play Pacifi— play Drift from Pacific Rim.

HOME POD
OK, here’s some Dr. Dre just for you.
(Dr. Dre starts)

HENRY
Hey Siri! Play the Drift song from Pacific Rim.

HOME POD
I couldn’t find “Fred’s F****g Pussy” in your library or on Apple Music.
(Dr. Dre resumes)

HENRY
Siri! Play the Drift song from Pacific— from Pacific Rim.

HOME POD
(Dr. Dre continues, unabated)

JARED
(loudly, over the music)
You’ve gotta say “Hey Siri”

IPHONE, IPAD, APPLE WATCH
Beep-beep!

HOME POD
(lights up, ducking the audio)

HENRY
Siri! Play Drift from Pacific Rim

HOME POD
I couldn’t find Drake Pacific Rim in your library or on Apple Music. (Dr. Dre continues)

JARED
Hey Siri, stop playing.

HOME POD
(stops)

HENRY
Hey Siri, play Drift from Pacific Rim

HOME POD
I couldn’t find Drift From Pacific Rim in your library or on Apple Music.

JARED
(enunciating exaggeratedly)
Hey Siri, play the song Drift from the Pacific Rim soundtrack.

HOME POD
OK, now playing “Drift featuring RZA” by Blake Perlman and RZA. (Correct song starts)

|  11 Feb 2018




Keep Screen Unlocked: ’sodes Feature for Folks Who Don’t Have CarPlay

Keep Screen Unlocked is a handy (optional) feature in ’sodes that keeps play controls accessible at all times. It isn’t a technical marvel by any stretch, but it comes in handy if you:

It’s not a universal use case, but it’s one that I’ve been in. Once you’ve enabled the feature in Settings.app, all that’s required to trigger the feature is for these three conditions to be met:

Why? Because this keeps ’sodes play controls accessible in a hurry. Without this, your phone’s display will eventually go dark and your screen will lock, requiring you to manipulate your phone before you can tap a pause button, if you can even tap it in iOS’ tiny Now Playing lock screen widget. That latter irrituation is why ’sodes play/pause button is so generously-sized. You can tap it easily even with your arm extended as your car bounces down the highway.

This setting is off by default. And even if you enable it, it will not engage unless all three conditions are met. Otherwise your normal locking behavior will take over.

If you (or someone you like a whole lot) would enjoy a more relaxing way to get into podcasts, please check out ’sodes. It launches February 15th, but is available for pre-order now.

|  8 Feb 2018




What’s the Deal with “No Downloads” In ’sodes?

One of the things you’ll notice first when using ‘sodes is that there are no downloads to manage. This isn’t one of those things where I ran out time. It’s a deliberate omission. This post is about why I made that decision, and also takes a quick look under the hood at the technical stuff that makes it work.

I have long wanted a podcast player that feels more like a TV-streaming app: tap a show, tap an episode, and listen. I know it’s possible to use other podcast players that way, but it’s tedious. You subscribe to a show and episodes start downloading. Eventually you have to go find where the settings are to turn off automatic downloads, but first you have to find all the active downloads and cancel them. Maybe you aren’t able to cancel them in time. Since those audio files count against your iPhone storage, you hunt down all the pesky downloads and delete them. Then when you finally start listening to an episode, you have to confirm it’s not re-downloaded.

For a lot of folks, all this stuff is part of the appeal. For me, managing downloads is a vestigial trait from when podcast players looked like this:

I made ’sodes because I think the experience should be better for casual users like me. There are no download queues to manage, no auto-deletion behaviors to configure, no inboxes to triage. You tap an episode and it plays. It requires an internet connection, yes, but so do video streaming apps1. My use case for podcast listening mirrors how I binge watch pleasantly-shitty Netflix shows about crusty-but-benign police lieutenants and ex-Supreme Court justices and managing editors.

Because ’sodes doesn’t have any of the baggage of an old-school podcast player, the design is airy and streamlined. There’s no need for a tab bar or a navigation bar. There are no inboxes or queues. Many times there’s not even a need to leave the app’s home screen. Your most favorite shows and a handful of recent episodes are already there:

Behind the scenes, playing a podcast audio file is different than streaming a TV show. Services like Netflix use technologies like HTTP Live Streaming (HLS) to serve video on-demand. HLS plays video at variable levels of quality so playback can be adjusted for slow connections or metered usage. HLS requires the content provider to encode the video in a range of qualities, fragmented into hundreds of small files. Podcast producers don’t do that. Podcasts are encoded as one-size-fits-all MP3 files. “Streaming” a podcast is not really streaming but downloading on demand.

