WEBVTT 00:00.360 --> 00:03.300 -: A useful tool for delivering simple results is 00:03.300 --> 00:05.070 something we call working backwards. 00:05.070 --> 00:07.140 And this used to be a really core part 00:07.140 --> 00:08.700 of the culture at Amazon. 00:08.700 --> 00:10.620 Not sure if it still is, but I hope it is. 00:10.620 --> 00:11.580 It's a good way 00:11.580 --> 00:13.650 of really approaching things from a simple standpoint 00:13.650 --> 00:15.510 that just delivers the results that you need. 00:15.510 --> 00:16.800 Here's how it works. 00:16.800 --> 00:18.330 The idea is that you work backwards 00:18.330 --> 00:21.180 from the customer experience that you're trying to deliver, 00:21.180 --> 00:23.550 and then you just figure out the simplest technical solution 00:23.550 --> 00:25.290 to deliver that experience. 00:25.290 --> 00:27.120 That's in contrast to working forwards 00:27.120 --> 00:29.640 from cool technology that you want to use. 00:29.640 --> 00:31.860 Those are solutions in search of a problem. 00:31.860 --> 00:34.020 So if you say, "Hey, deep learning is cool 00:34.020 --> 00:36.240 and we really wanna play with deep learning," 00:36.240 --> 00:37.530 thinking up ways to use that 00:37.530 --> 00:39.690 and apply that to business problems 00:39.690 --> 00:41.310 is not going to be working backwards. 00:41.310 --> 00:44.220 That's working forwards from trendy technology. 00:44.220 --> 00:45.930 Again in that example we talked about in the 00:45.930 --> 00:48.270 previous lecture if we were working forwards, 00:48.270 --> 00:50.880 we might apply deep learning to this recommender system, 00:50.880 --> 00:51.810 but working backwards 00:51.810 --> 00:53.610 we might have seen that a much simpler solution 00:53.610 --> 00:55.920 like just reviewing well rated products 00:55.920 --> 00:57.120 within the given category 00:57.120 --> 01:00.360 or using a graph database lookup would work just as well 01:00.360 --> 01:02.310 with a lot fewer moving parts. 01:02.310 --> 01:04.500 So you don't wanna have solutions in search of a problem. 01:04.500 --> 01:06.690 You want problems in search of a solution. 01:06.690 --> 01:08.340 So for an example, 01:08.340 --> 01:11.280 let's say that I want to have an achievement system 01:11.280 --> 01:14.370 on some forum or something where I give 01:14.370 --> 01:16.680 people little badges for having the most posts 01:16.680 --> 01:18.990 or the most replies or uploads or something. 01:18.990 --> 01:20.940 I could use blockchain to do that 01:20.940 --> 01:23.310 and store that information using blockchain 01:23.310 --> 01:25.920 because blockchain is fun and cool and trendy 01:25.920 --> 01:28.140 but there's no reason to do that. 01:28.140 --> 01:30.780 So the customer does not care, right? (chuckles) 01:30.780 --> 01:32.700 You need to work backward from the customer experience. 01:32.700 --> 01:34.890 They just wanna get their badge, they wanna show it off. 01:34.890 --> 01:37.170 And you do not need blockchain to do that. 01:37.170 --> 01:38.340 Just because you think it's cool 01:38.340 --> 01:40.200 and trendy doesn't mean that's the right solution. 01:40.200 --> 01:41.700 It might be overly complex. 01:41.700 --> 01:43.830 What happens when blockchain goes outta style, 01:43.830 --> 01:45.390 yada, yada yada. 01:45.390 --> 01:47.220 We talked about the deep learning example already. 01:47.220 --> 01:49.710 A lot of times the database search will do just fine 01:49.710 --> 01:52.785 or using quantum computing for, well, anything right now. 01:52.785 --> 01:53.618 (chuckles) 01:53.618 --> 01:54.960 I mean it's a fun research topic, 01:54.960 --> 01:57.000 but my gosh, don't even go there. 01:57.000 --> 01:58.410 Stay focused on results. 01:58.410 --> 02:01.350 You need to focus on the experience you're delivering, 02:01.350 --> 02:03.270 meeting the requirements you were given, 02:03.270 --> 02:05.850 and developing a technical solution 02:05.850 --> 02:06.870 to meet those end results. 02:06.870 --> 02:09.090 Working backwards from the results you're delivering 02:09.090 --> 02:10.680 instead of forwards from the technology 02:10.680 --> 02:11.943 that you want to use. 02:13.230 --> 02:15.120 Here are some tools for doing that. 02:15.120 --> 02:17.370 So one thing we did at Amazon was starting with actually 02:17.370 --> 02:19.410 writing a press release for every new project. 02:19.410 --> 02:21.420 So we wrote a little press release 02:21.420 --> 02:22.800 and press release format 02:22.800 --> 02:24.060 announcing what we were building 02:24.060 --> 02:27.000 and why customers should be excited about it. 02:27.000 --> 02:28.140 And that allowed us to frame 02:28.140 --> 02:29.700 and think about what we're actually delivering 02:29.700 --> 02:30.810 to the customers, 02:30.810 --> 02:33.330 why the customers would find this helpful and useful. 02:33.330 --> 02:36.180 And then we could think about what sort of technology 02:36.180 --> 02:38.460 we could build to deliver what that press release 02:38.460 --> 02:39.720 was promising. 