So how does ’sodes manage on-demand downloads? Because on-demand playback of a podcast is only able to use the original quality MP3, I want to keep network usage to a minimum. Users should feel comfortable using ’sodes on a cellular network. I limit network usage via an obscure but powerful API that Apple provides called AVAssetResourceLoaderDelegate (if you want to read an even deeper dive click here). This API allows the developer to take over control of fulfilling all the audio data requests coming from the system audio framework. Whenever the system requests a range of audio data for an episode, I first check a local file to see if I have any of those byte ranges:

If I have the data already, I use it. If there are any gaps, I only download the data it takes to fill in the gaps. I never download any data that’s not explicitly requested by the system audio framework. In this manner, you can take several app sessions to finish listening to an episode, but ’sodes won’t download any given byte of data more than once. This drastically reduces network usage without requiring you to manage a download. Further, this cached data is stored in a location on your iPhone that is managed automatically by the operating system and doesn’t count against your iPhone storage. ’sodes keeps audio data for a handful (currently 3) of the most recently-played episodes so that you can switch between a few episodes when you have a spare moment without triggering more data usage.

If you (or someone you like a whole lot) would enjoy a more relaxing way to get into podcasts, please check out ’sodes. It launches February 15th, but is available for pre-order now.


  1. Yeah, I know Netflix (and maybe others) have started adding offline modes, but those are buried inside secondary screens and are not allowed to get in the way of the primary casual experience. ↩︎

|  3 Feb 2018




Apple Watch Series 3 First Impression: Mindblown.gif

TL;DR

This might be the most delightful Apple product I’ve ever purchased. It feels like an inflection point in the story arc of consumer devices. The addition of cellular isn’t iterative. It’s revolutionary. In other words:

Scattered Observations

Little Nits


  1. I was mistaken about AnyList. Here’s a quote from Jason Marr, one of the developers of AnyList: “The AnyList app for Apple Watch syncs directly with the AnyList iPhone app and stores data locally on the watch so it can be used to view and modify lists even when the watch is not connected to the phone. However, the watch app does not currently support syncing over LTE, so modifications to a list that occur while the watch is disconnected from the phone will not sync to / from the watch until the next time the watch and phone are connected." ↩︎

|  25 Sep 2017




Get Your Architecture Right, Because You Always Have More Time than You Think You Do

When facing an anxiety-provoking deadline for a software project, you have more time to plan your architecture than it may seem. Indeed, you should consider near and medium term requirements and risks to the full extent that it is possible to consider them given current knowledge, even if you choose not address any of them up front. Take only calculated risks. Factor those risks carefully into your initial implementation. Do not touch a keyboard until you have done so. Cut corners, but cut them thoughtfully.

Urgency Versus Anxiety

It’s worth noting the important difference between a sense of urgency and anxiety. Before I got into software development I was a registered nurse in an ICU. One evening a patient went into cardiac arrest. In an instant, the room filled with nurses and other folks eager to jump in and help. I was leaning over the patient’s bed giving chest compressions to keep the patient’s blood flowing. I felt myself swarmed by a small crowd in scrubs and Crocs. There were more people present than necessary, and it made the atmosphere in the room ratchet up from an appropriate urgency to a palpable anxiety. A supervising physician on the scene wisely ordered everyone not currently providing care to leave the room. As the excess folks filed out, I overheard the physician mention something to a colleague about the dangerous anxiety he was correcting:

I’ll never forget something an instructor told me in med school about situations like this, “You always have more time than you think you do.”

He wasn’t addressing me directly, but the lesson stuck: there will never be a medical situation so dire that you literally cannot spare a moment to consider an appropriate course of action. There’s no use for anxiety in the mind of a professional doing his or her duty in a crisis. March all the unnecessary anxious thoughts out of your mind and make room for a deliberate response. Give yourself permission to think. In the years since that day, I’ve found this lesson to be very valuable, even outside of healthcare. Strange as it may seem, I hear echoes of it in my process for sketching out architectural roadmaps for the applications I work on.

(Fr)agile

In an ideal world, agile processes are adhered to with perpetual regularity, pulsing in a cadence of small, iterative changes. In the real world, an organization that can unwaveringly adhere to an agile process is hard to come by. Customer demands, public events, and other factors create constraints that require setting a fixed ship date for a product launch. This is lethal to an agile process because there’s no margin of error for iteration. You don’t have the luxury of repeated revisions. You barely have time to ship your first draft. Under these conditions, the anxiety of the engineers on such a project skyrockets. Facing a tall list of requirements and a fast-approaching, narrow delivery window, there is a temptation to bust out the keyboards and hammer out some code because how will we ever finish unless we can show immediate and significant progress oh god oh god. Invariably, code written in thoughtless haste is unmaintainable or, worse, unshippable. Technical debt is accumulated at an unacceptable rate. Inappropriate patterns are chosen and implemented haphazardly.

Breaking it Down

It is difficult to break a down a set of large problems into atomic problem units which can be distributed among a team of developers and solved in parallel. In a healthy agile process, there is no single delivery date, but an ongoing process of experimentation and refinement. Impedance mismatches between the output of developers working on separate components are addressed through repeated course corrections. You fully roll out a feature only when it’s ready to be. But when there’s an aggressive and fixed delivery date, there’s no room in the process for such refinements. Each component has to be shippable in its first iteration, and it has to immediately lock into place alongside all the other components.

Under the pressure of a looming deadline, developers may spend an inadequate amount of time considering their architectural roadmap. At worst, this leads to a code base that fails to satisfy the launch-day product requirements on time. At best, the code produced is ill-suited for the life of the product immediately after launch. There’s no agile process in place to carry it through future milestones, so the cycle of fixed delivery deadlines and frantic architectural changes repeats until the product fails.

Here’s a metaphor for the problem. Consider an illustrator tasked with drawing a human figure. A trained illustrator works like this:

She begins with gesture lines and primitive shapes, blocking out the pose, proportions, and perspective. Progressive levels of detail are added, guided by those initial lines and shapes, until the drawing arrives at its intended appearance. Inexperienced artists try to begin at the end, drawing body contours without the aid of any primitive elements, or they hastily jot down the gesture lines and shapes without regard for proportion and perspective. Either way the result is unsatisfactory.

Carrying the metaphor, what I have seen anxious developers do is start with the far right drawing without any gesture lines. They task team members with drawing each limb separately and at a premature level of detail. When at last the team attempts to pin the components together the perspectives don’t match, the proportions are childish, and the result is hideously unusable. The irony is that — just as a rough pass of detail over an expertly-arranged set of gesture lines can yield a pleasantly unfinished portrait — a simple overlay of features and polish atop an expertly-ordered primitive architecture is the very definition of a minimally-viable product.

There’s another software development pitfall suggested by this metaphor. Accurate and pleasant gesture lines are extraordinarily difficult to master. They may look like stick figures to an untrained eye, but they’re anything but. Countless hours of practice and studious observation are required to become proficient at drawing these primitive shapes. If you undertake them without care, the resulting drawing will have all the same flaws as a drawing made without any gesture lines. In the same way, an architectural roadmap must be considered with extreme care. Don’t just list everything you know, list everything you don’t or can’t know. You don’t have to plan every detail, but you must wrestle with the problem area long enough to be reasonably confident that your architecture will be both efficient in the short term and stable for the medium term. If you’re lucky it will be stable for the long term. No matter what you choose, it’ll always be a guess. But make it a well-educated guess.

A Concrete Example

Here’s a concrete example of the kind of discussion I think can be spared some time at the beginning of a project without making commitments that over- or under- engineer things. Consider an app backed by a web service with user-specific accounts. Questions that might come up during a planning phase:

And the key points during that discussion might be:

Please note I’m not arguing for one way of the other here. I’m merely sketching out some terrain over which such a discussion might traverse.

Conclusion

In the end there’s always risk. You make the best choice you can given the information you have. I recommend discussing at length both the near and medium term before comitting to a near-term plan. All too often, these discussions either don’t happen or they happen in a rush and so risks aren’t considered to the full extent that it is possible to consider them given current knowledge.

That last line is the bad habit that rubs me wrong:

the risks aren’t considered to the full extent that it is possible to consider them given current knowledge.

This is the point of the quote from that ICU physician I admired so much. You always have more time than it seems like you do. You always have time to consider the impact of what you know and what you don’t, even if you choose not to address any of the risks up front, even if the outcome of that consideration means cutting huge corners. At least the risks you’re taking are calculated.

|  20 Sep 2017




The Leftovers is Over

I could write a book about The Leftovers, or somebody could, maybe not me. I can’t recall a show that so deliberately avoided answering its own questions and still managed not to blot out any of the emotion or struggle of its characters. There’s so much to praise, to expound upon, but that’s not something I can contribute. I will add this note, however: the Sudden Departure is a metaphor for our world, for the cosmos: undeniably miraculous, unspeakably violent, raising endless questions which it answers only with infinite silence.

|  5 Jun 2017




Tune in Next Time for “Last-Minute WWDC Comments” or “Apple Isn’t Doomed to Fail, But Their Future Doesn’t Look as Rosy as Their Past”

I’ve been thinking a lot about Apple’s biggest success stories. The products that mattered all rode currents outside of Apple’s control:

Considering Apple’s more recent projects against the market currents we see today, the picture is gloomy:

So what does that leave?

As an Apple fan, this is pretty depressing. My expectations for today’s announcements are very low.

|  5 Jun 2017