02:39.720 --> 02:41.310 So if you're building something that the world 02:41.310 --> 02:43.230 will be excited about, 02:43.230 --> 02:44.670 that's what matters at the end of the day. 02:44.670 --> 02:46.770 How it gets done under the hood they don't care, 02:46.770 --> 02:48.390 as long as it works reliably 02:48.390 --> 02:50.640 and does what you want it to do. 02:50.640 --> 02:51.990 Again, you should design your systems 02:51.990 --> 02:53.940 from the customer backwards. 02:53.940 --> 02:55.260 So how do you do that? 02:55.260 --> 02:57.600 Well, if you're thinking about the customer experience, 02:57.600 --> 02:59.070 what the customer sees 02:59.070 --> 03:01.410 is usually some sort of user interface, all right? 03:01.410 --> 03:03.840 So start with what builds that user interface. 03:03.840 --> 03:06.240 What sort of web servers are you using to host that? 03:06.240 --> 03:08.100 What platform is it running on? 03:08.100 --> 03:08.940 What services? 03:08.940 --> 03:11.610 Then working backwards a little bit more will power that UI. 03:11.610 --> 03:14.700 So what databases do I need to feed a data? 03:14.700 --> 03:16.380 What services do I need to build 03:16.380 --> 03:17.880 in front of those databases? 03:17.880 --> 03:21.780 What caching layers do I need to power that user experience? 03:21.780 --> 03:22.830 Work backwards further. 03:22.830 --> 03:25.590 Where does that data come from that powers these services? 03:25.590 --> 03:26.423 How do I generate it? 03:26.423 --> 03:28.200 How do I collect it, right? 03:28.200 --> 03:30.870 So working backwards from what you're delivering 03:30.870 --> 03:33.090 will lead you down to those lower level details 03:33.090 --> 03:36.000 and technical decisions as opposed to working forward 03:36.000 --> 03:38.190 from some preconceived notion you have 03:38.190 --> 03:40.500 of the technology that you want to use. 03:40.500 --> 03:42.450 So, very important technique here. 03:42.450 --> 03:45.180 Focus on what you're delivering, meeting your requirements 03:45.180 --> 03:47.220 and you'll be far more likely to deliver a system 03:47.220 --> 03:48.450 that meets your needs 03:48.450 --> 03:50.190 and is not overly complex. 03:50.190 --> 03:54.030 That means you'll deliver it most likely on time 03:54.030 --> 03:55.650 and it will be easy to maintain 03:55.650 --> 03:57.600 and everybody will be happy in the long run. 03:57.600 --> 04:00.630 Yes, engineers want to work on complex systems, 04:00.630 --> 04:02.190 so do you, right? 04:02.190 --> 04:03.990 I've seen situations where we call it 04:03.990 --> 04:05.490 retention driven development, 04:05.490 --> 04:07.680 where people do work forwards from 04:07.680 --> 04:10.410 interesting technologies just to keep their engineers happy 04:10.410 --> 04:12.750 'cause they're so afraid of losing them in this environment. 04:12.750 --> 04:14.400 But you can compensate for that. 04:14.400 --> 04:17.580 Again, if you're the team that gets stuff done, 04:17.580 --> 04:18.510 that's addictive. 04:18.510 --> 04:20.070 People wanna be a part of that team 04:20.070 --> 04:24.127 and maybe you can give your engineers outlets for R&D work. 04:24.127 --> 04:25.740 One thing I used to do 04:25.740 --> 04:27.810 was hold these monthly sessions 04:27.810 --> 04:29.760 where we just read through a latest research paper 04:29.760 --> 04:30.630 and talked about it 04:30.630 --> 04:33.090 and brainstormed ideas about how it might be relevant 04:33.090 --> 04:34.140 to what we're doing. 04:34.140 --> 04:35.400 You wanna make sure that people are staying 04:35.400 --> 04:37.530 on top of the latest developments in their field. 04:37.530 --> 04:39.240 That's always important for people, 04:39.240 --> 04:40.410 but it doesn't mean you need to apply 04:40.410 --> 04:43.020 those latest developments to every project, right? 04:43.020 --> 04:44.310 Maybe you're giving them some little bit of time 04:44.310 --> 04:48.060 on the side too to experiment with these things as well. 04:48.060 --> 04:50.010 If you are that productive, 04:50.010 --> 04:52.140 odds are you can take a few hours a week 04:52.140 --> 04:53.760 to let your engineers experiment with new things 04:53.760 --> 04:55.080 and try new ideas 04:55.080 --> 04:56.640 and maybe experiment with some of these 04:56.640 --> 04:58.290 more complex techniques. 04:58.290 --> 05:00.150 Sometimes it works out. 05:00.150 --> 05:03.660 I remember when I was running recommender systems at Amazon 05:03.660 --> 05:05.430 there was one guy who came up with an idea 05:05.430 --> 05:08.280 of using something called latent semantic analysis 05:08.280 --> 05:09.930 to generate recommendations. 05:09.930 --> 05:11.130 And at the time everyone was like 05:11.130 --> 05:13.110 that's overly complex, that's crazy. 05:13.110 --> 05:14.790 Well, something simpler we'll do. 05:14.790 --> 05:17.040 But he got really interesting results out of it. 05:17.040 --> 05:20.490 And by taking the time to just prototype it on the side, 05:20.490 --> 05:22.890 it was actually very educational for the team 05:22.890 --> 05:25.380 and informed some of our decisions going forward. 05:25.380 --> 05:26.610 So it's not either or, 05:26.610 --> 05:28.980 you don't have to abandon all cool technology 05:28.980 --> 05:31.800 just to favor simple solutions. 05:31.800 --> 05:33.100 Sometimes you can do both.